1. The problem statement, all variables and given/known data A 0.035 kg ice cube at its melting point is dropped into an insulated container of liquid nitrogen. How much nitrogen evaporates if it is at its boiling point of -196 C? Nitrogen has heat of vaporization of 200000 J/kg Ice's specific heat is 2100 J/kg*C 2. Relevant equations Assuming that all of the ice cube's heat energy is used to heat the nitrogen. Q = m c T = (0.035)(2100)(0- -196) = 14406 J Latent Heat for Nitrogen (H) H = m*L = m*200000 3. The attempt at a solution Since Q = H 14406 = 200000*m m = 0.072 kg This is the correct answer. But what I do not understand is: How do we know for sure that the ice cube will reach a temperature of -196 C? This problem feels incomplete. What if the container of nitrogen had 10^1000000000 kg of nitrogen? What if the nitrogen was at 1 K? Clearly, in some cases, that ice cube will not be able to bring the nitrogen to boil. This is not factored into the solution.