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

Exothermic reactions are the reactions in which heat is released along with the formation of products and there is rise in temperature whereas endothermic reaction are accompanied by or requires the absorption of heat which results in fall of temperature.