Chapter 21, Problem 21.94QP

(a)

Interpretation Introduction

Interpretation:

The complete balanced equation for the given incomplete reaction has to be written.

Concept Introduction:

Balanced Chemical equation:

A balanced chemical equation is an equation which contains same elements in same number on both the sides (reactant and product side) of the chemical equation thereby obeying the law of conservation of mass.

Answer to Problem 21.94QP

${\text{2LiHCO}}_{\text{3}}{}_{\left(\text{s}\right)}\left(\text{heat}\right)\stackrel{}{\to }{\text{Li}}_{\text{2}}{\text{CO}}_{\text{3}}{}_{\left(\text{s}\right)}{\text{ + CO}}_{\text{2}}{}_{\left(\text{g}\right)}{\text{ + H}}_{\text{2}}{\text{O}}_{\left(\text{g}\right)}$

Explanation of Solution

To Write: The complete balanced equation for the given incomplete reaction.

Lithium bicarbonate undergoes decomposition while heating and gives lithium carbonate, water and carbon dioxide.

${\text{LiHCO}}_{\text{3}}{}_{\left(\text{s}\right)}\left(\text{heat}\right)\stackrel{}{\to }{\text{Li}}_{\text{2}}{\text{CO}}_{\text{3}}{}_{\left(\text{s}\right)}{\text{ + CO}}_{\text{2}}{}_{\left(\text{g}\right)}{\text{ + H}}_{\text{2}}{\text{O}}_{\left(\text{g}\right)}$

The balanced equation is given as follows,

${\text{2LiHCO}}_{\text{3}}{}_{\left(\text{s}\right)}\left(\text{heat}\right)\stackrel{}{\to }{\text{Li}}_{\text{2}}{\text{CO}}_{\text{3}}{}_{\left(\text{s}\right)}{\text{ + CO}}_{\text{2}}{}_{\left(\text{g}\right)}{\text{ + H}}_{\text{2}}{\text{O}}_{\left(\text{g}\right)}$

Lithium carbonate has two lithium atoms. Thus, lithium bicarbonate on reactants side gets coefficient two and other compounds does not need any coefficient.  Now in both sides the elements are balanced.

(b)

Interpretation Introduction

Interpretation:

The complete balanced equation for the given incomplete reaction has to be written.

Concept Introduction:

Balanced Chemical equation:

A balanced chemical equation is an equation which contains same elements in same number on both the sides (reactant and product side) of the chemical equation thereby obeying the law of conservation of mass.

Answer to Problem 21.94QP

${\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}{}_{\left(\text{aq}\right)}{\text{ + BaCl}}_{\text{2}}{}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{BaSO}}_{\text{4}}{}_{\left(\text{s}\right)}{\text{ + 2NaCl}}_{\left(\text{aq}\right)}$

Explanation of Solution

To Write: The complete balanced equation for the given incomplete reaction.

Sodium sulfate reacts with barium  chloride to form sodium chloride and barium sulfate solution.

${\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}{}_{\left(\text{aq}\right)}{\text{ + BaCl}}_{\text{2}}{}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{BaSO}}_{\text{4}}{}_{\left(\text{s}\right)}{\text{ + 2NaCl}}_{\left(\text{aq}\right)}$

The balanced equation is given as follows,

${\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}{}_{\left(\text{aq}\right)}{\text{ + BaCl}}_{\text{2}}{}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{BaSO}}_{\text{4}}{}_{\left(\text{s}\right)}{\text{ + 2NaCl}}_{\left(\text{aq}\right)}$

There are two sodium, one barium, one sulfur, two chlorine and four oxygen atoms on reactant side.  Product side has one barium, one sulfur, one sodium, one chlorine and four oxygen.  Only sodium chloride gets coefficient two and balances the equation.  Now in both sides the elements are balanced.

(c)

Interpretation Introduction

Interpretation:

The complete balanced equation for the given incomplete reaction has to be written.

Concept Introduction:

Balanced Chemical equation:

A balanced chemical equation is an equation which contains same elements in same number on both the sides (reactant and product side) of the chemical equation thereby obeying the law of conservation of mass.

