MEDIUMMCQ SINGLEIChO (Chemistry Olympiad)Physical ChemistryThermodynamics and ThermochemistryPrevious Year Questions
An ideal gas expands isothermally from 10–3 m3 to 10–2 m3 at 300 K against a constant pressure of 105 N m–2. The work done on the gas is (Odisha NEET 2019)
A.+270 kJ
B.–900 J✓ Correct
C.+900 kJ
D.–900 kJ
Explanation
w = –PdV = –P(V₂ – V₁) = –105 N m–2 (10–2 – 10–3) m3 = –105 N m–2 (9 × 10–3) m3 = –9 × 102 N m = –900 J (∴ 1 J = 1 N m)