Chapter 7, Problem 86AP

Interpretation Introduction

Interpretation:

The following table needs to be completed with respect to formation of precipitate:

	${\text{CaCl}}_{\text{2}}$	$\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$	${\left({\text{NH}}_{\text{4}}\right)}_{\text{3}}{\text{PO}}_{\text{4}}$
${\text{Na}}_2{\text{CO}}_3$
${\text{AgNO}}_{\text{3}}$
${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$

Concept Introduction:

A balanced chemical equation is an equation that contains same number of atoms as well as of each element of reactants and products of reaction.

There are following solubility rules:

1. The salts formed from sodium, potassium and ammonium ions are soluble in nature.
2. All sulfate salts are soluble except ${\text{CaSO}}_4$, ${\text{PbSO}}_4$ and ${\text{BaSO}}_4$
3. All nitrate salts are soluble. The formula of nitrate polyatomic ion is ${\text{NO}}_3^{-}$.
4. All the salts formed from chloride, bromide and iodide are soluble except those with ${\text{Pb}}^{2+}$ and ${\text{Ag}}^{+}$.
5. All sulfate salts are insoluble except ${\text{Na}}_{\text{2}}{\text{SO}}_{\text{3}}$, ${\text{K}}_{\text{2}}{\text{SO}}_{\text{3}}$ and ${\left({\text{NH}}_4\right)}_{\text{2}}{\text{SO}}_{\text{3}}$.
6. All sulfides are insoluble except ${\text{Na}}_{\text{2}}\text{S}$, ${\text{K}}_{\text{2}}\text{S}$ and ${\left({\text{NH}}_4\right)}_{\text{2}}\text{S}$.
7. All oxides and hydroxides are insoluble except ${\text{Na}}_{\text{2}}\text{O}$ /NaOH, ${\text{K}}_{\text{2}}\text{O}$ /KOH and $\text{BaO}/\text{Ba}{\left(\text{OH}\right)}_{\text{2}}$.
8. All carbonates are insoluble except ${\text{Na}}_{\text{2}}{\text{CO}}_3$, ${\text{K}}_{\text{2}}{\text{CO}}_{\text{3}}$ and ${\left({\text{NH}}_4\right)}_{\text{2}}{\text{CO}}_{\text{3}}$.

Answer to Problem 86AP

	${\text{CaCl}}_{\text{2}}$	$\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$	${\left({\text{NH}}_{\text{4}}\right)}_{\text{3}}{\text{PO}}_{\text{4}}$
${\text{Na}}_2{\text{CO}}_3$	${\text{CaCO}}_3$	${\text{PbCO}}_3$	No
${\text{AgNO}}_{\text{3}}$	$\text{AgCl}$	No	${\text{Ag}}_{\text{3}}{\left({\text{PO}}_{\text{4}}\right)}_{\text{2}}$
${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$	${\text{CaSO}}_4$	${\text{PbSO}}_4$	No

Explanation of Solution

The explanation is as follows.

• The balanced reaction of ${\text{CaCl}}_{\text{2}}$ and ${\text{Na}}_2{\text{CO}}_3$ form the following compounds.

${\text{Na}}_2{\text{CO}}_3\left(\text{a}\text{q}\right)+{\text{CaCl}}_{\text{2}}\left(\text{a}\text{q}\right)\stackrel{}{\to }{\text{CaCO}}_3\left(\text{s}\right)+2\text{NaCl}\left(\text{a}\text{q}\right)$

In the above formed products, ${\text{CaCO}}_3$ is insoluble with reference to solubility guidelines which indicate all carbonates are insoluble except the salts of ${\text{NH}}_{\text{4}}^{\text{+}}\text{,}{\text{K}}^{\text{+}}\text{and}{\text{Na}}^{\text{+}}$.

• The balanced reaction of ${\text{Na}}_2{\text{CO}}_3$ and $\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ is as follows.

${\text{Na}}_2{\text{CO}}_3\left(\text{a}\text{q}\right)+\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\left(\text{a}\text{q}\right)\stackrel{}{\to }{\text{PbCO}}_3\left(\text{s}\right)+2{\text{NaNO}}_3\left(\text{a}\text{q}\right)$

In the above formed products, we conclude that ${\text{PbCO}}_3$ is insoluble with reference to solubility guidelines which indicate all carbonates are insoluble except the salts of ${\text{NH}}_{\text{4}}^{\text{+}}\text{,}{\text{K}}^{\text{+}}\text{and}{\text{Na}}^{\text{+}}$.

• The balanced reaction of ${\text{Na}}_2{\text{CO}}_3$ and ${\left({\text{NH}}_4\right)}_3{\text{PO}}_{\text{4}}$ is as follows.

