The pK_a of 2-chloropropanoic acid, CH₃CHClCO₂H, is 2.83. Calculate the Gibbs energy for the dissociation
CH₃CHClCO₂H(aq) + H₂O(aq) ⇌ CH₃CHClCO₂^-(aq) + H₃O⁺(aq)
At a temperature of 298 K.

Question

Quizplus · Accepted Answer

The Gibbs energy for the dissociation can be calculated using the equation:ΔG = -RTlnKwhere R is the gas constant (8.314 J/mol·K), T is the temperature in Kelvin (298 K), and K is the equilibrium constant.The equilibrium constant for the dissociation of 2-chloropropanoic acid can be calculated using the pK_a:pK_a = -logKK = 10^-pK_aK = 10^-2.83 = 1.48 × 10^-3Substituting the values of R, T, and K into the equation for ΔG, we get:ΔG = -8.314 J/mol·K × 298 K × ln(1.48 × 10^-3)ΔG = +16.1 kJ/molTherefore, the correct answer is A: +16.1 kJ mol^-1.

The PKa of 2-Chloropropanoic Acid, CH3CHClCO2H, Is 2

The PK_a of 2-Chloropropanoic Acid, CH₃CHClCO₂H, Is 2