Thermochemistry?

1 Answer
May 26, 2017

Answer:

Heat to evaporate 10 grams HOH = 5400 calories = 22,600 joules

Explanation:

The phase change energy of water can be calculated using
#Q = m DeltaH_(transition)# where #m# is mass and #DeltaH_(transition)# is the transition constant per unit mass of water. For evaporation or condensation the constant is Heat of Vaporization #DeltaH_(v) = 540 ("calories")/(gram)# and for freezing or melting the constant is Heat of Fusion #DeltaH_f = 80 "calories"/"gram".# To convert to Joules, use the relationship 4.184 joules = 1 calorie.