posted by Tiffany on .
The specific heat of solid copper is 0.385 J/g*C. What thermal energy change occurs when the temperature of a 40.10g sample of copper is cooled from 42.9C to 10.0C? Be sure to give you answer the proper sign.
I know this is part of the answer which
(42.9-10.0)*40.10*0.385=508 the second of the answer is where I am confused on
This is amount of heat is used to melt solid ice at 0.0C. The molar heat of fusion of ice is 6.00 kJ/mol. How many moles of ice are melted?
I use q = mass x specific heat x (Tfinal-Tinitial) which automatically takes care of the sign. Since the Cu is being cooled, it is giving off heat and that makes q negative. The problem states that proper sign should be used so I would make that -508 J.
mols ice x 6.00 kJ/mol = 0.508
Solve for mols ice.