Question

(4) while you were "sweating" your chemistry test, water vapor evaporates from your body, absorbing 125 kj of energy. (assume no temperature change). what mass of water evaporates?

Answer 1

The mass of water that evaporated from the body after absorbing 125 kJ of energy can be calculated using the enthalpy of vaporization for water and the given value for latent heat of vaporization, we find mass to be 0.05 kg.

Step-by-step explanation:

The question pertains to enthalpy of vaporization, which is a concept in Chemistry concerned with the energy required for a substance to change from liquid to gas without a temperature change. Given that the water vapor from the body absorbs 125 kJ of energy during the evaporation process, and knowing the latent heat of vaporization of water is approximately 2256 kJ/kg, we can calculate the mass of water evaporated.

To find the mass (m) that has evaporated, we use the formula Q = mL, where Q is the heat absorbed and L is the latent heat of vaporization. With the provided values, we rearrange the formula to solve for m: m = Q/L. Substituting the values, we get m = 125 kJ / 2256 kJ/kg = 0.05 Kg.

Answer 2

The heat absorbed by the water that evaporates from the body is the so called latent vaporization heat of water.

The standard latent vaporization heat of water is 2,264.705 kJ / kg.

So, you just have to divide 125 kJ / 2,264.705 kJ/kg = 0.0552 kg = 55.2 g

Answer: 55.2 g