How many grams of ice at 0c could be melted by the additional of 0.400 kj of heat

To solve this we will use the formula q=mc delta T. Q is heat, m is mass, c is specific heat and delta T is change in temperature. because it is a phase change problem, temperature does not apply. Also, we will use heat of fusion of water (344J/g) instead of specific heat. We will also convert 0.400 kJ to J, which becomes 400 J.

0.400 kJ x (1000 J/1 kJ) = 400 J 

400 J = (g) x (334 J/g) 

g = 1.198 

Because of sig figs, we will round to 1.20 grams (3 sig figs). The answer is 1.20 grams.

It shows that the experiment is designed properly.

They can measure  the amount of energy gained or lost