How much heat is absorbed if 45 grams of sweat is evaporated from someone's skin? ∆Hvap for water at body temperature is 2.41 kJ/g.
q = mass H2O x dHvap.
78
108.5
To calculate the amount of heat absorbed when 45 grams of sweat is evaporated, we will use the formula:
Heat absorbed = Mass of sweat (in grams) × ∆Hvap
Given:
Mass of sweat (m) = 45 grams
∆Hvap for water at body temperature = 2.41 kJ/g
First, let's convert ∆Hvap from kJ/g to J/g, since the mass of sweat is given in grams:
∆Hvap = 2.41 kJ/g × 1000 J/kJ = 2410 J/g
Now, we can calculate the heat absorbed:
Heat absorbed = 45 grams × 2410 J/g
Calculating it:
Heat absorbed = 108,450 J
Therefore, when 45 grams of sweat is evaporated, approximately 108,450 Joules of heat is absorbed.