(a) State two factors that affect the rate of evaporation of a liquid. (b) Explain...

Explanation

(a) Factors affecting the rate

i. Surface area of the liquid (exposed surface area)

ii. Temperature of the liquid

iii. Wind/ drought.

iv. Humidity/ amount of water vapour

v. Nature of the liquid

vi. Air pressure

(b) Explanation of latent heat;

The energy needed to change the state of a substance without a change in temperature.

(c)(i) Water in a clay pot cooler than in a rubber container;

A clay pot has pores which allows evaporation to occur while a plastic container has no pores.

(ii) Pressure cooker cooks faster than ordinary pot;

Pressure cooker raises the pressure within it, which raises the temperature to/above the boiling point thus cooks faster.

(d)(i) Calculation of latent heat of fusion of the body

Ivt =mL

mL= 12 x 40 x 1400

= 6.72 x 10\^{5}\)j

(ii) Calculation of specific heat capacity of the body

C = \(\frac{Ivt}{m \bigtriangleup \theta}\)

= \(\frac{12 \times 40 \times 72}{1.5 \times 60}\)

= 384 jkg\(^{-1}\) K\(^{-1}\)

(e) difference between evaporation and boiling