Calculate the mass and volume of oxygen at S.T.P., which will be evolved on electrolysis of 1 mole (18g) of water

1.56 g of sodium peroxide reacts with water according to the following equation:

2Na₂O₂ + 2H₂O ⟶ 4NaOH + O₂

Calculate:

(a) mass of sodium hydroxide formed,

(b) volume of oxygen liberated at S.T.P.

(c) mass of oxygen liberated.

Aluminium carbide reacts with water according to the following equation.

Al₄C₃ + 12H₂O ⟶ 3CH₄ + 4Al(OH)₃

(a) What mass of aluminium hydroxide is formed from 12g of aluminium carbide?

(b) What volume of methane is obtained from 12g of aluminium carbide?

MnO₂ + 4HCl ⟶ MnCl₂ + 2H₂O + Cl₂

0.02 moles of pure MnO₂ is heated strongly with conc. HCl. Calculate:

(a) mass of MnO₂ used

(b) moles of salt formed,

(c) mass of salt formed,

(d) moles of chlorine gas formed,

(e) mass of chlorine gas formed,

(f) volume of chlorine gas formed at S.T.P.,

(g) moles of acid required,

(h) Mass of acid required.