A. steam burn is independent of relative humidity
B. steam possesses greater heat energy per unit mass
C. water boils at a higher temperature
D. steam burn is dependent on relative humidity
Correct Answer:
Option B – steam possesses greater heat energy per unit mass
Explanation
The specific latent heat of vaporization of steam is 2.1 x 106JKg-1
while the energy required to raise the temperature of a unit mass of water from 0°c to 100°c = C x Dt = 4200 x 100 = 420000 = 4.2 x 105 JKg-1
∴ steam possesses greater heat energy per unit mass