Question

Predict whether each of the following ionic compounds is soluble in water:

a.$LiCl$

b.$PbS$

c.$BaC{O}_3$

d. $K_{2}O$

e.$Fe{\left(N{O}_3\right)}_3$

Short answer

(part a) The ionic compound $LiCl$is soluble in water.

(part b) The ionic compound $PbS$is insoluble in water.

(part c) The ionic compound$BaC{O}_3$is insoluble in water.

(part d) The ionic compound$K_{2}O$is soluble in water.

(part e) The ionic compound$Fe{\left(N{O}_3\right)}_3$is soluble in water.

Step-by-step solution

Introduction (part a).

If an ionic compound contains one of the following ions, it is soluble in water:

Positive ions: ${\mathrm{Li}}^{+},{\mathrm{Na}}^{+},{\mathrm{K}}^{+},{\mathrm{Rb}}^{+},{\mathrm{Cs}}^{+},{\mathrm{NH}}_4^{+}$.

Negative ions:${\mathrm{NO}}_3^{-},{\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2^{-},{\mathrm{Cl}}^{-},{\mathrm{Br}}^{-},{\mathrm{I}}^{-}$

Given Information (part a). 

Given:

$LiCl$

Explanation (part a). 

$L{i}^{+}$and $C{l}^{-}$ions are present in the ionic compound $LiCl.$

Hence, $LiCl$is soluble in water.

Given Information (part b).  

Given:

$PbS$

Explanation (part b). 

$P{b}^{2+}$and $S^{2-}$ions are present in the ionic compound $PbS.$The majority of sulphide containing $S^{2-}$ ions are insoluble. As a result, $PbS$ is insoluble in water.

Given Information (part c). 

Given:

$BaC{O}_3$

Explanation (part c). 

The ionic compound $BaC{O}_3$contains $B{a}^{2+}$and $C{O_3}^{2-}$ions. Carbonates with $C{O_3}^{2-}$ ions are insoluble in water. For this reason,$BaC{O}_3$ is insoluble in water.

Given Information (part d). 

Given:

$K_{2}O$

Explanation (part d). 

$K_{2}O$is an ionic compound that contains $K^{+}$ions. In water, $K^{+}$ ions are always soluble. As a result,$K_{2}O$ is soluble in water.

Given Information (part e). 

Given:

$Fe{\left(N{O}_3\right)}_3$

Explanation (part e).

$Fe{\left(N{O}_3\right)}_3$is soluble in water because the ions present in this always soluble in water.