Isochoric Process
Definition
Heating or cooling at constant volume — like a sealed pressure cooker: nothing expands, so all the heat becomes internal energy.
Technical definition
V = constant implies W = 0, so Q = ΔU = nCᵥΔT. On a P–V diagram an isochore is a vertical line.
Example
A sealed aerosol can in a hot car: volume fixed, pressure climbs with temperature — which is why the label warns it may burst.
Common confusion
Students mix up isochoric and isobaric. Isochoric = constant VOLUME (think 'chamber'); isobaric = constant PRESSURE. The 'work = 0' shortcut belongs to isochoric.