Balbharati solutions for सायन्स अँड टेक्नॉलोजी पार्ट १ [इंग्रजी] इयत्ता १० महाराष्ट्र राज्य मंडळ chapter 3 - Chemical reactions and equations [Latest edition]

What are the types of molecules of elements?

What are the types of molecules of compounds?

What is meant by the valency of an element?

What is the requirement for writing molecular formulae of different compounds? How are the molecular formulae of the compounds written?

Identify physical and chemical changes from the phenomena given in the following table.

What are the other uses of silver nitrate in everyday life?

Complete the table on the basis of the given equation.

\[\ce{AgNO3_{(aq)} + NaCl_{(aq)} -> \underset{(white)}{AgCl↓} + NaNO3_{(aq)}}\]

Identify the reactants and products of the given equation.

\[\ce{Vegetable oil (l) + H2(g) ->[60^° C][Ni Catalyst] Vanaspathi ghee (s)}\]

Write down the steps in balancing the equation \[\ce{N2(g) + H2(g) <=> NH3(g)}\]

Write down a balanced chemical equation for the following reaction:

Calcium chloride + Sulfuric acid → Calcium sulphate + hydrogen chloride

Write down the physical state of reactants and products in following reaction.

\[\ce{SO2 + 2H2S -> 3S + 2H2O}\]

Write down the physical state of reactants and products in following reaction.

\[\ce{2Ag + 2HCl -> 2AgCl + H2}\]

\[\ce{\underset{Ammonia}{NH3(g)} + \underset{Hydrogen chloride}{HCl(g)} -> \underset{Ammonium chloride}{NH4Cl(s)}}\]

\[\ce{2Mg + O2 -> 2MgO}\]

\[\ce{\underset{Calcium oxide}{CaO} + \underset{water}{H2O} -> \underset{Calcium hydroxide}{Ca(OH)2} + Heat}\]

1. What is the number of reactants in each of the above reactions?
2. What is the number of molecules of reactants taking part in the above reactions?
3. How many products are formed in each of the above reactions?

Is it possible to produce hydrogen by decomposition of water by means of heat, electricity or light?

Complete the following reaction and give name of products:

CuSO₄(aq) + Fe_(s) → ______ + ______

Complete the following reaction and give name of products:

CuSO₄ (aq) + Pb(s) → ............. + .............

What is the difference in the process of dissolution and a chemical reaction?

Does a new substance form when a solute dissolves in a solvent?

Which is the oxidant used for purification of drinking water?

Why is potassium permanganate used during cleaning water tanks?

Some more examples of redox reaction are as follows. Identify the reductants and oxidants from them.

\[\ce{2H2S + SO2 -> 3S↓ + 2H2O}\]

\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2↑}\]

If oxidation means losing electrons, what is meant by reduction?

Write the reaction of formation of Fe²⁺ by reduction Fe³⁺ by making use of the symbol (e^-).

The luster of the surface of the aluminium utensils in the house is lost after a few days. Why does this happen?

How are the blackened silver utensils and patinated (greenish) brass utensils cleaned?

Choose the correct option from the bracket and explain the statement giving reason.

(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)

To prevent rusting, a layer of ______ metal is applied on iron sheets.

Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition) 

The conversion of ferrous sulphate to ferric sulphate is ______ reaction. 

When electric current is passed through acidulated water ______ of water takes place.

Choose the correct option from the bracket and explain the statement giving a reason.

(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition) 

Addition of an aqueous solution of ZnSO₄ to an aqueous solution of BaCl₂ is an example of ______ reaction.

What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.

How can the rate of the chemical reaction, namely, decomposition of hydrogen peroxide be increased?

Explain the term reactant and product giving examples. 

Explain the types of reaction with reference to oxygen and hydrogen. Illustratre with examples.

Write the answer to the following.

Explain the similarity in two events, namely adding NaOH to water and adding CaO to water.

Write the answer to the following.

Explain the difference in two events, namely adding NaOH to water and adding CaO to water.

Explain the term with examples.

Endothermic reaction  

Explain the  terms with examples.

 Combination reaction

Explain the terms with examples.

Balanced equation

Explain the terms with examples.

Displacement reaction

Give a scientific reason.

When the gas formed on heating limestone is passed through freshly prepared lime water, the lime water turns milky.

Give scientific reason.

It takes time for pieces of Shahabad tile to disappear in HCl, but its powder disappears rapidly.

Give scientific reason.

While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.

Give scientific reason.

It is reccommended to use air tight container for storing oil for long time.

Observe the following picture a write down the chemical reaction with the explanation.

Identify from the reaction the reactants that undergo oxidation and reduction.
Fe + S → FeS

Identify from the following reaction the reactants that undergo oxidation and reduction.

\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]

Identify from the reaction the reactants that undergo oxidation and reduction.

2Mg + O₂ → 2MgO

Identify from the reaction the reactants that undergo oxidation and reduction.

\[\ce{NiO + H2 -> Ni + H2O}\]

Balance the equation stepwise.
H₂S₂O₇(l) + H₂O(l) → H₂SO₄(l)

Balance the equation stepwise.

 SO₂(g) + H₂S(aq) → S(s) + H₂O(l) 

Balance the equation stepwise.

 Ag(s) + HCl(aq) → AgCl ↓+ H₂ ↑ 

Balance the equation stepwise.

NaOH(aq) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂O(l)

Identify the endothermic and exothermic reaction.

HCl + NaOH → NaCl + H₂O + heat

Identify the endothermic and exothermic reaction.

\[\ce{2KClO_{3(s)}->[\Delta] 2KCl_{(s)} + 3O2}\]

Identify the endothermic and exothermic reaction.

\[\ce{CaO + H2O -> Ca(OH)2 + Heat}\]

Identify the endothermic and exothermic reaction.

\[\ce{CaCO_{3(s)}->[\Delta] CaO_{(s)} + CO2}\]

Match the column in the following table.