Chapter 9, Problem 108A

Interpretation Introduction

(a)

Interpretation:

The balanced chemical equation for the word equation needs to be determined.

$\text{ammonium}\text{phosphate}\left(aq\right)+\text{chromium}\left(\text{III}\right)\text{bromide}\left(aq\right)\to \text{ammonium}\text{bromide}\left(aq\right)+\text{chromium}\left(\text{III}\right)\text{phosphate}\left(s\right)$

Concept introduction:

Chemical equation is the symbolic description of a chemical reaction that products and reactants are indicating in terms of their chemical formula.

Answer to Problem 108A

The balance equation is as follows:

${\left({\text{NH}}_{\text{4}}\right)}_3{\text{PO}}_{\text{4}}\left(aq\right)+{\text{CrBr}}_{\text{3}}\left(aq\right)\to 3{\text{NH}}_{\text{4}}\text{Br}\left(aq\right)+{\text{CrPO}}_4\left(s\right)$

Explanation of Solution

The given word equation is as follows:

$\text{ammonium}\text{phosphate}\left(aq\right)+\text{chromium}\left(\text{III}\right)\text{bromide}\left(aq\right)\to \text{ammonium}\text{bromide}\left(aq\right)+\text{chromium}\left(\text{III}\right)\text{phosphate}\left(s\right)$

For this word equation skeleton equation is as follows:

${\left({\text{NH}}_{\text{4}}\right)}_3{\text{PO}}_{\text{4}}\left(aq\right)+{\text{CrBr}}_{\text{3}}\left(aq\right)\to {\text{NH}}_{\text{4}}\text{Br}\left(aq\right)+{\text{CrPO}}_4\left(s\right)$

On the reactant side there are 3 ammonium cations and there is only one ammonium cation in the product side. There is only 1 bromine atom in the product side and in the reactant side there are 3 bromine atoms. Thus add coefficient 3 to ammonium bromide in the product. Now balance chemical equation is as follows:

${\left({\text{NH}}_{\text{4}}\right)}_3{\text{PO}}_{\text{4}}\left(aq\right)+{\text{CrBr}}_{\text{3}}\left(aq\right)\to 3{\text{NH}}_{\text{4}}\text{Br}\left(aq\right)+{\text{CrPO}}_4\left(s\right)$

(b)

Interpretation Introduction

Interpretation:

The given word equation needs to be balanced.

$\text{chromium}\left(\text{VI}\right)\text{hydroxide}\left(s\right)\to \text{chromium}\left(\text{VI}\right)\text{oxide}\left(s\right)+\text{water}\left(l\right)$

Concept introduction:

Chemical equation is the symbolic description of a chemical reaction that products and reactants are indicating in terms of their chemical formula.

Answer to Problem 108A

The balance equation is as follows:

$\text{Cr}{\left(\text{OH}\right)}_6\left(s\right)\to {\text{CrO}}_{\text{3}}\left(s\right)+3{\text{H}}_{\text{2}}\text{O}\left(l\right)$

Explanation of Solution

The given word equation is as follows:

$\text{chromium}\left(\text{VI}\right)\text{hydroxide}\left(s\right)\to \text{chromium}\left(\text{VI}\right)\text{oxide}\left(s\right)+\text{water}\left(l\right)$

For this word equation skeleton equation is as follows:

$\text{Cr}{\left(\text{OH}\right)}_6\left(s\right)\to {\text{CrO}}_{\text{3}}\left(s\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)$

On the reactant side there are 6 oxygen and hydrogen atoms and in the product side there are 4 oxygen and 2 hydrogen atoms. There is only 1 bromine atom in the product side and in the reactant side there are 3 bromine atoms. Thus, add coefficient 3 to water in product. Now balance chemical equation is as follows:

$\text{Cr}{\left(\text{OH}\right)}_6\left(s\right)\to {\text{CrO}}_{\text{3}}\left(s\right)+3{\text{H}}_{\text{2}}\text{O}\left(l\right)$

(c)

Interpretation Introduction

Interpretation:

The given word equation needs to be balanced.

$\text{aluminum}\left(s\right)+\text{copper}\left(\text{I}\right)\text{chloride}\left(aq\right)\to \text{aluminum choride}\left(aq\right)+\text{copper}\left(s\right)$

Concept introduction:

Chemical equation is the symbolic description of a chemical reaction that products and reactants are indicating in terms of their chemical formula.

Answer to Problem 108A

The balance equation is as follows:

$\text{Al}\left(s\right)+3\text{CuCl}\left(aq\right)\to {\text{AlCl}}_{\text{3}}\left(aq\right)+3\text{Cu}\left(s\right)$

Explanation of Solution

The given word equation is as follows:

$\text{aluminum}\left(s\right)+\text{copper}\left(\text{I}\right)\text{chloride}\left(aq\right)\to \text{aluminum choride}\left(aq\right)+\text{copper}\left(s\right)$

For this word equation skeleton equation is as follows:

$\text{Al}\left(s\right)+\text{CuCl}\left(aq\right)\to {\text{AlCl}}_{\text{3}}\left(aq\right)+\text{Cu}\left(s\right)$

On the reactant side there is only 1 chlorine atom and in the product side there are 3 chlorine atoms. Thus add coefficient 3 for reactant copper (I) chloride and add 3 coefficients to copper atom in the product side. Now balance chemical equation is as follows:

$\text{Al}\left(s\right)+3\text{CuCl}\left(aq\right)\to {\text{AlCl}}_{\text{3}}\left(aq\right)+3\text{Cu}\left(s\right)$

(d)

Interpretation Introduction

Interpretation:

The given word equation needs to be balanced.

$\text{potassium}\text{iodide}\left(aq\right)+\text{mercury}\left(\text{I}\right)\text{nitrate}\left(aq\right)\to \text{potassium}\text{nitrate}\left(aq\right)+\text{mercury}\left(\text{I}\right)\text{iodide}\left(s\right)$

Concept introduction:

Chemical equation is the symbolic description of a chemical reaction that products and reactants are indicating in terms of their chemical formula.

Answer to Problem 108A

The balance equation is as follows:

$\text{KI}\left(aq\right)+{\text{HgNO}}_{\text{3}}\left(l\right)\to {\text{KNO}}_{\text{3}}\left(aq\right)+\text{HgI}\left(s\right)$

Explanation of Solution

The given word equation is as follows:

$\text{potassium}\text{iodide}\left(aq\right)+\text{mercury}\left(\text{I}\right)\text{nitrate}\left(aq\right)\to \text{potassium}\text{nitrate}\left(aq\right)+\text{mercury}\left(\text{I}\right)\text{iodide}\left(s\right)$

For this word equation skeleton equation is as follows:

$\text{KI}\left(aq\right)+{\text{HgNO}}_{\text{3}}\left(l\right)\to {\text{KNO}}_{\text{3}}\left(aq\right)+\text{HgI}\left(s\right)$

In this reaction, all atoms are balanced for reactant and product side. Thus no coefficients are needed and balanced equation is as follows:

$\text{KI}\left(aq\right)+{\text{HgNO}}_{\text{3}}\left(l\right)\to {\text{KNO}}_{\text{3}}\left(aq\right)+\text{HgI}\left(s\right)$