Chemistry
posted by jessica .
A quantity of ice at 0.0°C was added to 25.0 g of water at 21.0°C to give water at 0.0°C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g · °C).
_g

(g ice x heat fusion) +[g melted ice x specific heat H2O x (TfinalTinitial)] + [g H2O x specific heat water x (TfinalTinitial)] = 0
You have only one unknown namely g ice. Solve for that. I estimated the answer to be about 7g ice at zero. Note that I have three terms above; i.e., ice + melted ice + water at 25. The middle term (melted ice) is multiplied by (TfinalTinitial) but since Tfinal is zero and Tinitial is zero then TfTi = 0 and anything times zero is zero so the middle term is zero.