Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous `CuSO_(4)` 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. Which one of the followig statement (s) is (are) correct?
1. In beakers A and B, exothermic process has occurred.
2. In beakers A and B, endothermic process has occurred.
3. In beaker C, exothermic process has occurred.
4. In beaker C, endothermic process has occurred.

Options

A. (i) only
B. (ii) only
C. (i) and (iv)
D. (ii) and (iii)

Answer

C

Explanation

In beakers A and B, heat is given out, so the temperature of the solution increases, hence it is an exothermic reaction while in beaker C, heat is absorbed from water so temperature falls, hence it is an endothermic process.