Calculate the heat energy released when 19.6 of liquid mercury at 25.00 C is converted to solid mercury at its melting point

Answer 1

There are only two equations to remember in this heat transfer business with specific heat.
1. q= heat absorbed/releassed by phase change (melting/condensing) = mass x heat fusion for melting/freezing or heat vaporization for vaporization/condensing.
2. heat change by moving T higher or lower within the same phase.
q = mass x specific heat x (Tfinal-Tinitial).
Knowing these two you can move from "anywhere" to "anywhere". For Hg,
q1 = heat lost changing T from 25C for liquid Hg to a liquid at its freezing point.
q2 = heat lost when liquid Hg freezes to solid Hg.
Then add q1 to q2.