Specific & Latent Heat

Q = m·c·ΔT: the energy to change a mass by a temperature difference, with c the specific heat capacity in J/(kg·K). A change of one kelvin equals a change of one degree Celsius, so ΔT is the same number either way. The page solves the equation for whichever of the four you leave out, which makes it both a "how much energy" tool and a calorimetry tool: heat a sample with a known energy, measure the rise, and read off its specific heat.

Q = m·L: the energy a phase change takes at constant temperature, with L the latent heat of fusion (melting) or vaporisation (boiling). All of that energy goes into breaking bonds rather than raising the temperature, so a thermometer in the mixture reads the transition temperature until the change is complete. The numbers are large — boiling water away takes about five times the energy of heating it from freezing to boiling — which is why steam burns are so much worse than hot-water burns and why sweating cools so effectively.

Heating something through a phase change is three stages: m·c·ΔT to the transition, m·L for the change, then m·c·ΔT beyond it with the new phase's capacity (steam's is about half liquid water's, so both are asked for). No material table is stored: c and L come from your data sheet, because c varies with temperature and, for gases, with whether pressure or volume is held constant. The heating time assumes the power reaches the material at the efficiency you give, with no loss to the surroundings — real kettles, pots and furnaces lose more. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.