Heat
Heat for heating and cooling, melting, boiling and burning fuel, and the heat balance of a mixture, with tables of substances.
What to find:
Specific heat, latent heats and heats of combustion are taken from school textbook tables. Temperatures are in degrees Celsius.
The heat calculator solves problems on heating and cooling, melting, boiling, burning fuel and heat balance. Specific heats and latent heats come from school textbook tables.
Formulas
| Process | Formula |
|---|---|
| heating, cooling | Q = mc(t2 − t1) |
| melting, freezing | Q = mLf |
| boiling, condensation | Q = mLv |
| burning fuel | Q = qm |
Example. Heating 2 kg of water from 20 to 100 °C takes Q = 4200 · 2 · 80 = 672,000 J = 672 kJ.
Heat balance
When a hot and a cold body are mixed, the hot one gives off as much heat as the cold one receives:
c1m1(t1 − t) = c2m2(t − t2)
Mixing 2 kg of water at 80 °C with 3 kg at 20 °C gives t = (2 · 80 + 3 · 20) / 5 = 44 °C.
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