Calculating Heat Released During Water Freezing

[protractor]

Homework Statement

Calculate the amount of heat emitted when 12.4 g of water freezes to solid air.

Homework Equations

heat of fusion = 6.02 KJ
1 mol H₂O = 18.02 g H₂O

The Attempt at a Solution

12.4 g H₂O x 1 mol H₂O/ 18.02 g H₂O x (-6.02 KJ) / 1 mol H₂O = - 4.14 kJ

I am unsure whether the answer is positive or negative.
The answer in the book is positive 4.14 kJ, but freezing is exothermic ( releasing energy).

 

[DrClaude]

You have to pay attention to the language. The question asks for "the amount of heat emitted", which will be minus the heat change of the water, that latter being what you calculated.