Nootan solutions for Chemistry Part 1 and 2 [English] Class 12 ISC chapter 7 - p-Block Elements [Latest edition]

Why is dinitrogen unreactive at ordinary temperature?

What happens when dinitrogen is passed over calcium carbide at 1300 K?

What happens when magnesium nitride is treated with water?

What happens when ammonia is treated with excess of chlorine?

What happens when nitric acid is poured over saw dust?

What happens when nitric acid is treated with gold?

Why is solubility of ammonia in water very high?

Explain why a precipitate of silver chloride dissolves in NH₄OH.

Explain, why zinc sulphate does not give a precipitate with excess of NH₄OH.

Explain, why nitric acid makes wool yellow.

Why does oxygen not show oxidation states of +4 and +6, whereas sulphur does so?

What type of hybridisation is involved for oxygen in H₂O? Give reason for your answer.

Give the structure of sulphur tetrafluoride.

Discuss briefly the properties of group 16 elements.

Define catenation and illustrate with example.

Arrange H₂S, H₂O, H₂Se, H₂Te in the order of decreasing thermal stability.

Explain the hybridisation in SF₆ molecule.

What is the shape of SF₆ molecule?

What is the oxidation state of sulphur in the following?

Sulphurous acid

What is oxidation state of sulphur in the following?

Sulphuric acid

What is the oxidation state of S in the following oxoacid?

Dithionic acid

What is the oxidation state of S in the following oxoacid?

Peroxodisulphuric acid

What type of hybridisation does explain the trigonal bipyramidal shape of SF₄?

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to metallic/non-metallic character.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to catenation.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to thermal stability of hydrides.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to oxidation states.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to allotropy.

Draw the structure of peroxymonosulphuric acid. 

Which has the larger bond angle H₂S or H₂O and why?

Explain the following observation:

Among the hydrides of elements of group 16, water shows unusual physical properties.

Give reasons for the following:

Sulphur in vapour state shows paramagnetic behaviour.

Account for the following:

Tendency to show −2 oxidation state diminishes from sulphur to poloniuum in group 16.

Account for the following:

NO₂ readily forms a dimer whereas ClO₂ does not.

Assign appropriate reason for the following observation.

SF₆ is not easily hydrolysed whereas SF₄ is easily hydrolysed.

Assign appropriate reason for the following observation.

Sulphur in vapour state exhibits some paramagnetic behaviour.

Give reason for the following statement:

SF₆ is not easily hydrolysed though thermodynamically it should be.

Give reason for the following fact:

Sulphur disappears when boiled with an aqueous solution of sodium sulphite.

Give reason for the following fact:

H₂SO₄ is a diprotic acid.

Assign a reason for the following:

Sulphur hexafluoride is used as a gaseous electrical insulator.

SF₆ is known but SCl₆ is not. Why?

Assign a reason for the following:

SF₆ is not easily hydrolysed.

Discuss the structure:

SO₂

Discuss the structure:

SO₃

What is allotropy?

Why is ozone regarded as an allotrope of oxygen?

Why is ozone used as a disinfectant?

What is tailing of mercury?

How is ozone formed in the upper atmosphere?

How is ozone useful for us?

What happens when ozone is passed in an acidified solution of ferrous sulphate?

What happens when moist sulphur is treated with ozone?

What happens when ozone is passed in an aqueous solution of potassium iodide?

Out of oxygen and ozone, which is a better oxidising agent and why?

How is ozone prepared?

Discuss the structure of ozone.

Describe the important oxidation reactions of ozone.

What happens when ozone is treated with ethylene?

What happens when ozone reacts with potassium iodide?

What happens when black lead sulphide is treated with ozone?

What happens when ozone is treated with an aqueous solution of potassium manganate?

Why is it that molecular nitrogen is not particularly reactive?

Among the hydrides of group 15, predict the hydride having highest thermal stability.

Among the hydrides of group 15, predict the hydride having largest bond angle.

Among the hydrides of group 15, predict the hydride having lowest boiling point.

Among the hydrides of group 15, predict the hydride having maximum reducing power.

Among the hydrides of group 15, predict the hydride having least basic character.

Write the names and structures of oxoacids of phosphorus in which phosphorus exists in +1 oxidation state.

Write the names and structures of oxoacids of phosphorus in which phosphorus exists in +3 oxidation state.

Write the names and structures of oxoacids of phosphorus in which phosphorus exists in +5 oxidation state.

Complete the following chemical equation:

\[\ce{Ca3P2 + H2O ->}\]

Complete and balance the following reaction:

\[\ce{N2O4 + NO ->[250 K]}\]

Complete and balance the following chemical equation:

\[\ce{Pb(NO3)2 ->[Heat]}\]

Complete and balance the following reaction:

\[\ce{NH3 + NaOCl ->}\]

Write the state of hybridisation of nitrogen in \[\ce{NO^-_3}\] ion.

Write the structure of pyrophosphoric acid.

Nitrogen exists as diatomic molecule and phosphorus as P₄. Why?

Explain giving reason the following:

SF₆ is known but SH₆ is not known.

Arrange the following in the decreasing order of property indicated:

H₂O, H₂S, H₂Se, H₂Te (boiling point)

Arrange the following in the decreasing order of property indicated:

NH₃, PH₃, AsH₃, SbH₃ (basic strength)

Why are all the P-F bonds in PF₅ molecule not of the same length?

Why does oxygen not show oxidation states of +4 and +6, whereas sulphur does so?

What type of hybridisation is involved for oxygen in H₂O? Give reason for your answer.

Give the structure of sulphur tetrafluoride.

Discuss briefly the properties of group 16 elements.

Define catenation and illustrate with example.

Arrange H₂S, H₂O, H₂Se, H₂Te in the order of decreasing thermal stability.

Explain the hybridisation in SF₆ molecule.

What is the shape of SF₆ molecule?

What is the oxidation state of sulphur in the following?

Sulphurous acid

What is oxidation state of sulphur in the following?

