Question

if the heat of fusion of ethonal is 0.1 kj/g and the heat of vaporization of ethonal is 0.9 kj/g how much heat is needed to melt 10 g of ethanol?

Answer 1

Heat needed to to melt 10 g of ethanol : 1 kJ

Further explanation

The heat to change the phase can be formulated :

Q = mLf (melting/freezing)

Q = mLv (vaporization/condensation)

Lf=latent heat of fusion

Lv=latent heat of vaporization

mass of ethanol= 10 g

Heat needed to melt :

$\tt Q=m\times L_f\\\\Q=10~g\times 0.1~kJ/g\\\\Q=\boxed{\bold{1~kJ}}}$