In the equation q = m c ΔT, which term represents the temperature change?

• A. ΔT
• B. q
• C. c
• D. m

Answer: (A)

The temperature change is represented by ΔT, which is the difference between the final and initial temperatures. In q = m c ΔT, ΔT tells you how much the temperature actually changes when heat is added or removed. The other symbols describe what that heat does: q is the heat energy transferred, m is the mass, and c is the specific heat capacity, which tells how much energy is needed to raise the temperature of a unit mass by one degree. For example, if a sample warms from 25°C to 45°C, ΔT = 20°C (or 20 K), and the heat required is q = m c (20°C). Since ΔT is a change, its units can be °C or K, with the numerical value the same.