Sulphuric acid

What is the oxidation state of S in the following oxoacid?

Dithionic acid

What is the oxidation state of S in the following oxoacid?

Peroxodisulphuric acid

Account for the following:

NH₃ has higher boiling point than PH₃.

Account for the following:

H₃PO₃ is a diprotic acid.

Account for the following:

OF₂ should be called oxygen difluoride and not fluorine oxide.

What type of hybridisation does explain the trigonal bipyramidal shape of SF₄?

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to metallic/non-metallic character.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to catenation.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to thermal stability of hydrides.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to oxidation states.

Describe the properties of O, S, Se, Te and Po (group 16 elements) with reference to allotropy.

PH₃ forms bubbles when passed slowly in water but NH₃ dissolves. Explain why?

Draw the structure of peroxymonosulphuric acid. 

State the type of hybrid orbitals associated with P in PCl₅.

State the type of hybrid orbital associated with S in SF₆.

What is the nature of bonds in NO₂ molecule?

Which has the larger bond angle H₂S or H₂O and why?

Describe the manufacturing of H₂SO₄ by the contact process.

Discuss the structure of PCl₃.

Oxides of nitrogen have open chain structure while those of phosphorus have closed chain or cage structures. Why is it so? Illustrate with one structural example for each type of oxides.

Which type of hybridization is present in the ammonia molecule?

What is the expected bond angle in NH₃?

Explain the following observation:

Among the hydrides of elements of group 16, water shows unusual physical properties.

Explain the following observation:

Unlike phosphorus, nitrogen shows little tendency for catenation.

Explain the following observation:

Unlike phosphorus, nitrogen shows little tendency for catenation.

Explain the following observation:

Sulphur in vapour state exhibits paramagnetic behaviour.

Account for the following:

Tendency to show −2 oxidation state diminishes from sulphur to poloniuum in group 16.

Account for the following:

NO₂ readily forms a dimer whereas ClO₂ does not.

Account for the following:

PH₃ is a weaker base than NH₃.

Account for the following:

SF₆ exists but OF₆ does not.

Account for the following:

Sulphur exhibits tendency for catenation but oxygen does not.

Assign appropriate reason for the following observation:

Phosphinic acid behaves as a monoprotic acid.

Assign appropriate reason for the following observation.

SF₆ is not easily hydrolysed whereas SF₄ is easily hydrolysed.

Give reason for the following:

Red phosphorus is less reactive than white phosphorus.

Assign appropriate reason for the following observation.

Sulphur in vapour state exhibits some paramagnetic behaviour.

Give chemical reaction in support the following:

All the bonds in PCl₅ molecule are not equivalent.

Give chemical reaction in support of the following:

Sulphur exhibits greater tendency for catenation than selenium.

Give reason for the following statement:

SF₆ is not easily hydrolysed though thermodynamically it should be.

Give reason for the following:

Nitric oxide becomes brown when released in air.

Give reason for the following:

PCl₅ is ionic in the solid state.

Give reason for the following fact:

Sulphur disappears when boiled with an aqueous solution of sodium sulphite.

Give reason for the following fact:

H₃PO₄ is a diprotic acid.

Assign a reason for the following:

In group 15, the bond angle \[\ce{H - M - H}\] decreases in the following order: NH₃ (107.8°), PH₃ (93.6°), AsH₃ (91.8°).

Assign a reason for the following:

Sulphur hexafluoride is used as a gaseous electrical insulator.

SF₆ is known but SCl₆ is not. Why?

Assign a reason for the following:

Not all bonds in a molecule of PCl₅ are equivalent.

Assign a reason for the following:

SF₆ is not easily hydrolysed.

Write chemical equation for the following reaction:

\[\ce{Ca3(PO4)2 + SiO2 + C ->}\]

Write the structures of the following molecule: 

H₂SO₃

Draw the structure of the following:

H₂SO₄

Draw the structure of the following:

H₂S₂O₇

Describe the following about halogen family elements:

Relative oxidising power

Describe the following about halogen family elements:

Relative acid strength of hydrides.

Describe the following about halogen family elements:

Oxoacids and their relative oxidising ability

What are interhalogen compounds?

How are interhalogen compounds classified?

Give the structure of IF₇.

Discuss briefly the properties of group 17 elements (halogen family).

State two examples of compounds in which halogens exhibit higher oxidation state.

Arrange the following in the order of property indicated for the given set:

HF, HCl, HBr, HI - increasing acid strength.

Arrange the following according to the property mentioned against the given:

HClO₄, HIO₄, HBrO₄ in the order of increasing oxidising ability.

Account for the following:

HI in aqueous solution is a stronger acid than hydrochloric acid.

Account for the following:

Noble gases exhibit low chemical activity.

Name a compound in which chlorine displays an oxidation state of +7.

Write the balanced equation for the following reaction:

\[\ce{BrO^-_3 + F2 + OH- ->}\]

Which one among the following is the strongest oxidising agent?

\[\ce{ClO^-_4, BrO^-_4, IO^-_4}\]

Why is HF the weakest acid among hydrohalo acids inspite of the fact that fluorine is most electronegative?

Arrange the following in decreasing order of property indicated:

F₂, Cl₂, Br₂, I₂ (bond energy)

Arrange the following in the increasing order of the property mentioned:

MF, MCl, MBr, MI (ionic character)

Write an example of a neutral molecule which is isoelectronic to ClO⁻.

Explain, why is the boiling point of hydrogen fluoride higher than that of hydrogen chloride?

Give two examples of pseudohalogens.

What are noble gases and why are they called so?

Write the names and electronic configurations of all the noble gases.

Write the structures of the following molecule: 

XeOF₄

Complete the equation:

\[\ce{XeF4 + H2O ->}\]

Name the molecular geometry of XeOF₄.

Complete and balance the following equation:

\[\ce{XeF6 + KF ->}\]

Explain, why does neon not form compounds analogous to those formed by xenon?

Name the molecular geometry of XeO₃.

