Calculate the work done in kJ in a reaction, if volume of the reactant decreases from 8 dm3 to 4 dm3 against 43 bar pressure. [ 1 dm3. bar = 100J ]

Q.8 Calculate the work done in kJ in a reaction, if volume of the reactant decreases from 8 dm³ to 4 dm³ against 43 bar pressure. [ 1 dm³. bar = 100J ]

Doubtly Asked 28 Oct 2026 Board exam · March 2025 hsc 12th Save WhatsApp Report

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Answer: W = +17.2 kJ (work is done on the system)

\(W = -P_{ext}\Delta V = -P_{ext}(V_2 - V_1)\)

\(= -43\ \text{bar} \times (4 - 8)\ \text{dm}^3 = +172\ \text{dm}^3\,\text{bar}\)

\(= 172 \times 100\ \text{J} = 17200\ \text{J} = 17.2\ \text{kJ}\)

The positive sign shows that work is done on the system (compression).

Doubtly AI · 28 Oct 2026 AI-verified · Oct 2026 Report

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Calculate the work done in kJ in a reaction, if volume of the reactant decreases from 8 dm3 to 4 dm3 against 43 bar pressure. [ 1 dm3. bar = 100J ]

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