Question

Hot Steel; Cold Ice: A 36.0 g block of ice sits at −50.0 °C under 1.00 atm constant pressure in a perfectly insulated container. A 225 g mass of stainless steel at 125 °C is dropped onto the ice, and the system is closed. When the system reaches thermal equilibrium, ice remains.

Which statement best describes the relationship between q_steel and q_water for this particular system?

A. q_steel and q_water are the same value that is greater than zero.
B. q_steel and q_water are both zero since the container -- a perfectly insulated container -- transfers no heat to the surroundings.
C. q_steel and q_water are unrelated since there is both solid and liquid water present.
D. q_steel and q_water have the same magnitude, but are opposite in sign.

Answer 1

The hot steel gives heat (-q) to the ICE (not the water) (+q) . That melts some, but not all, of the ice. Since there is ice left in the end, all three, steel, water, and ice are at exactly 0 deg C. NO heat went into the water. It stayed at 0 C after melting.