What is the state of hybridisation of Xe in XeF₂?

What is the state of hybridisation of Xe in XeF₆?

What is the state of hybridisation of Xe in XeO₃?

What is the state of hybridisation of Xe in XeF₄?

Complete the following equation: 

\[\ce{XeF2 + H2O ->}\]

Complete the equation:

\[\ce{XeF4 + H2O ->}\]

Complete the following reaction.

\[\ce{XeF6 + H2O ->}\]

Complete and balance the following reaction:

\[\ce{XeF6 + SiO2 ->}\]

Explain the shape of XeF₄ on the basis of VSEPR theory.

What products are formed when XeF₄ is hydrolysed?

Why are interhalogen compounds more reactive than the related elemental halogens?

State reason for the following:

Fluorine provides the largest variety of interhalogen compounds amongst halogens.

Why are fluorine and oxygen compounds more aptly called oxygen fluorides?

Fluorine has lower electron affinity than chlorine and yet it is a stronger oxidising agent than chlorine. Explain.

Of HI and HCl which has a weaker covalent bond and what effect has it on their acid strengths?

NaOCl solution becomes unstable on warming. What happens to it?

Draw the structure of the following molecule: 

XeF₄

Draw the structure of SF₄ molecule.

Give appropriate reason for each of the following observation:

Of the noble gases, only xenon is known to form chemical compounds.

Give appropriate reason for the following observation:

Despite its lower electron affinity, fluorine is a stronger oxidising agent than chlorine.

Why is HF not stored in plain glass bottles?

Give appropriate reason for the following observation:

Only higher members of group 18 of the periodic table are expected to form compounds.

Fluorine has lower electron affinity than chlorine and yet it is a stronger oxidising agent than chlorine. Explain.

Account for the following:

NO₂ readily forms a dimer whereas ClO₂ does not.

Draw the structure of \[\ce{SiF^{2-}_6}\].

Draw the structure of the following molecule: 

XeF₄

Write the structures of the following molecule: 

XeOF₄

Give chemical evidence for the following:

Fluorine is a stronger oxidising agent than chlorine.

Assign appropriate reason for the following:

Hydrogen fluoride is a much weaker acid than HCl in aqueous solution.

Assign appropriate reason for the following:

The bond energy of F₂ is less than that of Cl₂.

Assign appropriate reason for the following:

Bleaching of flowers by Cl₂ is permanent while by SO₂ is temporary.

Complete the following equation: 

\[\ce{XeF2 + H2O ->}\]

Write balanced chemical equation for the following reaction:

\[\ce{XeF4 + SbF5 ->}\]

Write balanced chemical equation for the following reaction:

\[\ce{U + ClF3 ->}\]

Balance the following equation:

\[\ce{XeF6 + H2O -> XeO2F2 + HF}\]

Complete the following reaction equation:

\[\ce{CaOCl2 + HCl ->}\]

Write the structures of the following:

IF₅

Write the structure of the following:

XeOF₃

Draw the structure of the following:

XeO₃

Answer the following.

Draw structures of XeF₂.

Write the structural formula for IF₃.

Draw the structure of hypochlorous acid.

Draw the structure of chlorous acid.

Write the structures of the following molecule: 

XeOF₄

Draw the structure of the following:

XeO₃

Among groups 14 and 15, the elements of which group are less metallic?

How does the metallic character vary in group 15?

What type of multiple bonds are present in N₂ molecule?

What is the molecular formula of a white phosphorus molecule?

What is the shape of a white phosphorus molecule?

Name the shape of the hydrides of group 15 elements.

Arrange the hydrides (MH₃) of group 15 elements in the decreasing order of thermal stability.

Arrange the hydrides (MH₃) of group 15 elements in the decreasing order of basic character.

Arrange the hydrides (MH₃) of group 15 elements in the decreasing order of reducing character.

Name the shape of PCl₃ molecule.

Name the shapes of PCl₅ molecule.

Among N₂O₃, P₄O₆ and As₄O₅, which is most acidic?

Write the formulae of the oxoacids of phosphorus in which phosphorus is present in +5 oxidation state.

What is the basicity of phosphorus acid (H₃PO₃)?

What are chalcogens?

Write the valence shell electronic configuration of group 16 elements.

Write the molecular formula of sulphur.

Which has a higher electron affinity, O or S?

Write the formula of a compound in which oxygen exists in +2 oxidation state.

Can oxygen exist in +6 oxidation state?

What type of hybridisation is usually involved in the compounds containing sulphur in +6 oxidation state?

Name the metal(s) which belong(s) to group 16.

Write the formulae of the allotropes of oxygen.

What type of hybridisation is involved in the formation of a H₂O molecule?

Arrange H₂O, H₂S, H₂Se and H₂Te in the decreasing order of volatility.

Arrange H₂O, H₂S, H₂Se and H₂Te in the decreasing order of acidic character.

Does water act as a reducing agent?

What is the shape of SF₆ molecule?

Draw the structure of SO₃ molecule.

Why are the elements of group 17 called ‘halogens’?

Name a halogen which exists as a solid at room temperature.

The elements of which group do have the smallest atomic radii in respective periods?

How does the following property vary on moving down group 17?

Density

How does the following property vary on moving down group 17?

Electron affinity

How does the following property vary on moving down group 17?

Ionisation energy

Among the halogens, which has the highest electron affinity?

Can fluorine exhibit positive oxidation states?

Can iodine displace chlorine from NaCl solution?

Which hydrogen halide does exist in the liquid state at 290 K?

Arrange halogen acids in the decreasing order of thermal stability.

Arrange halogen acids in the decreasing order of reducing power.

Arrange the halogen acids in the decreasing order of acidic strength.

What is the name of the compound OF₂?

What is the general formula of perhalic acids?

Among HCIO, HBrO and HIO, which is most acidic?

Arrange oxoacids of chlorine in the decreasing order of their acidic strength.

In an interhalogen compound XY_n, which halogen (X or Y) does exist in −1 oxidation state?

