# Question Video: Calculating the Ratio of Gas Volume before and after Heating Using Charles’ Law Physics

A gas is heated while being kept at a constant pressure. If its temperature in kelvins increases by a factor of 2, by what factor does the volume of the gas change?

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### Video Transcript

A gas is heated while being kept at a constant pressure. If its temperature in kelvins increases by a factor of two, by what factor does the volume of the gas change?

The question asks us how the volume of a gas changes when we increase the temperature by a specific amount. To answer this question, Let’s recall Charles’s law. The volume of a fixed amount of an ideal gas is directly proportional to its absolute temperature if the gas is kept at a constant pressure.

Now, we’re told in the question that the gas is kept at a constant pressure. Therefore, it follows the condition for Charles’s law to be applicable here. This means that if we change the temperature 𝑇 of our gas, the volume 𝑉 must change proportionally. What that means is that if we change one of these quantities by some factor, the other would change by the same factor.

In this question, we’ve been told that the temperature of the gas, in kelvins, increases by a factor of two. Due to this direct proportionality relationship, the volume of the gas must therefore also increase by a factor of two. Hence, our final answer is that the volume of the gas increases by a factor of two.