Answer : The volume of gas occupy at a pressure of 18 psi is, 520.8 mL
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex]
or,
[tex]P_1V_1=P_2V_2[/tex]
where,
[tex]P_1[/tex] = initial pressure = 12.5 psi
[tex]P_2[/tex] = final pressure = 18 psi
[tex]V_1[/tex] = initial volume = 750 mL
[tex]V_2[/tex] = final volume = ?
Now put all the given values in the above equation, we get:
[tex]12.5psi\times 750mL=18psi\times V_2[/tex]
[tex]V_2=520.8mL[/tex]
Thus, the volume of gas occupy at a pressure of 18 psi is, 520.8 mL