Among Cl₂, Br₂ and BrCl, which is most reactive?

What is the shape of ClF₃ molecule?

What type of hybridisation is involved in the formation of IF₅ molecule?

Name a pseudo halide ion and the corresponding pseudo halogen.

What is the value of C_p/C_v for a noble gas?

Among halogens and noble gases, which have higher atomic radii?

Are noble gases soluble in water?

What type of interaction is responsible for the solubility of a noble gas in water?

Name the chemist who prepared the first compound of xenon.

Write the structure of the first compound of xenon.

What is the geometry of XeF₂ molecule?

What type of hybridisation is involved in the formation of XeF₂ molecule?

What is the shape of the molecule of following xenon compound?

XeF₄

What is the shape of the molecule of following xenon compound?

XeF₆

What is the shape of the molecule of following xenon compound?

XeO₃

What is the shape of the molecule of following xenon compound?

XeOF₄

Name the type of hybridisation involved in the formation of following xenon compound.

XeF₄

What is the state of hybridisation of Xe in XeF₆?

Name the type of hybridisation involved in the formation of following xenon compound.

XeOF₄

What is the state of hybridisation of Xe in XeO₃?

Write the formula of xenic acid.

Which property is involved in the separation of noble gases by Dewar’s method?

What is the oxidation state of phosphorus in H₃PO₃?

What is the oxidation state of phosphorus in the following:

PCl₃

What is the oxidation state of phosphorus in the following:

Ca₃P₂

What is the oxidation state of phosphorus in the following:

Na₃PO₄

What is the oxidation state of phosphorus in the following:

POF₃

What is the oxidation state of S in the following compound?

PbS

What is the oxidation state of S in the following compound?

SO₂

What is the oxidation state of S in the following compound?

SF₆

What is the oxidation state of S in the following compound?

Na₂S₂O₃

What is the oxidation state of S in the following compound?

H₂SO₃

Find the oxidation state of the halogen in the following compound:

Cl₂O

Find the oxidation state of the halogen in the following compound:

ClO₂

Find the oxidation state of the halogen in the following compound:

KBrO₃

Find the oxidation state of the halogen in the following compound:

NaClO₄

Find the total number of lone pairs of electrons in N₂O₃.

Nitrogen exists as a diatomic molecule, while the other elements of group 15 exist as polyatomic molecules. Explain.

Why are the atomic radii of group 15 elements smaller than those of the corresponding elements of group 14?

Why are the melting points of antimony and bismuth lower than the expected values?

Why are the ionisation energies of group 15 elements much higher than those of the corresponding elements of group 14?

How does the metallic character vary on moving down the group 15? Give suitable explanation for the observed order.

The trinegative ions (M³⁻) are formed only by N and P among group 15 elements. Explain.

Why does the stability of +5 oxidation state decrease on moving down the group 15?

PCl₅ exists but NCl₅ does not. Explain.

Write the structure of white phosphorus.

Write the structure of red phosphorus.

Giving suitable reasons, arrange the hydrides (MH₃) of group 15 elements in the decreasing order of \[\ce{H - M - H}\] bond angle.

Discuss the structure of NH₃ and explain why does it possess a shorter bond angle than the expected one.

Why does PH₃ possess a smaller bond angle than that for NH₃?

Why does the basic strength of the hydrides of group 15 elements decrease on moving down the group?

Among NH₃, PH₃, AsH₃, SbH₃ and BiH₃, which does possess the highest reducing power and why?

Why does ammonia have a higher boiling point than that of phosphine?

Nitrogen does not form pentahalide.

Discuss the structure of PCl₅.

Complete and balance the following equation:

\[\ce{N2H4 + Cu^{2+} ->}\]

Complete and balance the following equation:

\[\ce{N2H4 + KIO3 ->}\]

Complete and balance the following equation: 

\[\ce{PCl3 + H2O ->}\] 

Complete and balance the following equation:

\[\ce{BiCl3 + H2O ->}\]

Complete and balance the following chemical equation:

\[\ce{Pb(NO3)2 ->[Heat]}\]

Complete and balance the following equation:

\[\ce{P2O5 + HNO3 ->}\]

Name the oxides of group 15 elements having the group element in +3 oxidation states.

Name the oxides of group 15 elements having the group element in +4 oxidation state.

Write the structures of different oxides of nitrogen.

Why do the oxides of phosphorus and other heavier elements of group 15 have cage structures?

Write the structure of phosphorus trioxide.

Write the structure of phosphorus pentoxide.

Write the structures of different oxides of nitrogen.

Write the formula, structure and basicity of the following oxoacid:

Hypophosphorus acid

Write the formula, structure and basicity of the following oxoacid:

Cyclometaphosphoric acid

Write the formula, structure and basicity of the following oxoacid:

Orthophosphoric acid

Write the formula, structure and basicity of the following oxoacid:

Pyrophosphoric acid

Why does orthophosphoric acid form three types of salts? Explain its ionisation behaviour.

How is orthophosphoric acid prepared from rock phosphate?

Mention important uses of orthophosphoric acid.

Why does nitrogen differ from other elements of its group in its chemical behaviour?

Why are group 16 elements called chalcogens?

Why is polonium called so?

Why does oxygen exist as a gas, whereas other elements of the group are solids at room temperature?

Write the structure of a sulphur molecule.

Why are the melting and boiling points of polonium lower than those of selenium?

Why is the first ionisation energy of oxygen lower than that of nitrogen?

Why is it difficult to ionise group 16 elements?

The electron affinity of oxygen is lower than that of sulphur. Explain.

Why does the tendency of group 16 elements to exist in −2 oxidation state decrease on moving down the group?

Oxygen usually exists in −2 oxidation state but it exhibits +2 state in OF₂. Explain.

Why do sulphur and other heavier elements of group 16 exhibit higher oxidation states?

Explain how sulphur exists in the +2 oxidation state.

Explain how sulphur exists in the +4 oxidation state.

Explain how sulphur exists in the +6 oxidation state.

