Heating curves and combined energy steps

Break a heating process into distinct stages. On a sloping section of a temperature–time graph, use Q= mcΔT if the sample remains in one state. On a plateau at a phase transition, use Q=mL. Add the energies for a multistage process. A time interval on its own is not a temperature change; check which axis is horizontal before reading a slope.

For constant absorbed power P, each stage takes t=PQ​. A larger heat capacity gives a shallower temperature–time slope because dtdT​=mcP​. A longer phase-change plateau means more absorbed energy if power is unchanged. State whether the model neglects energy absorbed by the container and energy escaping to the surroundings; these terms alter the relation between electrical input and sample energy.

Watch out: Separate warming and phase-change stages; the phase-change energy is mL and is not included by a zero ΔT.