Chapter 8, Problem 8C.5E

(a)

Interpretation Introduction

Interpretation:

The chemical equation for the reaction between sodium and oxygen has to be written.

Answer to Problem 8C.5E

The chemical equation for the reaction between sodium and oxygen is,

Sodium Peroxide:

  ${\text{2Na}}_{\left(\text{s}\right)}{\text{+O}}_{\text{2(g)}}\stackrel{}{\to }{\text{Na}}_{\text{2}}{\text{O}}_{\text{2(s)}}$

Sodium Superoxide:

  ${\text{4Na}}_{\left(\text{s}\right)}{\text{+O}}_{\text{2(g)}}\stackrel{}{\to }{\text{2Na}}_{\text{2}}{\text{O}}_{\text{(s)}}$

Explanation of Solution

Sodium reacts with oxygen to form sodium peroxide and sodium superoxide respectively.  The chemical equation for the reaction between sodium and oxygen is,

Sodium Peroxide:

  ${\text{2Na}}_{\left(\text{s}\right)}{\text{+O}}_{\text{2(g)}}\stackrel{}{\to }{\text{Na}}_{\text{2}}{\text{O}}_{\text{2(s)}}$

Sodium Superoxide:

  ${\text{4Na}}_{\left(\text{s}\right)}{\text{+O}}_{\text{2(g)}}\stackrel{}{\to }{\text{2Na}}_{\text{2}}{\text{O}}_{\text{(s)}}$

(b)

Interpretation Introduction

Interpretation:

The chemical equation for the reaction between lithium and nitrogen has to be written.

Answer to Problem 8C.5E

The chemical equation for the reaction between lithium and nitrogen is,

  ${\text{6Li}}_{\left(\text{s}\right)}{\text{+N}}_{\text{2(g)}}\stackrel{}{\to }{\text{2Li}}_{\text{3}}{\text{N}}_{\left(\text{s}\right)}$

Explanation of Solution

Lithium reacts with nitrogen to form Lithium nitride.  The chemical equation for the reaction between lithium and nitrogen is,

  ${\text{Li}}_{\left(\text{s}\right)}{\text{+N}}_{\text{2(g)}}\stackrel{}{\to }{\text{Li}}_{\text{3}}{\text{N}}_{\left(\text{s}\right)}$

Six moles of lithium are required in the reactant side and two moles of lithium nitride are required in the product side to make the equation a balanced one.  The balanced chemical equation for the reaction between lithium and nitrogen is,

  ${\text{6Li}}_{\left(\text{s}\right)}{\text{+N}}_{\text{2(g)}}\stackrel{}{\to }{\text{2Li}}_{\text{3}}{\text{N}}_{\left(\text{s}\right)}$

(c)

Interpretation Introduction

Interpretation:

The chemical equation for the reaction between sodium and water has to be written.

Answer to Problem 8C.5E

The chemical equation for the reaction between sodium and water is,

  ${\text{2Na}}_{\left(\text{s}\right)}{\text{+2H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\to }{\text{2NaOH}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2(g)}}$

Explanation of Solution

Sodium reacts with water to form sodium hydroxide with the evolution of hydrogen gas.  The chemical reaction is,

  ${\text{Na}}_{\left(\text{s}\right)}{\text{+H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\to }{\text{NaOH}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2(g)}}$

Two moles of sodium and two moles of water are required in the reactant side, and two moles of sodium hydroxide are required in the product side to make the equation a balanced one.  The balanced chemical equation for the reaction between sodium and water is,

  ${\text{2Na}}_{\left(\text{s}\right)}{\text{+2H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\to }{\text{2NaOH}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2(g)}}$

(d)

Interpretation Introduction

Interpretation:

The chemical equation for the reaction between potassium superoxide and water has to be written.

Answer to Problem 8C.5E

The chemical equation for the reaction between potassium superoxide and water is,

  ${\text{4KO}}_{\text{2(s)}}{\text{+2H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\to }{\text{4KOH}}_{\left(\text{aq}\right)}{\text{+3O}}_{\text{2(g)}}$

Explanation of Solution

Potassium superoxide reacts with water to form potassium hydroxide with the evolution of oxygen gas.  The chemical reaction is,

  ${\text{KO}}_{\text{2(s)}}{\text{+2H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\to }{\text{KOH}}_{\left(\text{aq}\right)}{\text{+O}}_{\text{2(g)}}$

Four moles of potassium superoxide and two moles of water are required in the reactant side, four moles of sodium hydroxide and three moles of oxygen are required in the product side to make the equation a balanced one.  The balanced chemical equation for the reaction between potassium superoxide and water is,

  ${\text{4KO}}_{\text{2(s)}}{\text{+2H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\to }{\text{4KOH}}_{\left(\text{aq}\right)}{\text{+3O}}_{\text{2(g)}}$