How does the following property vary on moving down the group 16?

Atomic radii

How does the following property vary on moving down the group 16?

Metallic character

How does the following property vary on moving down the group 16?

Catenation

Discuss the important allotropic forms of sulphur.

Discuss the structure of H₂O molecule.

Why does \[\ce{H - M - H}\] bond angle in the hydrides of group 16 elements decrease on going down the group?

Water is a liquid while all other hydrides of group 16 elements are gases at room temperature. Explain.

Giving suitable reasons, arrange the hydrides of group 16 elements in the decreasing order of their thermal stability.

Giving suitable reasons, arrange the hydrides of group 16 elements in the increasing order of their acidic character.

Why does water not act as a reducing agent?

Why should the compound F₂O not be called as fluorine oxide? Write the correct representation and name of the compound.

How many types of halides are formed by sulphur? Write their general formulae and the oxidation states of sulphur in them.

Why is SF₆ used as a gaseous insulator in high voltage generators?

Discuss the structure of SF₆.

Discuss the structure:

SO₂

Discuss the structure:

SO₃

Write the structure of sulphur trioxide in the solid state.

Write the structure of selenium trioxide in the solid state.

Write the molecular formula and structure of sulphuric acid.

Write the formula and structure of the following oxoacid of sulphur:

Sulphurous acid

Write the formula and structure of the following oxoacid of sulphur:

Peroxodisulphuric acid

Write the molecular formula and structure of dithionic acid.

Why are the elements of group 17 called ‘halogens’?

Why does the state of agglomeration (the tendency of molecules to come closer) increase on moving down the group 17?

Why are the halogen atoms smallest in their respective periods?

Why does the density of halogens increase on moving down the group?

Why do melting and boiling points of halogens increase on moving down the group?

Why do halogens have very high ionisation energies?

Why do ionisation energies decrease in going from F to I in group 17?

Why do halogens possess very high values of electronegativity?

Arrange the halogens in the order of decreasing electronegativity.

Why do halogens have very high values of electron affinity?

The electron affinity of fluorine is unexpectedly lower than that of chlorine. Comment on the statement and explain.

Giving suitable reasons, arrange halogens in the decreasing order of electron affinity.

Why does iodine exhibit a slight metallic character?

Why does fluorine exhibit only −1 oxidation state in all of its compounds?

Taking the example of chlorine, show that all halogens (except fluorine) can exhibit +l, +3, +5 and +7 oxidation states.

Why does fluorine not exhibit higher oxidation states?

Explain the pale yellow colour of fluorine.

Explain violet colour of iodine.

How would you account for the very high reactivity of halogens?

Why do halogens act as oxidising agents?

A halogen of low atomic number can oxidise halide ions of higher atomic numbers. Comment on the statement and explain with suitable examples.

The following reaction is feasible or not feasible and why?

\[\ce{F2 + 2NaBr -> 2NaF + Br2}\]

The following reaction is feasible or not feasible and why?

\[\ce{Cl2 + 2NaF -> 2NaCl + F2}\]

The following reaction is feasible or not feasible and why?

\[\ce{Br2 + 2NaCl -> 2NaBr + Cl2}\]

The following reaction is feasible or not feasible and why?

\[\ce{I2 + 2NaCl -> 2NaI + Cl2}\]

The following reaction is feasible or not feasible and why?

\[\ce{Br2 + 2NaI -> 2NaBr + I2}\]

Giving suitable reasons, arrange metal halides \[\ce{(M - X)}\] in the decreasing order of their ionic character.

Hydrogen fluoride is a low boiling liquid, while all other hydrogen halides are gases at room temperature. Comment and explain.

Why does HF not show reducing properties, whereas other halogen halides do?

Why does the reducing power of hydrogen halides increase with increase in the atomic number of halogen?

Giving suitable reasons, arrange hydrogen halides in the increasing order of their acidic strength.

Write the structure of Cl₂O.

Write the structure of ClO₂.

Write the structure of Cl₂O₇.

What types of oxoacids are formed by halogens? Mention the oxidation states of halogens in them.

Write the formula and structure of hypofluorous acid.

Draw the structure of hypochlorous acid.

Complete and balance the following equation:

\[\ce{NaOH + Br2 ->[Cold]}\]

Complete and balance the following equation:

\[\ce{Na2O2 + ClO2 ->}\]

Complete and balance the following equation:

\[\ce{NaOH  + Cl2 ->[Hot]}\]

Complete and balance the following equation:

\[\ce{NaClO3 + H2O ->[Electrolysis]}\]

What is bleaching powder?

How is bleaching powder prepared from slaked lime?

Giving suitable explanation, arrange hypohalous acids of chlorine, bromine and iodine in the increasing order of their acid strength.

Giving suitable explanation, arrange oxoacids of chlorine in the increasing order of their acid strength.

What are interhalogen compounds?

How are interhalogen compounds classified?

Discuss the formation and structure of XF₃ (X = Cl, Br, I) molecule.

Write the structure of the following interhalogen compound:

ClF₅

Also mention the state of hybridisation of Cl atom present in it.

What is the hybridisation of iodine in IF₇? Give its structure.

Why does fluorine exhibit an anomalous behaviour as compared to the behaviour of other halogens?

What is basic iodine?

What are the evidences which support the existence of basic iodine?

What are pseudo halides and pseudo halogens and why are they called so? Give some examples.

The elements of group 18 should rightly be called as noble gases instead of inert gases. Comment on the statement and explain.

How would you justify the inclusion of group 18 in between group 17 and group 1 in the periodic table?

Write the names and electronic configurations of all the noble gases.

Why do noble gases exist as monoatomic molecules?

The atomic radii of noble gases are larger than those of the corresponding halogens. Explain.

Why are the melting and boiling points of noble gases much lower as compared to those of other substances of comparable molecular masses?

Why do noble gases have very high ionisation energies?

Giving suitable explanation, arrange noble gases in the increasing order of their solubility in water.

