Question

Calculate the work done in kJ in a reaction if the volume of the reactant decreases from 8 dm³ to 4 dm³ against 43 bar pressure.

[1 dm³ bar = 100 J]

Answer 1

Given:

Initial volume (V₁) = 8 dm³

Final volume (V₂) = 8 dm³

External pressure (P) = 43 bar

Conversion factor = 1 dm³ bar = 100 J

Formula:

W = −PΔV

Where, ΔV = V₂ − V₁

ΔV = 4 − 8 = −4 dm³

W = −(43 × −4)

W = 172 dm³ bar

Since 1 dm³ bar = 100 J

W = 172 × 100

W = 17200 J

W = 17.2 kJ

∴ The work done in the reaction is 17.2 kJ.