Question

Which of these substances would be more soluble in cold water than warm water?

A. potassium chloride salt
B. sugar powder
C. sodium chloride crystals
D. oxygen gas

Answer 1

The solubility of substances in water can vary with temperature. Among the options provided, the substance that is typically more soluble in cold water than warm water is:

**D. oxygen gas**

While the solubility of most solids, like potassium chloride, sugar, and sodium chloride, generally increases with temperature, gases such as oxygen tend to be more soluble in colder water. This is because warmer water can hold less dissolved gas due to increased kinetic energy, which allows gas molecules to escape more easily from the liquid. Therefore, option D is the correct choice.