"A 6.00 kg piece of solid copper metal at an initial temperature T
is placed with 2.00 kg of ice that is initially at -20.0°C. The ice is in an
insulated container of negligible mass and no heat is exchanged with the
surroundings. After thermal equilibrium is reached, there is 1.20 kg of
ice and 0.80 kg of liquid water. What was the initial temperature of the
piece of copper?"
this is the problem.
in the Qgain = m_ice * c_ice * temp_ice + m_water * L (334*10^3)
but why mass of water in the formula Q=mL
i thought ice is gaining heat and melting to water so shouldn't it be mass of ice?
Best Answer
In the equation $Q=mL$, note that $L$ is the latent heat of fusion, or the energy required to change the state of a solid (in this case, ice) to a liquid (water). Here, 0.8 kg of ice has changed phase to water.
So it makes sense that the mass of the ice appears in the equation.