Question

If the volume of a confined gas is doubled, while the temperature remains constant, what change (if any) would be observed in the pressure?A. it would be half as largeB. it would doubleC. it would be 4 times as largeD. it would remain the same

Answer 1

Answer: Option (A) is the correct answer.

Explanation:

According to the ideal gas law, the formula is as follows.

                        PV = nRT

And, when the temperature is constant then,  

               PV = constant

This means that P is inversely proportional to V in this case . Therefore, if the volume is doubled than pressure would be half as large.

Mathematically,     $\frac{P_{1}}{P_{2}} = \frac{V_{2}}{V_{1}}$

                 $P_{2} = \frac{P_{1} \times V_{1}}{V_{2}}$

                         $V_{2} = 2 \times V_{1}$

              $P_{2} = \frac{P_{1} \times V_{1}}{2 \times V_{1}}$

                       = $\frac{P_{1}}{2}$

This means that $P_{2} = \frac{1}{2} \times P_{1}$

Thus, we can conclude that if the volume of a confined gas is doubled, while the temperature remains constant, then pressure would be half as large.