Here's my problem A box with the heathcapacity 80J/K contains 0,2kg water. The box and the water has together the temperatur 18*C. We put 0,050kg ice with the temperature -15*C in the box of water. Investigate if all ice melts. Don't take with heath from the surrondings. Well for this problem I though like this 0,2Kg Water * 4,19(water's heath capacity) = 0,838 + 80J/K =0,8380008 Then I took the Ice capacity = 0,050kg * 4,19 = 0,2095 0,8380008-0,2095 =0,62858 Then lets do it to Kelvin 273+18=291K 273-15=258K 0,62858 * -33 K = -20,7314 But that doesn't say me nothing if the Ice has melted? How do I know that?