Question

It has been determined that the body can generate 5500 kJ of energy during one hour of strenuous exercise. Perspiration is the body’s mechanism for eliminating this heat. What mass of water would have to be evaporated through perspiration to rid the body of the heat generated during 2 hours of exercise? (The heat of vaporization of water is 40.6 kJ/mol.)

Answer 1

4.88 kg

Step-by-step explanation:

Amount of energy generated in 1 hour of exercise = 5500 kJ

Thus,

Amount of energy generated in 2 hours of exercise = 5500*2 kJ

So,

Amount of energy generated in 2 hours of exercise = 11000 kJ

Heat of vaporization of water = 40.6 kJ/mol

40.6 kJ of energy is required to vaporize 1 mole of water

Also,

11000 kJ of energy is required to vaporize (1/40.6) * 11000 mole of water

Moles of water = 270.936 moles

Molar mass of water = 18 g/mol

Mass = Moles * Molar mass = 270.936 * 18 g = 4876.8473 g

Also,

1 g = 0.001 kg

So, mass of water = 4.88 kg