It has been determined that the body can generate 5500 \(\mathrm{kJ}\) 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 \(\mathrm{kJ} / \mathrm{mol.} )\)

Short Answer

Expert verified
In the given problem, we have: Energy generated per hour = 5500 kJ/hour Duration of exercise = 2 hours Heat of vaporization of water = 40.6 kJ/mol Molar mass of water = 18.015 g/mol The total heat generated during the exercise is: Total heat generated = (5500 kJ/hour) × 2 hours = 11000 kJ Now, we can calculate the moles of water that must evaporate to remove the heat generated: moles of water = Total heat generated / Heat of vaporization of water moles of water = (11000 kJ) / (40.6 kJ/mol) ≈ 270.94 mol Finally, we can determine the mass of water corresponding to these moles: mass of water = moles of water × molar mass of water mass of water = (270.94 mol) × (18.015 g/mol) ≈ 4878.7 g Therefore, approximately 4878.7 g of water must be evaporated through perspiration to rid the body of the heat generated during 2 hours of exercise.

Step by step solution

01

Calculate the total heat generated in kJ during the exercise

The total heat generated can be found by multiplying the energy generated per hour by the number of hours the exercise lasts. In this case, 5500 kJ is generated each hour, and the exercise lasts for 2 hours. So the total heat generated is: Total heat generated = (5500 kJ/hour) × 2 hours
02

Determine the number of moles of water that must evaporate to remove the heat generated

To find the number of moles of water that must evaporate to eliminate the heat generated, use the formula: moles of water = Total heat generated / Heat of vaporization of water We already know the total heat generated and the heat of vaporization of water (40.6 kJ/mol), so we can plug those values into the formula to find the moles of water: moles of water = (Total heat generated) / (40.6 kJ/mol)
03

Calculate the mass of water that corresponds to the moles of water

Now that we have the number of moles of water, we can find the mass of water that corresponds to those moles. The molar mass of water is 18.015 g/mol. To find the mass of water, multiply the number of moles of water by the molar mass of water: mass of water = moles of water × molar mass of water Plug in the values for moles of water and the molar mass of water to find the mass of water: mass of water = (moles of water) × (18.015 g/mol) Now, you can calculate the mass of water that has to evaporate to eliminate the heat generated by the body during 2 hours of exercise.

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Most popular questions from this chapter

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