Question

2 moles of an ideal gas is compressed from 5 dm³ to 2 dm³ against a constant external pressure of 5 × 10⁵ N m⁻² at 300 K. Calculate work done in the process.

Options

• 1500 J

• −150 J

• 500 J

• −300 J

Answer 1

1500 J

Explanation:

P_ext = 5 × 10 N m⁻²

= 5 bar

(1 bar = 1 × 10⁵ N m⁻²)

W = −P_ext ΔV

= −P_ext (V₂ − V₁)

= −5 (2 − 5)

= 15 dm³ bar

= 1500 J     (∴ 100 J = 1 dm³ bar)