Gas solubility generally increases when temperature decreases. Which option correctly identifies this statement?

• A. Temperature increases increases gas solubility
• B. Temperature decreases increases gas solubility
• C. Temperature has no effect
• D. Temperature changes only for solids

Answer: (B)

Gas solubility in a liquid depends on temperature, and for most gases, lowering the temperature increases how much gas can stay dissolved. When a gas dissolves, the process tends to release heat, so raising the temperature supplies energy that helps the dissolved gas escape back into the gas phase. With a fixed gas pressure, the amount dissolved thus decreases as temperature rises, which is why decreasing temperature leads to greater solubility. So the statement that temperature decreases increases gas solubility is the best description. The other ideas—temperature increasing increasing solubility, no effect, or temperature changing only for solids—don’t fit the typical behavior of gases in liquids.