Q = heat

c = specific heat capacity

m = mass

= temperature variation

 

 

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Energy - Intro

Potential Energy

Kinetic energy

Chemical energy: enthalpy

Heat energy

Electric energy

Nuclear Energy

Power stations

Conservation of Energy

 

Specific heat capacity of gases

Advanced topic: The specific heat capacity of gases

The relationship between temperature and kinetic energy can be more easily visualized in the case of gases:

 

Cooler gas (lower kinetic energy):

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Hotter gas (higher kinetic energy):

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The blue balls represent an atom (in a monatomic gas, like He) or a molecule in a gas like water vapour or oxygen.

Note that gas atoms/molecules are in reality much faster than the particles above, and also much more numerous.

When you heat a gas, the heat energy provided is converted into kinetic energy of its particles.

However, if your gas is not monoatomic, the energy supplied will also be converted into vibrations and rotations .Molecules are never steady; they always vibrate and rotate. So, because part of the energy is converted in vibrational and rotational energy, less energy is left to be converted into kinetic energy. Because temperature is a measure of the kinetic energy, a smaller increase of temperature is recorded for a molecular gas that receives heat (when compare to the monoatomic gas).

It is like leaving with 2 friends that don't have any money: the food you buy will be consumed equally by 3 people, so that you only get a third of the amount you got in the first place!

Finally is also true that, like in the case of solids, heavier gases will tend to have a higher specific heat capacity than lighter gases.

Examples of calculations involving heat and temperature>>

 

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