Chapter 18, Problem 128A

Interpretation Introduction

Interpretation: The substance whose solubility decreases in water with an increase in temperature from the given substances is to be identified.

Concept introduction: Solubility is the maximum amount of a chemical that will dissolve in a given quantity of solvent at a particular temperature. Solubility is a defining characteristic of a particular solute-solvent combination, and the solubilities of various compounds vary considerably.

Answer to Problem 128A

From the given substances, the solubility of (b) ${\text{NH}}_3\left(g\right)$ in water decrease with an increase in temperature.

Explanation of Solution

The given substances are as follows:

1. ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}\left(s\right)$
2. ${\text{NH}}_3\left(g\right)$
3. $\text{KI}\left(s\right)$
4. $\text{NaCl}\left(s\right)$

The solubility of a solid increases while the solubility of a gas decreases as temperature increases. Ammonia is the only gaseous substance among the four mentioned substances. Therefore, only the solubility of (b) ${\text{NH}}_3\left(g\right)$ in water decrease with an increase in temperature from the given substances.

Conclusion

From the given substances, the solubility of (b) ${\text{NH}}_3\left(g\right)$ in water decrease with an increase in temperature.