Question
Chemistry Question on Equilibrium
Using the Gibbs energy change, ΔG∘=+63.3kJ , for the following reaction, Ag2CO3⇌2Ag(aq)++CO3(aq)2− the Ksp of Ag2CO3(s) in water at 25∘C is (R=8.314JK−1mol−1)
A
3.2×10−26
B
8.0×10−12
C
2.9×10−3
D
7.9×10−2
Answer
8.0×10−12
Explanation
Solution
ΔG∘ is related to Ksp by the equation
ΔG∘=−2.303RTlogKsp
Given, ΔG∘=+63.3KJ
=63.3×103J
Thus, substitute ΔG∘=63.3×103J,
R=8.314JK−1mol−1 and T= 298 K [25 + 273 K]
from the above equation to get
63.3×103=−2.303×8.314×298logKsp
∴logKsp=−11.09
⇒Ksp=antilog(−11.09)
Ksp=8.0×10−12