Specific Heat Capacity Flashcards

All 6 cards in this deck

What is the specific heat capacity of a substance?

The amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius. Unit: J/kg °C.

What three things determine how much the temperature of a substance rises when it is heated?

The mass of the substance, the type of material (its specific heat capacity) and the energy input.

What is the equation linking energy, mass, specific heat capacity and temperature change?

$\Delta E = mc\Delta\theta$ (energy = mass × specific heat capacity × temperature change)

What are the steps to calculate the energy needed to change a substance's temperature?

e.g. heat 3 kg of water by 10 °C, $c = 4200$ J/kg °C

1. Write $\Delta E = mc\Delta\theta$, mass in kg.
2. Substitute: $\Delta E = 3 \times 4200 \times 10$
3. Evaluate: $\Delta E = 126\,000$ J

What are the steps to find a specific heat capacity from measurements?

e.g. 8400 J raises the temperature of 2 kg of a liquid by 1 °C

1. Write $\Delta E = mc\Delta\theta$.
2. Rearrange: $c = \dfrac{\Delta E}{m\Delta\theta}$
3. Substitute: $c = \dfrac{8400}{2 \times 1} = 4200$ J/kg °C

True or false? In $\Delta E = mc\Delta\theta$ the mass must be converted into kilograms.

True. Masses given in grams must be divided by 1000 before substituting.