1. The problem statement, all variables and given/known data A 25 g glass tumbler contains 350 mL of water at 24°C. If four 20 g ice cubes each at a temperature of -3°C are dropped into the tumbler, what is the final temperature of the drink? Neglect thermal conduction between the tumbler and the room. 2. Relevant equations Q = mcT Q = mLf (energy required to melt a substance of mass m) 3. The attempt at a solution Here are all the known variables: massw = .35kg c (specific heat for water) = 4186 J/kg * C Twater,initial = 24 C massice = 4*20g = .08kg Lf = 3.33*105 J/kg Tice,initial = -3 C Tf = ? First I can use Q = mcT to see if all the ice will get melted by the water Q = (.35kg)*(4186 J/kgC)*(24C) = 35162.4 J m = Q/Lf = (35162.4 J) / (3.33*105 J/kg) = .105592 Since the total mass of the ice is .08, then all the ice will get melted. Now we can apply conservation of energy to find the final temperature. massw*c*(Twater,initial - Tf) = massice*Lf + massice*c*(Tf-Tice,initial) Plugging in all my variables and solving I get 4.18 C which is incorrect. My math could be wrong but I don't believe it is. Could anyone provide any insight on what I am doing wrong?