Gibbs free energy problem please help!?
A solution of Cu (2+) is 2.2x10^-10M when the pH is held at 9.00. The temperature is 22 degrees C. What is ΔG° for the reaction Cu(2+)(aq) + 2OH (1-)(aq) <=> Cu(OH)2(s)
Formulas to choose from:
ΔG=ΔG° + RT ln (Q) (Q is the reaction quotient, R=8.314 J/molxK)
ΔG°= -RT ln(K) (K is the equilibrium constant)
That's all the information I had available on the test. I want to learn from my mistakes!
Answers & Comments
Verified answer
This was answered recently, I've pasted that answer here.
Cu²⁺ + 2 OH⁻ ⇌ Cu(OH)₂(s)
At equilibrium [Cu²⁺] = 2.2 × 10⁻¹⁰ ; [H₃O⁺] = 10⁻⁹ ⇒ [OH⁻] = 10⁻⁵
K_eq = 1/[Cu²⁺][OH⁻]² = 1/(2.2 × 10⁻¹⁰)(10⁻⁵)² = 1/(2.2 × 10⁻²⁰) = 4.55 × 10¹⁹
∆G°(295) = –(8.314 J/mol•K)(295 K)ln(4.55 × 10¹⁹) = –111.07 kJ/mol