How much energy is required to vaporize 48.7 g of dichloromethane (ch2cl2) at its boiling point, if its δhvap is 31.6 kj/mol? how much energy is required to vaporize 48.7 g of dichloromethane (ch2cl2) at its boiling point, if its δhvap is 31.6 kj/mol? 6.49 kj 15.4 kj 18.1 kj 55.1 kj 31.2 kj?

This energy required is the latent heat, which is required for physical transformations. Specifically, when it involves changing liquid to gas, this latent heat is called the heat of vaporization. The formula is:

Q = mΔHvap
The molar mass of the compound is 
Q = (48.7 g)(31.6 kJ/mol)(1 mol/84.93 g)
Q = 18.12 kJ

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You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.