MHT CET2016ChemistryThermodynamics (C)
What is the amount of work done when 0.5 mole of methane, C H 4 g is subjected to combustion at 300 K? (Given, R = 8.314 J K - 1 m o l - 1 )
Options
- A- 2494 J
- B- 4988 J
- C+ 4988 J
- D+2494 J
Correct answer
D. +2494 J
Step-by-step solution
C H 4 ( g ) + 2 O 2 ( g ) → C O 2 ( g ) + 2 H 2 O ( l ) Amount of work done = - ∆ n R T 1 mole of methane reacts with 2 moles of oxygen to produce 2 moles of C O 2 Hence, 0.5 mole of C H 4 reacts with 1 mole of O 2 to produce 1 mole of C O 2 . ∴ n 1 = moles of reactants = 1.5 n 2 = moles of product = 1 ∴ ∆ n = n 2 - n 1 = 1 - 1.5 = - 0.5 w = - - 0.5 × 300 × 8.314 J K - 1 m o l - 1 = + 2494 J