${\text{3Na}}_2{\text{CO}}_3\left(\text{a}\text{q}\right)+2{\left({\text{NH}}_{\text{4}}\right)}_3{\text{PO}}_{\text{4}}\left(\text{a}\text{q}\right)\stackrel{}{\to }2{\text{Na}}_{\text{3}}{\text{PO}}_{\text{4}}\left(\text{a}\text{q}\right)+{\left({\text{NH}}_{\text{4}}\right)}_{\text{2}}{\text{CO}}_{\text{3}}\left(\text{a}\text{q}\right)$

The above formed products both are soluble in all conditions. Hence, there is no precipitate that would be formed in the reaction.

• The balanced reaction of ${\text{AgNO}}_{\text{3}}$ and ${\text{CaCl}}_2$ is as follows.

${\text{AgNO}}_3\left(\text{a}\text{q}\right)+{\text{CaCl}}_{\text{2}}\left(\text{a}\text{q}\right)\stackrel{}{\to }\text{AgCl}\left(\text{s}\right)+\text{Ca}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\left(\text{a}\text{q}\right)$

In the above formed products, we conclude that $\text{AgCl}$ is insoluble with reference to solubility guidelines which indicate all chlorides are soluble except the salts of $\text{AgCl,}{\text{Hg}}_{\text{2}}{\text{Cl}}_{\text{2}}\text{and}{\text{PbCl}}_{\text{2}}$

• The balanced reaction of ${\text{AgNO}}_{\text{3}}$ and $\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ is as follows.

${\text{AgNO}}_3\left(\text{a}\text{q}\right)+\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\left(\text{a}\text{q}\right)\stackrel{}{\to }\text{No}\text{reaction}$

There are no characteristic solid products formed in the above reaction.

• The balanced reaction of ${\text{AgNO}}_{\text{3}}$ and ${\left({\text{NH}}_4\right)}_3{\text{PO}}_{\text{4}}$ is as follows.

${\text{3AgNO}}_3\left(\text{a}\text{q}\right)+{\left({\text{NH}}_4\right)}_3{\text{PO}}_{\text{4}}\left(\text{a}\text{q}\right)\stackrel{}{\to }{\text{Ag}}_3{\text{PO}}_4\left(\text{s}\right)+\text{3}{\text{NH}}_4{\text{NO}}_3\left(\text{a}\text{q}\right)$

In the above formed products, we conclude that ${\text{Ag}}_3{\text{PO}}_4$ is insoluble with reference to solubility guidelines which indicate all chlorides are soluble except the salts of $\text{AgCl,}{\text{Hg}}_{\text{2}}{\text{Cl}}_{\text{2}}\text{and}{\text{PbCl}}_{\text{2}}$.

• The balanced reaction of ${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$ and ${\text{CaCl}}_2$ is as follows.

${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}\left(\text{a}\text{q}\right)+{\text{CaCl}}_{\text{2}}\left(\text{a}\text{q}\right)\stackrel{}{\to }{\text{CaSO}}_{\text{4}}\left(\text{s}\right)+2\text{KCl}\left(\text{a}\text{q}\right)$

In the above formed products, we conclude that ${\text{CaSO}}_{\text{4}}$ is insoluble with reference to solubility guidelines.

• The balanced reaction of ${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$ and $\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ is as follows.

${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}\left(\text{a}\text{q}\right)+\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\left(\text{a}\text{q}\right)\stackrel{}{\to }{\text{PbSO}}_{\text{4}}\left(\text{s}\right)+2{\text{KNO}}_3\left(\text{a}\text{q}\right)$

In the above formed products, we conclude that ${\text{PbSO}}_{\text{4}}$ is insoluble with reference to solubility guidelines.

• The balanced reaction of ${\text{AgNO}}_{\text{3}}$ and ${\left({\text{NH}}_4\right)}_3{\text{PO}}_{\text{4}}$ is as follows.

${\text{3K}}_{\text{2}}{\text{SO}}_{\text{4}}\left(\text{a}\text{q}\right)+2{\left({\text{NH}}_4\right)}_3{\text{PO}}_{\text{4}}\left(\text{a}\text{q}\right)\stackrel{}{\to }2{\text{K}}_3{\text{PO}}_4\left(\text{a}\text{q}\right)+3{\left({\text{NH}}_{\text{4}}\right)}_{\text{2}}{\text{SO}}_{\text{4}}\left(\text{a}\text{q}\right)$

There are no characteristic solid products formed in the above reaction.

Conclusion

Thus, the complete table is as follows:

	${\text{CaCl}}_{\text{2}}$	$\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$	${\left({\text{NH}}_{\text{4}}\right)}_{\text{3}}{\text{PO}}_{\text{4}}$
${\text{Na}}_2{\text{CO}}_3$	${\text{CaCO}}_3$	${\text{PbCO}}_3$	No
${\text{AgNO}}_{\text{3}}$	$\text{AgCl}$	No	${\text{Ag}}_{\text{3}}{\left({\text{PO}}_{\text{4}}\right)}_{\text{2}}$
${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$	${\text{CaSO}}_4$	${\text{PbSO}}_4$	No