The specific heat capacity is the amount of thermal energy (Q) needed to raise a mass (kg) by a temperature ΔT by the formula:

$$Q = mcΔT$$Specific heat is a measure of how much thermal energy is needed to raise a mass's temperature. Each material has its own characteristics, so has a unique specific heat capacity.

The symbol for specific heat is 'c', and has the unit J kg^{-1} K^{-1}

The amount of thermal energy required to raise the temperature of a mass m and specific heat capcity c, by a temperature ΔT is:

Q = mcΔT

this formula does assume that c will not change with temperature.

If the thermal energy causes the substance to change state, c may change as a result. e.g. The specific heats of:

- water is 4.186 J/g-K
- ice 2.108 J/g-K
- water vapour 1.996 J/g-K

Latent heat is often used in the calculation of the thermal energy required to cause a change of state: latent heat of fusion (melting) and latent heat of vaporization (boiling).

The symbol of latent heat is L.

L = Q/m

The latent heat of fusion of copper is: L_{f} = 200 kJ kg^{-1}

Question: how much energy would it take to melt 100g of ice which is currently at -10 °C?

Solution: ΔT = 10 K. This will bring the ice block to zero degrees celcius.

Q = mcΔT = (100g) . (4.186 J/g-K) . 10 K = 4186 J

Question: how much power is required to melt one tonne of copper?

Solution: The latent heat of fusion of copper is L_{f} = 200 kJ kg^{-1}

Q = L_{f}.m = 200 kJ kg^{-1} . 1000 kg = 2.0 x 10^{5} kJ = 200 MJ.

The power required is 200 MW-s, or 55 kWh.

Content © Renewable-Media.com. All rights reserved. Created : December 18, 2013 Last updated :February 14, 2016

The most recent article is:

View this item in the topic:

and many more articles in the subject:

Environmental Science is the most important of all sciences. As the world enters a phase of climate change, unprecedented biodiversity loss, pollution and human population growth, the management of our environment is vital for our futures. Learn about Environmental Science on ScienceLibrary.info.

1902 - 1984

Paul Dirac is a leading figure in 20th century physics. His Dirac Equation describes fermions and predicted the existence of anti-matter, winning him a Nobel Prize in 1933.

Website © renewable-media.com | Designed by: Andrew Bone