Study the diagram given below and identify the gas formed in the reaction.

1. Carbon di-oxide which extinguishes the burning candle.
2. Oxygen due to which the candle burns more brightly.
3. Sulphur dioxide which produces a suffocating smell.
4. Hydrogen which while burning produces a popping sound.

Sodium reacts with water to form sodium hydroxide and hydrogen gas. The balanced equation which represents the above reaction is

1. Na(s) + 2H₂O(l) ⟶ 2NaOH(aq) + 2H₂(g)
2. 2Na(s) + 2H₂O(l) ⟶ 2NaOH(aq) + H₂(g)
3. 2Na(s) + 2H₂O(l) ⟶ NaOH(aq) + 2H₂(g)
4. 2Na(s) + H₂O(l) ⟶ 2NaOH(aq) + 2H₂(g)

C₆H₁₂O₆ (aq) + 6O₂ (aq) ⟶ 6CO₂ (aq) + 6H₂O (l)

The above reaction is a/an

1. displacement reaction
2. endothermic reaction
3. exothermic reaction
4. neutralisation reaction

Which of the following statements about the reaction given below are correct?

MnO₂ + 4HCl ⟶ MnCl₂ + 2H₂O + Cl₂

(i) HCl is oxidized to Cl₂

(ii) MnO₂ is reduced to MnCl₂

(iii) MnCl₂ acts as an oxidizing agent

(iv) HCl acts as on oxidizing agent

1. (ii), (iii) and (iv)
2. (i), (ii) and (iii)
3. (i) and (ii) only
4. (iii) and (iv) only