How much energy (in kilojoules) is required to convert 225 of diethyl ether at its boiling point from liquid to vapor if its density is 0.7138 ?

How much energy (in kilojoules) is required to convert 225 of diethyl ether at its boiling point from liquid to vapor if its density is 0.7138 ? The familiar "ether" used as an anesthetic agent is diethyl ether, Its heat of vaporization is +26.5 at its boiling point.