Question

How much heat is needed to change 5.42 grams of solid gold to liquid gold at its melting point of 1,063°C? The latent heat of fusion of gold is 66.6 J/g.

A –12.3 joules
B 12.3 joules
C –361 joules
D 361 joules

Answer 1

D. 361 joules

Step-by-step explanation:

right on edge

Answer 2

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.