Calculate the mass of gold that occupies the same volume as 62.9 g of cobalt. The density of cobalt is 8.90 g/cm3 and the density of gold is 19.30 g/cm3 .

241.82 kJ is released

Explanation:

The reaction indicates that 483.64 kJ of energy is released when TWO moles of H2O(g) is formed. You're looking to find the amount of energy released when only ONE mole of H2O forms, so that would be half the amount of energy released in the reaction (as one mole is a half of two).

483.64 / 2 = 241.82 kJ

So, your answer would be 241.82 kJ is released.