The molar heat capacity at constant pressure for CO₂ (gas) is 37.1 J/mol·K. Calculate q when 2 moles of CO₂ expand irreversibly from 1 L to 2 L at 1 atm.
Correct: A
Irreversible work is -PΔV. Heat q = nCpΔT from ΔT = (PΔV)/nR = (101.325 kPa)(2-1)L/(8.314 × 2). Calculations yield q ≈ 74.2 J.