MHT CET Medical202624 April 2026Morning ShiftChemistryThermodynamics (C)Actual
What is the work done in the formation of 1 mole gaseous methane from solid carbon and gaseous hydrogen at 27^ C ? ( R=8.314 J k ⁻¹ mol ⁻¹ )
Options
- A-2.4942 kJ
- B+2.4942 kJ
- C-24.942 kJ
- D+24.942 kJ
Correct answer
B. +2.4942 kJ
Step-by-step solution
The balanced chemical equation for the formation of 1 mole of gaseous methane is: C(s) + 2 H ₂ (g) CH ₄ (g) The change in the number of moles of gaseous substances ( n_g ) is: n_g = n_ g, products - n_ g, reactants n_g = 1 - 2 = -1 The work done ( W ) during a chemical reaction at constant temperature and pressure is given by: W = - n_g R T Given: R = 8.314 J K ⁻¹ mol ⁻¹ T = 27^ C = 27 + 273 = 300 K Substituting the values: W = -(-1) 8.314 300 W = +2494.2 J W = +2.4942 kJ Answer: +2.4942 kJ