Answer to Problem 21.94QP

${\text{K}}_{\text{2}}{\text{CO}}_{\text{3}}{}_{\left(\text{aq}\right)}\text{ + Ca}{\left(\text{OH}\right)}_{\text{2}}{}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{CaCO}}_{\text{3}}{}_{\left(\text{s}\right)}{\text{ + 2KOH}}_{\left(\text{aq}\right)}$

Explanation of Solution

To Write: The complete balanced equation for the given incomplete reaction.

Potassium carbonate reacts with calcium hydroxide to form calcium carbonate precipitate.

${\text{K}}_{\text{2}}{\text{CO}}_{\text{3}}{}_{\left(\text{aq}\right)}\text{ + Ca}{\left(\text{OH}\right)}_{\text{2}}{}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{CaCO}}_{\text{3}}{}_{\left(\text{s}\right)}{\text{ + KOH}}_{\left(\text{aq}\right)}$

The balanced equation is given as follows,

${\text{K}}_{\text{2}}{\text{CO}}_{\text{3}}{}_{\left(\text{aq}\right)}\text{ + Ca}{\left(\text{OH}\right)}_{\text{2}}{}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{CaCO}}_{\text{3}}{}_{\left(\text{s}\right)}{\text{ + 2KOH}}_{\left(\text{aq}\right)}$

Potassium hydroxide gets coefficient two because potassium carbonate has two potassium atoms.  Now in both sides the elements are balanced.

(d)

Interpretation Introduction

Interpretation:

The complete balanced equation for the given incomplete reaction has to be written.

Concept Introduction:

Balanced Chemical equation:

A balanced chemical equation is an equation which contains same elements in same number on both the sides (reactant and product side) of the chemical equation thereby obeying the law of conservation of mass.

Answer to Problem 21.94QP

${\text{2Li}}_{\left(\text{s}\right)}{\text{ + 2HCl}}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{2LiCl}}_{\left(\text{aq}\right)}{\text{ + H}}_{\text{2}}{}_{\left(\text{g}\right)}$

Explanation of Solution

To Write: The complete balanced equation for the given incomplete reaction.

Lithium reacts with hydrochloric acid which gives lithium chloride and hydrogen gas.

${\text{Li}}_{\left(\text{s}\right)}{\text{ + HCl}}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{LiCl}}_{\left(\text{aq}\right)}{\text{ + H}}_{\text{2}}{}_{\left(\text{g}\right)}$

The balanced equation is given as follows,

${\text{2Li}}_{\left(\text{s}\right)}{\text{ + 2HCl}}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{2LiCl}}_{\left(\text{aq}\right)}{\text{ + H}}_{\text{2}}{}_{\left(\text{g}\right)}$

Hydrogen chloride, lithium chloride and lithium gets coefficient two due to two hydrogen atoms in hydrogen gas. Now in both sides the elements are balanced.

(e)

Interpretation Introduction

Interpretation:

The complete balanced equation for the given incomplete reaction has to be written.

Concept Introduction:

Balanced Chemical equation:

A balanced chemical equation is an equation which contains same elements in same number on both the sides (reactant and product side) of the chemical equation thereby obeying the law of conservation of mass.

Answer to Problem 21.94QP

${\text{4Na}}_{\left(\text{s}\right)}{\text{ + ZrCl}}_{\text{4}}{}_{\left(\text{g}\right)}\stackrel{}{\to }{\text{4NaCl}}_{\left(\text{s}\right)}{\text{ + Zr}}_{\left(\text{s}\right)}$

Explanation of Solution

To Write: The complete balanced equation for the given incomplete reaction.

Sodium reacts with zirconium chloride which gives sodium chloride and zirconium.

${\text{Na}}_{\left(\text{s}\right)}{\text{ + ZrCl}}_{\text{4}}{}_{\left(\text{g}\right)}\stackrel{}{\to }{\text{NaCl}}_{\left(\text{s}\right)}{\text{ + Zr}}_{\left(\text{s}\right)}$

The balanced equation is given as follows,

${\text{4Na}}_{\left(\text{s}\right)}{\text{ + ZrCl}}_{\text{4}}{}_{\left(\text{g}\right)}\stackrel{}{\to }{\text{4NaCl}}_{\left(\text{s}\right)}{\text{ + Zr}}_{\left(\text{s}\right)}$

Zirconium chloride has four chloride atoms which gives rise to coefficient four for sodium chloride and sodium.  Now in both sides the elements are balanced.