How many molecules are there in 1.5 mol of methane

A mole of something means that there are 6.02 X 10^23 of that something. So, a mole of methane molecules is 6.02 X 10^23 methane molecules. So, 1.5 moles of methane will contain 1.5*(6.02 X 10^23) = 9.0 X 10^23 methane molecules

Explanation:

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

c, liquids evaporate, creating a gas