Answer: The final pressure is 75 mm Hg.
Explanation:
According to Boyle's law, at constant temperature the pressure of a gas in inversely proportional to volume.
Since, it is given that the temperature is constant. Hence, formula used is as follows.
[tex]P_{1}V_{1} = P_{2}V_{2}[/tex]
Substitute the values into above formula as follows.
[tex]P_{1}V_{1} = P_{2}V_{2}\\750 mm Hg \times 2 L = P_{2} \times 20 L\\P_{2} = \frac{750 mm Hg \times 2 L}{20 L}\\= 75 mm Hg[/tex]
Thus, we can conclude that the final pressure is 75 mm Hg.