The human body obtains 835 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize water at 100 ∘C, how many grams of water could be vaporized? The heat of vaporization of water at 100 ∘C is 40.7 kJ/mol. Assume that the density of water is 1.0 g/mL.

Question

Chemistry

Yasmin Bradley

26 February, 13:39

The human body obtains 835 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize water at 100 ∘C, how many grams of water could be vaporized? The heat of vaporization of water at 100 ∘C is 40.7 kJ/mol. Assume that the density of water is 1.0 g/mL.

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Brice Pearson · Answer 1

If there is 1 mol vaporized per 40.7 kJ of heat, that means 20.516 mol of water can be vaporized, found by the equation 835 kJ/40.7 kJ = 20.516 mol. To find the mass of 20.516 mol of water, you take the mass of one mol of water, 18.0148 grams, found by multiplying avogadro's number (6.022 x 10^23) by the mass of one water molecule, and multiply it by 20.516. This results in 369.5916368 grams of water vaporized.