Kinetic Energy

Kinetic Energy! One of the most abundant forms of energy on earth.

But, wait a minute, shouldn't we be studying this in a physics class?

Nope, actually kinetic energy is very present in chemistry.

Kinetic is the energy of motion. We know that particles are always in movement, thus it will generate energy in the form of movement.

You know how particles' movement influence and is influenced by the temperature temperature change? Well, this is simple to understand if we say that when the temperature increases, the kinetic energy increases as well, and vice versa.

Wait we know what kinetic energy is, but can we measure it?

The answer is no. However, we can measure temperature.

A change in temperature indicates that energy has left or entered a substance. However the amount of energy required to change the temperature of different substance by the same amount, varies with the type of substance. 

For example: It actually take 4.19 J of energy to change the temperature of 1 ml of water by one degree, while it takes 0.897 J of energy to change the temperature of 1 g of aluminium by one degree.

These values quoted above are known as the specific heat of a substance. The amount of energy necessary to increase one gram of a substance by one degree Celsius. 

It is very important to remember that the state of the substance influences its specific heat capacity.

Okay okay, lets not get out of focus here. We know that we can measure temperature. We also know we can be provided the specific heat capacity of a substance. Okay. Now, can we measure the mass of the substance?

If the answer is yes, we can use these three values and form a equation which will provide us the amount of energy that was exchanged.

Q=mc(tf-ti), where Q represents the amount of energy, m is equal to mass, c is equal to specific heat capacity.

Note that if the temperature change is negative, it will make the Q value be negative. Thus, this equation not only provide the amount of heat, but tells you if the reaction released or absorbed energy.