What type of interactions are responsible for the solubility of a noble gas in water? Explain.

Why does the solubility of noble gases in water increase with increase in the atomic number?

Among He, Ne, Ar, Kr and Xe, which gas is most easily liquefiable and why?

The electron gain enthalpy values of noble gases are large positive. Explain.

What type of compounds of noble gases were obtained prior to 1962?

When and how did the chemistry of noble gases begin?

Name the chemist who prepared the first compound of a noble gas.

Write the names and formulae of some important compounds of xenon.

Write the names and formulae of some important compounds of krypton.

Give the method of preparation of XeF₂.

Give the methods of preparation of the following compound:

XeOF₄

Give the methods of preparation of the following compound:

XeO₃

Complete the following equation: 

\[\ce{XeF2 + H2O ->}\]

Complete the equation:

\[\ce{XeF4 + H2O ->}\]

Complete the following reaction.

\[\ce{XeF6 + H2O ->}\]

Complete and balance the following equation:

\[\ce{XeF6 + NaF ->}\]

Complete and balance the following equation:

\[\ce{XeOF4 + H2O ->}\]

Complete and balance the following equation:

\[\ce{XeO3 + H2O ->}\]

Write the structures of fluorides of xenon.

Write the structure of XeOF₄. Mention the state of hybridisation of xenon atom in it.

Write the structure of XeO₃. Mention the state of hybridisation of xenon atom in it.

How would you account for the square pyramidal structure of XeOF₄ molecule? Explain the formation of the molecule.

Explain why aluminium, though an electropositive metal, finds extensive use as a structural material.

Discuss the pattern of variation in the oxidation state of the following:

Al to Tl

Discuss the pattern of variation in the oxidation state of the following:

Si to Pb

Discuss the pattern of variation in the oxidation states of the following:

P to Bi

What is the importance of ultrapure elemental silicon?

How is ultrapure elemental silicon obtained?

How far do you agree with the phenomenon concept of inert pair effect? Justify your answer.

Compare the structures of white phosphorus, P₄O₆ and P₄O₁₀.

Discuss the following property and its variation in the group 15 elements:

Atomic radii

How does the metallic character vary in group 15?

Discuss the following property and its variation in the group 15 elements:

Oxidation states

Discuss the following property and its variation in the group 15 elements:

Allotropy

Discuss the following property and its variation in the group 15 elements:

Catenation

What is the inert pair effect?

How does the inert pair effect affect the properties of group 15 elements?

Discuss the preparation of the hydrides of group 15 elements.

Discuss the structures of the hydrides of group 15 elements.

Discuss the important characteristics of the hydrides of group 15 elements.

What types of halides are formed by group 15 elements? Discuss their structures and important characteristics.

How are the different oxides of nitrogen prepared?

Discuss general characteristics of different oxides of nitrogen.

Write the structures of different oxides of nitrogen.

Give a brief account of the oxoacids of nitrogen and write their structures.

Give a brief account of the oxoacids of phosphorus and write their structures.

Mention some important methods of preparation of orthophosphoric acid.

Mention some properties of orthophosphoric acid.

In what ways does nitrogen differ from the other elements of group 15?

What are the causes for the anomalous behaviour of nitrogen?

Why are group 16 elements called chalcogens?

Discuss the important characteristics of group 16 elements.

Compare the elements of group 15 with those of group 16 in relation to the following property:

Atomic radii

Compare the elements of group 15 with those of group 16 in relation to the following property:

Ionisation energy

Compare the elements of group 15 with those of group 16 in relation to the following property:

Electronegativity

Compare the elements of group 15 with those of group 16 in relation to the following property:

Electron affinity

Compare the elements of group 15 with those of group 16 in relation to the following property:

Oxidation states

With suitable explanation, give a brief account of the oxidation states exhibited by the elements of group 16.

With suitable explanation, give a brief account of the allotropy exhibited by the elements of group 16.

Discuss the structures of the hydrides of group 16 elements.

Discuss the important characteristics of the hydrides of group 16 elements.

Give a brief account of the halides of group 16 elements.

Give a brief account of the oxides of group 16 elements.

Draw the structure of SF₄ molecule.

Discuss the structure of SF₆.

Discuss the structure:

SO₂

Discuss the structure:

SO₃

Give a brief account of the oxoacids of sulphur.

Give a brief account of the oxoacids of selenium.

Give a brief account of the oxoacids of tellurium.

Write the formula and structure of the following oxoacid of sulphur:

Sulphurous acid

Draw the structure of peroxymonosulphuric acid. 

Write the molecular formula and structure of thiosulphuric acid.

Write the molecular formula and structure of dithionic acid.

Discuss the anomalous behaviour of oxygen in relation to the properties of group 16 elements.

What are halogens and why are they called so?

Give the important physical characteristics of halogens.

Give the important chemical characteristics of halogens.

With suitable explanations, give a brief account of the oxidation states exhibited by halogens.

Why are halogens coloured?

Discuss the following property and its variation with reference to the elements of group 17:

Reactivity

Discuss the following property and its variation with reference to the elements of group 17:

Oxidising nature

Discuss the following property and its variation with reference to the elements of group 17:

Acidic nature of oxoacids

How are hydrogen halides prepared?

Discuss the structures of halides.

Mention some of the important characteristics with suitable explanation of hydrogen halides.

What type of oxoacids are formed by halogens?

Give a brief account of the preparation of the oxoacids of chlorine.

Give a brief account of the important properties of the oxoacids of chlorine.

Give a brief account of the acidic nature of the oxoacids of chlorine.

What are interhalogen compounds?

How are interhalogen compounds classified?

Write any two characteristics of interhalogen compounds.

Give a brief account of the structures of interhalogen compounds.

Write any two characteristics of interhalogen compounds.

Give a brief account of the structures of interhalogen compounds.

In what ways does fluorine differ from other halogens?

Discuss four points of anomalous behavior of fluorine.

What are noble gases and why are they called so?

Mention the important physical characteristics of noble gases.

