How much energy is released when 37.8 g of water freezes? the heat of fusion for water is 6.02 kj/mol. the amount of heat energy released = kj?

Answer is: 12.642 kJ of heat is released.
m(H₂O) = 37.8 g; mass of water.
M(H₂O) = 2 · 1 g/mol + 16 g/mo = 18 g/mol.
n(H₂O) = m(H₂O) ÷ M(H₂O).
n(H₂O) = 37.8 g ÷ 18 g/mol.
n(H₂O) = 2,1 mol; amount of substance.
ΔHfus = 6.02 kJ/mol; the heat of fusion.
Q = n(H₂O) · ΔHfus.
Q = 2.1 mol · 6.02 kJ/mol.
Q = 12.642 kJ.

The answer is d for this question