Entrance Exams
Govt. Exams
E°cell = E°cathode - E°anode = 0.34 - (-0.76) = 1.10 V. Cu is cathode (reduction), Zn is anode (oxidation).
Increasing pressure favours the direction with fewer moles of gas. For 2NO₂ ⇌ N₂O₄, it favours forward reaction (correct), but statement A is incomplete without specifying the reaction.
For this reaction, Δn = 1 - 2 = -1, so Kp = Kc(RT)^Δn = Kc(RT)⁻¹ = Kc/(RT).
ΔG° = -nFE°cell. For n=2 (typical): ΔG° = -2 × 96500 × 0.34 = -65,620 J/mol ≈ -65.6 kJ/mol.
Henry's law constant for CO₂ in water at 25°C is Kh ≈ 1.67 × 10³ atm·L/mol, used as P = Kh·x.
For isothermal process: W = nRT ln(Vf/Vi). Since Vf > Vi, work done by gas is positive.
Using Arrhenius equation: ln(k₂/k₁) = (Ea/R)(1/T₁ - 1/T₂) = (60000/8.314)(1/298 - 1/348) ≈ 4.63, so k₂/k₁ ≈ 103.
At the critical point, Z = PcVc/RTc = 0.27 for most real gases (theoretical value for van der Waals gas).