Discuss the following property with reference to noble gases:

Chemical reactivity

Discuss the following property with reference to noble gases:

Atomicity

Discuss the following property with reference to noble gases:

Atomic radii

Discuss the following property with reference to noble gases:

Melting point

Discuss the following property with reference to noble gases:

Boiling point

Discuss the following property with reference to noble gases:

Ionisation energy

Discuss the following property with reference to noble gases:

Solubility in water

Discuss the following property with reference to noble gases:

Liquefaction tendency

Give a brief account of the chemistry of noble gases, with a special reference to the fluorides and oxyfluorides of xenon.

Give the methods of preparation of XeF₄.

Give the properties of the following compound:

XeF₄

Draw the structure of the following molecule: 

XeF₄

Give the methods of preparation of the following compound:

XeOF₄

Give the properties of the following compound:

XeOF₄

Write the structures of the following molecule: 

XeOF₄

Give the methods of preparation of the following compound:

XeF₆

Give the properties of the following compound:

XeF₆

Draw structures of XeF₆.

Give the methods of preparation of the following compound:

XeO₃

Give the properties of the following compound:

XeO₃

Draw the structure of XeO₃

What are the important ores of aluminium?

How is the metal extracted from the bauxite ore?

How does tin occur in nature?

Give a brief account of the extraction of tin from its ores.

Mention the important alloys of tin.

What are the important ores of lead?

How is the metal extracted from lead ores?

Mention some important properties of lead.

How is phosphine prepared in the laboratory?

Discuss important properties of phosphine.

Discuss the uses of phosphine.

Discuss the structure of phosphine.

Give the preparation of the following:

PCl₃

Give the properties of the following:

PCl₃

Give the uses of the following:

PCl₃

Give the preparation of the following:

PCl₅

Give the properties of the following:

PCl₅

Give the uses of the following:

PCl₅

How does sulphur occur in nature?

Give a brief account of the extraction of sulphur.

What is the effect of heat on sulphur?

How does phosphorus occur in nature?

Describe the preparation of white phosphorus.

Describe the preparation of red phosphorus.

Describe the manufacturing of H₂SO₄ by the contact process.

Give a brief account of the preparation of the oxoacids of chlorine.

Give a brief account of the important properties of the oxoacids of chlorine.

Give the important uses of oxoacids of chlorine.

How are noble gases isolated from air?

Describe the important uses of noble gases isolated from air.

Using VSEPR theory, predict the probable structure of \[\ce{SO^{2-}_3}\].

Using VSEPR theory, predict the probable structure of \[\ce{IF^-_6}\].

Using VSEPR theory, predict the probable structure of XeF₂.

Using VSEPR theory, predict the probable structure of \[\ce{ClO^-_4}\].

Using VSEPR theory, predict the probable structure of \[\ce{ICl^-_4}\].

Using VSEPR theory, predict the probable structure of \[\ce{IBr^-_2}\].

Describe the shape of the following species:

SiF₄

Describe the shape of the following species:

\[\ce{SiF^{2-}_6}\]

Describe the shape of the following species:

PF₅

The reaction of Xe and O₂F₂ gives a Xe compound P. The number of moles of HF produced by the complete hydrolysis of 1 mol of P is ______. (nearest integer)

NH₃ has much higher boiling point than PH₃, because ______.

Which of the following oxides of nitrogen is the anhydride of nitrous acid?

PCl₅ exists but NCl₅ does not because ______.

Which hydride is most stable?

The largest bond angle is in ______.

NH₃ molecule can enter into complex formation through ______.

NF₃ is less polar than NH₃ because ______.

The oxoacid of phosphorus in which phosphorus has the lowest oxidation state is ______.

Which of the following nitrogen halides is most stable?

A white precipitate is obtained on hydrolysis of ______.

Structure of SF₄ is ______.

Which one has the highest bond energy?

H₂S is more acidic than H₂O although sulphur is less electronegative than oxygen. This is because ______.

Which has sp² hybridisation?

The maximum covalency of sulphur is ______.

Oxygen exhibits −1 oxidation state in ______.

The hybridisation state of S in SF₆ is ______.

Which one of the following has lowest boiling point?

Ozone is ______.

Which one is the strongest reducing agent?

Which one is the strongest oxidising agent?

Among the following, the pseudo halide is ______.

Fluorine can exist in the oxidation states ______.

The most powerful oxidising agent is ______.

Iodine can form the ions ______.

The following acids have been arranged in the order of decreasing acid strength.

CIOH (I) BrOH (II) IOH (III)

Identify the correct order.

If one litre of air is passed repeatedly on hot copper and hot magnesium till no further decrease in volume takes place, the volume of residual gas would be about ______.

Which one of the following fluorides does not exist?

The structure of XeF₆ is ______.

The first noble gas compound obtained was ______.

XeF₆ on complete hydrolysis gives ______.

Geometry of XeOF₄ molecule is ______.

The ionic radii (in Å) of N³⁻, O²⁻ and F⁻ are respectively ______.

Which among the following is the most reactive?

Match the catalysts to the correct processes:

Which one has the highest boiling point?

Assertion: Nitrogen and oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen.

Reason: The reaction between nitrogen and oxygen requires high temperature.

The species in which the N atom is in a state of sp hybridization is ______.

The reaction of zinc with dilute and concentrated nitric acid, respectively, produces ______.

The pair in which phosphorous atoms have a formal oxidation state of +3 is ______.

The reagent(s) that can selectively precipitate S²⁻ from a mixture of S²⁻ and \[\ce{SO^{2-}_4}\] in aqueous solution is (are) ______.

Consider the molecules CH₄, NH₃ and H₂O. Which of the given statement is false?

Among the following the correct order of acidity is:

When copper is heated with conc. HNO₃, it produces ______.

Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules?

The product obtained as a result of a reaction of nitrogen with CaC₂ is ______.

Match the compounds given in column I with the hybridisation and shape given in column II and mark the correct option.

Which is the correct statement for the given acids?

