Question

which of the following are exothermic process?
I. Reaction of water with quick lime
ii. Dilution of an acid
iii. Evaporation of water
iv. Sublimation of Camphor
(a) I and ii
(b) ii and iii
(c) I and iv
(d) iii and iv​

Answer 1

Answer: a) i and ii

Explanation:

an exothermic process is that in which energy released> energy absorbed

in Reaction of water with quick lime and Dilution of an acid a lot of energy is released, hence they're exothermic reactions.

Answer 2

Answer:

d) (ii) and (iv)

Explanation:

Sublimation of ice is a direct phase transition from solid to gas without passing through an intermediate liquid state. The process requires additional energy, therefore, it is an endothermic reaction and the amount of heat absorbed is called heat of sublimation.

[S]  -------heat------>  [V]      ........Sublimation  

Evaporation is the process in which water changes from liquid to gas or vapour. This endothermic process occurs with the absorption of heat and the rate of evaporation increases with increase in temperature.

[L]  --------heat ------->[V]      .........Evaporation