We can easily calculate for the heat Q needed to change 5.42 grams of solid gold to liquid gold at its melting point using the equation
Q = mLf,
where m is the mass of solid gold and Lf is the latent heat of fusion of gold.
Substituting the values to the equation we now have
Q = 5.42 g (66.6 J/g) = 360.972 J
Therefore we need 361 Joules to melt 5.42 grams of solid gold.
