I must be doing something wrong here but I cannot figure out what it is 1. The problem statement, all variables and given/known data An insulated beaker with negligible mass contains a mass of 0.350kg of water at a temperature of 70.1∘C. How many kilograms of ice at a temperature of − 11.6∘C must be dropped in the water to make the final temperature of the system 25.0∘C? Take the specific heat for water to be 4190J/(kg⋅K) , the specific heat for ice to be 2100J/(kg⋅K) , and the heat of fusion for water to be 334kJ/kg . 2. Relevant equations Q = mcT Q = mcT + Lfm 3. The attempt at a solution So basically I was just doing... mwcw ΔTw = mi [(ci ΔTi) + Lf i] which gives ΔTw = 70.1∘C. - 25∘C = 45.1K ΔTi = − 11.6∘C - 25∘C = 36.6K 0.350kg * 4190J/(kg⋅K) * (45.1K) = mi [(2100J/(kg⋅K)*(36.6K)] +334kJ/kg] 66139.15J = 257140J/kg * mi mi = 0.161kg which does not turn out to be the right answer (I do not have access to the right answer). Can anyone tell me what mistake I am making. Any help would be greatly appreciated.