Question

Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4​ and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls.


1. Why there is an increase in temperature in beakers A and B?

2. Why there is fall in temperature in beaker C ?

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Answer 1

Answer:

When heat is released (Exothermic process)surrounding gets warm means temperature rises.

When heat is absorbed (Endothermic process) surrounding gets cold means temperature falls.

Therfore in both A and B exothermic reactions are taking place resulting in rise in temperature.

On the other hand in beaker C, an endothermic reaction is taking place as heat is being absorbed, resulting in a decrease in temperature.