Chemical Reactions and Equations NCERT Solution, study material, CBSE Notes

NCERT Solution: Chemical Reactions and Equations

(d) Ethene is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light.

C₂H₄ + 3O₂ → 2CO₂ + H₂O + Heat

This is combustion reaction.

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.(a) Thermite reaction, iron (III) oxide reacts with aluminium and gives molten iron and aluminium oxide.

Fe₂O₃ + 2Al -> 2Fe + Al₂ + Heat + light

This is displacement reaction.

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.(b) Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride

3Mg + N₂ -> Mg₃N₂

This is combination reaction.

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.(c) Chlorine gas is passed in an aqueous potassium iodide solution to form potassium chloride solution and solid iodine.

Ans. KI + Cl₂ -> 2KCl + I₂

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.(d) Ethanol is burnt in air to form carbon dioxide, water and releases heat.

C₂H₅OH +3O₂ → CO₂ + 3H₂O + Heat

This is redox reaction.

Complete the missing components/ variables given as x and y in the following reactions

(a) Pb(NO₃)₂(aq) + 2KI(aq) -> PbI₂(x) + 2KNO₃(y)

Ans. x →s, y →aq

(b) Cu(s) + AgNO(aq) → Cu(NO₃)₂ (aq) + x

Ans. x → Ag

Ans. x →aq, y →g

(d) CaCO₃ x → CaO (s) + CO₂ (g)

Ans. x → heat

Which among the following changes are exothermic or endothermic in nature?

(a) Decomposition of ferrous sulphate
Ans. Endothermic
(b) Dilution of sulphuric acid
Ans. Exothermic
(c) Dissolution of sodium hydroxide in water
Ans. Exothermic
(d) Dissolution of ammonium chloride in water
Ans. Endothermic

Identify the reducing agent in the following reactions

(a) 4NH₃ + 5O₂ -> 4NO + 6H₂O
Ans. Ammonia (NH3)

(b) H₂O + F₂ -> HF + HOF
Ans. Fluorine

(d) 2H₂ + O₂ -> 2H₂O
Ans. Hydrogen