Question

If it takes 6.02 kj of heat energy to melt a mole of ice, how much heat is absorbed when 6.30 g of water melts? 21.0 j 2.10 kj 21 kj 0.210 kj

Answer 1

First, let's see how many moles correspond to 6.30 g of water.
The molar weight of water is 18.01 g/mol, so
$n= \frac{6.30 g}{18.01 g/mol}=0.35 mol$
Then we know it takes 6.02 kJ to melt 1 mole of ice, so if we have 0.35 mol, the amount of heat needed will be
$Q=6.02 kJ \cdot 0.35 mol=2.10 kJ$