JEE Main levelSingle correct optionDifficulty 2 of 3ev126
Discharge of hot water from a power plant into a river harms fish mainly because warm water:
Adissolves less oxygen, while the oxygen demand of organisms increases
Bdissolves more oxygen, which becomes toxic
Chas a lower pH than cold water in every case
Dhas no effect on the rate of bacterial decay
Answer: A
Solubility of gases in water decreases as temperature rises, so dissolved oxygen falls. At the same time metabolic and decay rates rise, increasing the oxygen demand.