Chapter 21, Problem 48PS

(a)

Interpretation Introduction

Interpretation:

The balanced chemical equation for the reaction of aluminium and water has to be given.

Concept introduction:

• Balanced chemical equation of a reaction is written according to law of conservation of mass.
• Stoichiometry of a chemical reaction is the relation between reactants and products of the reaction and it is represented by the coefficients used for the reactants and products involved in the chemical equation.

(b)

Interpretation Introduction

Interpretation:

The standard free energy change, standard enthalpy change and standard entropy change for the given reaction has to be given.

Concept introduction:

The Gibbs free energy or the free energy change is a thermodynamic quantity represented by $\Delta G^{\circ }$. It is related to entropy and entropy by the following expression,

$\Delta G^{\circ }=\Delta H^{\circ }-T\Delta S^{\circ }$

Here, $\Delta H^{\circ }$ is the change in enthalpy and $\Delta S^{\circ }$ is the change in entropy.

(c)

Interpretation Introduction

Interpretation:

Aluminum metal is unaffected by water. The reason behind this has to be explained.

Concept introduction:

Aluminium has a chemical property that, it reacts with oxygen to form an oxide. The aluminium oxide is strong and it is unaffected by water.

The reaction occurred in this process is,

$Al+2O\underset{}{\to }Al{O}_2$