Question

What would the volume of the gas be if the pressure is increased to 40 psi?
in.3

Answer 1

I’m missing the initial pressure and volume (and whether the temperature stays constant). If this is an isothermal change for a fixed mass of gas, use Boyle’s law:

P1 · V1 = P2 · V2 → V2 = P1 · V1 / P2

Notes:
- Pressures must be absolute (psia), not gauge (psig). Convert by adding atmospheric pressure ≈ 14.7 psi: P_abs = P_gauge + 14.7 psi.
- The result will be in the same volume units you use for V1 (e.g., in³).

If you give P1 and V1 I’ll compute V2. Example: if P1 = 30 psi (gauge) and V1 = 120 in³, and P2 = 40 psi (gauge):

P1_abs = 30 + 14.7 = 44.7 psia
P2_abs = 40 + 14.7 = 54.7 psia
V2 = 44.7·120 / 54.7 ≈ 98.1 in³

Provide your P1 and V1 (and whether temperature is constant) and I’ll calculate the exact result.