Chapter 8.3, Problem 7RQ

(a)

Interpretation Introduction

Interpretation :

The reaction of aluminium and oxygen must be balanced and classified in different way.

Concept Introduction :

4 Moles of aluminium and 3 moles of oxygen react to produce 2 moles of aluminium oxide.

Answer to Problem 7RQ

  ${\text{2Al(s)+3O}}_{\text{2}}\text{(g)}\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\text{(s)}\text{.}$

This reaction can be classified as combination reaction, combustion reaction and oxidation-reduction reaction.

Explanation of Solution

In the balanced equation there are 2 atoms of Al and 6 atoms of O in both the sides.

This is a combination reaction as two reactant combines to produce a single product.

This is a combustion reaction as Al is combusted in presence of O.

This is an oxidation-reduction reaction as Al (oxidation number 0) is oxidized to Al₂O₃ (oxidation number +3) and O (oxidation number 0) is reduced to Al₂O₃ (oxidation number -2).

b)

Interpretation Introduction

Interpretation :

The reaction of barium hydroxide and sulfuric acid must be balanced and classified in different ways.

Concept Introduction :

1 Mole of each of barium hydroxide and sulfuric acid react to produce 1 mole of barium sulfate and 2 moles of water.

Answer to Problem 7RQ

  ${\text{Ba(OH)}}_2{\text{(aq)+H}}_{\text{2}}{\text{SO}}_{\text{4}}\text{(aq)}\to {\text{BaSO}}_{\text{4}}{\text{(s)+2H}}_2\text{O(aq)}\text{.}$

This reaction can be classified as double decomposition reaction and neutralization reaction.

Explanation of Solution

In the balanced equation there are 1 atoms of Ba, 6 atoms of O and 4 atoms of H in both the sides.

This is a double displacement or precipitation reaction as two soluble substances produce one insoluble solid or precipitate.

This is a neutralization reaction as an acid reacts with a base to produce salt and water.

c)

Interpretation Introduction

Interpretation :

The decomposition reaction of H₂O₂ must be balanced and classified in different ways.

Concept Introduction :

2 Moles of H₂O₂ decompose to produce 2 moles of H₂O and 1 mole of O₂.

Answer to Problem 7RQ

  ${\text{2H}}_{\text{2}}{\text{O}}_{\text{2}}\text{(aq)}\to {\text{2H}}_{\text{2}}\text{O(l)}+O_2(g)$

This reaction can be classified as decomposition reaction and oxidation-reduction reaction.

Explanation of Solution

In the balanced equation there are 4 atoms of H and 4 atoms of O in both the sides.

This is a decomposition reaction as a single reactant produces two products.

This is an oxidation-reduction reaction as O of H2O2 (oxidation number -1) is oxidized to O₂ (oxidation number 0) and reduced to H₂O (oxidation number of O is -2).