Chemistry 30 Thermodynamics: Law of Conservation of Energy

1.2 The Law of Conservation of Energy

One of the key principles of chemistry is the Law of Conservation of Energy:

Law of Conservation
of Energy

During physical and chemical processes, energy may change from one form to another but it may not be created or destroyed.

Also known as the
First Law of Thermodynamics

To give a few examples of how energy is converted from one form to another:

When octane (C₃H₈, the main component of gasoline) is burned in your car engine, chemical bond energy (potential energy) is converted into mechanical energy (pistons moving in the car engine; kinetic energy) and heat.

When we eat, our bodies convert the chemical energy of the food into movement of our muscles; again heat is also a product of this conversion.

When we turn on a light switch, electrical energy is converted into light energy and, you guessed it, heat energy.

As we continue with this lesson we will be discussing how energy changes during chemical reactions. Often the energy change involves a conversion between potential energy and kinetic energy (as heat). You'll want to understand that the energy you see represented in chemical equations does have a source - potential energy - and is not created out of nothing.

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Thermodynamics

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1.2 The Law of Conservation of Energy

Law of Conservation
of Energy