Answer : The final volume of the sample of gas is, 120 mL
Explanation :
According to the Boyle's law, the pressure of the gas is inversely proportional to the volume of gas at constant temperature and moles of gas.
![P\propto (1)/(V)](https://img.qammunity.org/2021/formulas/physics/high-school/c8nvqpp73572vgqfzr0w0zxo0bkzz86byp.png)
or,
![P_1V_1=P_2V_2](https://img.qammunity.org/2021/formulas/physics/high-school/z2nkrx5zmdtkkms997yjs4edj5t3o0sadf.png)
where,
= initial pressure = 1.5 atm
= final pressure = 5 atm
= initial volume = 400 mL
= final volume = ?
Now put all the given values in the above formula, we get:
![1.5atm* 400mL=5atm* V_2](https://img.qammunity.org/2021/formulas/chemistry/college/lax6x2y5pfzu1qhhxiy5czuefoajocq3gu.png)
![V_2=120mL](https://img.qammunity.org/2021/formulas/chemistry/college/f4brxap4rg0zf5k5ihncouleo34wr5v949.png)
Therefore, the final volume of the sample of gas is, 120 mL