The species, having bond angles of 120° is ______.

In which of the pair of ions, both species contain S-S bond?

Match the interhalogen compounds of column I with the geometry in column II and assign the correct code.

Name the gas that can readily decolourises acidified KMnO₄ solution.

Which of the following species is not paramagnetic?

The products obtained when chlorine gas reacts with cold and dilute aqueous NaOH are ______.

The compound that does not produce nitrogen gas by the thermal decomposition is:

When Metal ‘M’ is treated with NaOH, a white gelatinous precipitate ‘X’ is obtained, which is soluble in excess of NaOH. Compound ‘X’ when heated strongly gives an oxide which is used in chromatography as an adsorbent. The metal ‘M’ is ______.

The correct order of N-compounds in its decreasing order of oxidation states is ______.

Which of the following statements is not true for halogens?

In the structure of CIF₃, the number of lone pair of electrons on central atom ‘Cl’ is ______.

Which oxide of nitrogen is not a common pollutant introduced into the atmosphere both due to natural and human activity?

The oxoacid of sulphur that does not contain bond between sulphur atoms is ______.

The noble gas that does not occur in the atmosphere is:

The number of pentagons in C₆₀ and trigons (triangles) in white phosphorus, respectively, are:

An organic compound ‘A’ is oxidized with Na₂O₂ followed by boiling with HNO₃. The resultant solution is then treated with ammonium molybdate to yield a yellow precipitate. Based on above observation, the element present in the given compound is ______.

The group number, number of valence electrons, and valency of an element with atomic number 15, respectively, are ______.

Which of the following is paramagnetic?

Identify the correct formula of 'oleum' from the following:

Which of the following cannot act both as Bronsted acid and as Bronsted base?

The correct structure of tribromooctaoxide is:

The number of moles of hydrogen molecules required to produce 20 moles of ammonia through Haber’s process is ______.

Identify the incorrect statement related to PCl₅ from the following:

Match the xenon compounds in Column-I with its structure in Column-II and assign the correct code:

Which is the correct thermal stability order for H₂E (E = 0, S, Se, Te and Po)?

Match the following.

Which of the following is the correct option?

Which of the following oxoacid of sulphur has -O-O- linkage?

Match the following:

Which of the following is correct option?

While titrating dilute HCl solution with aqueous NaOH, which of the following will not be required?

The statement that is not true about ozone is:

In a molecule of pyrophosphoric acid, the number of P-OH, P=O and P-O-P bonds/moiety(ies) respectively are ______.

If the boiling point of H₂O is 373 K, the boiling point of H₂S will be ______.

Aqua regia is used for dissolving noble metals (Au, Pt, etc.). The gas evolved in this process is ______.

The reacition in which the hybridisation of the underlined atom is affected is:

The structure of PCl₅ in the solid state is ______.

Noble gases are named because of their inertness towards reactivity. Identify an incorrect statement about them.

Match List-I with List-II.

Choose the correct answer from the options given below.

In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it?

Statement I: Acid strength increases in the order given as HF << HCl << HBr << HI.

Statement II: As the size of the elements F, Cl, Br, and I increase down the group, the bond strength of HF, HCl, HBr and HI decreases and so the acid strength increases.

In the light of the above statements, choose the correct answer from the options given below.

Match List-I with List-II.

Choose the correct answer from the options given below

A group 15 element, which is a metal and forms a hydride with strongest reducing power among group 15 hydrides. The element is ______.

The set that represents the pair of neutral oxides of nitrogen is ______.

The oxidation states of nitrogen in NO, NO₂, N₂O and \[\ce{NO^-_3}\] are in the order of:

Fex₂ and Fey₃ are known when x and y are ______.

The correct statement(s) related to oxoacids of phosphorous is (are):

The number of ioinisable hydrogens present in the product obtained from a reaction of phosphorus trichloride and phosphoric acid is ______.

Statement I: The boiling points of the following hydrides of group 16 elements increases in the order:

H₂O < H₂S < H₂Se < H₂Te

Statement II: The boiling points of these hydrides increase with increase in molar mass.

In the light of above statements, choose the most appropriate answer from the options given below:

Amongst the following which one will have maximum lone pair-lone pair electron repulsions?

Heating white phosphorus with conc. NaOH solution gives mainly ______.

Match List-I with List-II by matching the gas evolved during each reaction.

Choose the correct answer from the options given below:

White phosphorus reacts with thionyl chloride to give ______.

Concentrated HNO₃ reacts with iodine to give ______.

The treatment of galena with HNO₃ produces a gas that is ______.

The compound(s) which react(s) with NH₃ to give boron nitride (BN) is (are):

The correct option(s) related to the extraction of iron from its ore in the blast furnace operating in the temperature range 900-1500 K is (are):

The elements of group 15 possess a ______ np subshell.

On moving down the group 15, metallic character ______.

Nitrogen exhibits all oxidation states from ______ to ______.

PH₃ molecule is formed by ______ hybridisation and has H-P-H bond angle equal to ______.

Among the hydrides of group 15 elements, ______ is most stable and most basic.

Among the hydrides of group 15 elements, the strongest reducing agent is ______.

Hydrazine burns in oxygen to give ______ and ______.

The trihalides of group 15 elements are predominantly ______ and have ______ structures.

PCl₅ is formed by ______ hybridisation and is ______ in shape.

Sb₄O₆ is ______ in nature, while Bi₂O₃ is ______.

Hyponitrous acid has the formula ______ and its basicity is ______.

The oxidation states of phosphorus in hypophosphorus acid and pyrophosphoric acid are ______ and ______ respectively.

Orthophosphoric acid is a ______ basic acid and forms ______ types of salts.

The density of group 16 elements ______ on moving down the group.

The first ionisation energy of S is ______ than that of P.

The electron affinity of oxygen is ______ than that of S.

The allotropic forms of sulphur can be grouped into ______ classes.

The low volatility of water as compared to the other hydrides of group 16 elements is due to the ______ of H₂O molecules through ______.