specific heat

Meaning: Specific heat is a property of the material, so it does not depend on how much you have. A substance with high c, such as liquid water, absorbs or releases a lot of energy for a small temperature change. Metals have low c and change temperature quickly. Water's value is about 4.18 J/(g·K), or 1 cal/(g·°C). The idea applies within a single phase. During melting or boiling, added heat changes the phase at constant temperature.

Equation: q = mcΔT, where q is heat transferred (J), m is mass (kg), c is specific heat (J/(kg·K)), and ΔT is the temperature change (K). A change of 1 K equals a change of 1 °C.

On the MCAT: Calorimetry passages drop a hot metal into water. You set heat lost equal to heat gained (m₁c₁ΔT₁ = −m₂c₂ΔT₂) to find the final temperature or an unknown c. On a heating curve of temperature versus heat added, a sloped segment is steeper when mc is smaller. Water's high c also explains milder coastal climates.

Common confusion: Specific heat is not heat capacity (C = mc, in J/K, for a whole object) and not latent heat (q = mL, used during phase changes). Using q = mcΔT on the flat plateau of a heating curve is a classic error. Temperature does not change there, so heat goes into the phase change, not into ΔT.