Calculating Volume Changes using Charles' Law

How can we calculate volume changes using Charles' Law?

If 3.50 moles of He occupy 86.163 L at 300 K and a pressure of 1 atmosphere, what will the volume be for 3.50 moles at 250 K and 1 atmosphere?

Answer:

The final volume will be 71.8 L

Charles' Law is used to calculate volume changes of a gas at constant pressure when the temperature is altered. It states that the volume of a gas is directly proportional to its temperature.

To calculate the final volume of helium at 250 K, we can use the formula:

[tex]\frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex]

Given values:

Initial volume (V₁) = 86.163 L

Initial temperature (T₁) = 300 K

Final temperature (T₂) = 250 K

We need to find the final volume (V₂).

By substituting the values into the formula and solving for V₂:

[tex]\frac{86.163 L}{300 K} = \frac{V_2}{250 K}[/tex]

Calculating gives us:

[tex]V_2 = \frac{86.163 \times 250}{300}[/tex]

Therefore, the final volume will be 71.8 L when the temperature is reduced to 250 K.