Question

How do you calculate specific heat capacity given heat flow, mass and temperature change?

Answer 1

To calculate the specific heat capacity of a substance, use the formula `Q = m C Delta T`

where Q is the quantity of heat (energy) needed to raise the temperature of 1 kg of a substance by 1°C, measured in J;
m is the mass of the substance, in kg;
C is the specific heat capacity of the material, in `J/(kg * °C)`; and
`Delta T` is the temperature change, in °C.

If you are looking for the specific heat capacity (C), you will need to isolate it by dividing both sides by `m Delta T`.

Example:

`2.34 \times 10^4` J of heat are added to 2.0 kg of an unknown metal to cause a temperature change of `90.0° C`. What is the specific heat capacity of the unknown metal?

`C = Q / (m Delta T)`
`C = (2.34 \times 10^4 J) / (2.0 kg \times 90.0° C)`
`C = 1.30 \times 10^2 J/(kg * °C)`

You can easily look up on a chart of specific heat capacities this value, to find that this metal is (most likely) lead.