Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

In a compound, nitrogen atoms (N) make cubic close packed lattice and metal atoms (M) occupy one-third of the tetrahedral voids present. Determine the formula of the compound formed by M and N?

Show that in a cubic close packed structure, eight tetrahedral voids are present per unit cell.

On the basis of information given below mark the correct option.

(A) In bromoethane and chloroethane mixture intermolecular interactions of A–A and B–B type are nearly same as A–B type interactions.

(B) In ethanol and acetone mixture A–A or B–B type intermolecular interactions are stronger than A–B type interactions.

(C) In chloroform and acetone mixture A–A or B–B type intermolecular interactions are weaker than A–B type interactions.

On the basis of information given below mark the correct option.
On adding acetone to methanol some of the hydrogen bonds between methanol molecules break.

Using Raoult’s law explain how the total vapour pressure over the solution is related to mole fraction of components in the following solutions.

\[\ce{CHCl3(l) and CH2Cl2(l)}\]

Using Raoult’s law explain how the total vapour pressure over the solution is related to mole fraction of components in the following solutions.

\[\ce{NaCl(s) and H2O(l)}\]

Which reagent will you use for the following reaction?

\[\ce{CH3CH2CH2CH3 -> CH3CH2CH2CH2Cl + CH3CH2CHClCH3}\]

A primary alkyl halide would prefer to undergo ______.

Which of the statements are correct about above reaction?

(i) (a) and (e) both are nucleophiles.

(ii) In (c) carbon atom is sp³ hybridised.

(iii) In (c) carbon atom is sp² hybridised.

(iv) (a) and (e) both are electrophiles.

Which of the following statements are correct about this reaction?

(i) The given reaction follows S_N2 mechanism.

(ii) (b) and (d) have opposite configuration.

(iii) (b) and (d) have same configuration.

(iv) The given reaction follows S_N1 mechanism.

Which of the following statements are correct about the kinetics of this reaction?

(i) The rate of reaction depends on the concentration of only (b).

(ii) The rate of reaction depends on concentration of both (a) and (b).

(iii) Molecularity of reaction is one.

(iv) Molecularity of reaction is two.

Ethylene chloride and ethylidene chloride are isomers. Identify the correct statements.

(i) Both the compounds form same product on treatment with alcoholic KOH.

(ii) Both the compounds form same product on treatment with aq.NaOH.

(iii) Both the compounds form same product on reduction.

(iv) Both the compounds are optically active.

Which of the compounds will react faster in S_N1 reaction with the ^–OH ion?

\[\ce{CH3-CH2-Cl}\] or \[\ce{C6H5-CH2-Cl}\]

Compound ‘A’ with molecular formula \[\ce{C4H9Br}\] is treated with aq. \[\ce{KOH}\] solution. The rate of this reaction depends upon the concentration of the compound ‘A’ only. When another optically active isomer ‘B’ of this compound was treated with aq. \[\ce{KOH}\] solution, the rate of reaction was found to be dependent on concentration of compound and \[\ce{KOH}\] both.

(i) Write down the structural formula of both compounds ‘A’ and ‘B’.

(ii) Out of these two compounds, which one will be converted to the product with inverted configuration.

Write the structures and names of the compounds formed when compound ‘A’ with molecular formula, \[\ce{C7H8}\] is treated with \[\ce{Cl2}\] in the presence of \[\ce{FeCl3}\].

How do polar solvents help in the first step in S_N1 mechanism?

Elimination reactions (especially β-elimination) are as common as the nucleophilic substitution reaction in case of alkyl halides. Specify the reagents used in both cases.

Aryl halides are extremely less reactive towards nucleophilic substitution. Predict and explain the order of reactivity of the following compounds towards nucleophilic substitution:

(I)
(II)
(III)

Cyanide ion acts as an ambident nucleophile. From which end it acts as a stronger nucleophile in aqueous medium? Give reason for your answer.

Match the reactions given in Column I with the types of reactions given in Column II.

	Column I	Column II
(i)		(a) Nucleophilic aromatic substitution
(ii)	\[\begin{array}{cc} \ce{CH3 - CH = CH2 + HBr -> CH3 - CH - CH3}\\ \phantom{............................}|\phantom{}\\ \phantom{.............................}\ce{Br}\phantom{} \end{array}\]	(b) Electrophilic aromatic substitution
(iii)		(c) Saytzeff elimination
(iv)		(d) Electrophilic addition
(v)	\[\begin{array}{cc} \ce{CH3  CH2 CH CH3 ->[alc.KOH] CH3  CH = CH CH3}\\ \phantom{}|\phantom{..........................}\\ \phantom{}\ce{Br}\phantom{........................} \end{array}\]	(e) Nucleophilic substitution (SN1)