Answer to Question #266150 in Chemistry for josh

Question

A student boils 9.43 grams of an unknown substance into vapor. If completely vaporizing the substance required 8,720 joules of energy, what is the heat of vaporization?

Answer 1

Solution:

The heat of vaporization (∆H_vap) is defined as the amount of heat needed to turn 1g of a liquid into a vapor, without a rise in the temperature of the liquid.

Hence,

∆H_vap = (8720 J) / (9.43 g) = 924.7 J/g

∆H_vap = 924.7 J/g

Answer: The heat of vaporization (∆H_vap) is 924.7 J/g