Consider the reaction: Au3+ (aq) + 3 Tl (s) ? Au(s) + 3 Tl+ (aq) with Ecell O =
ID: 615086 • Letter: C
Question
Consider the reaction: Au3+ (aq) + 3 Tl (s) ? Au(s) + 3 Tl+ (aq) with Ecell O = +1.84 V. If the reaction occurred at 25 OC, determine the value of the equilibrium constant (K) at this temperature.Explanation / Answer
For parts A & B, see http://www.enotes.com/chemistry/q-and-a/consider-galvanic-cell-based-following-half-333659 Please note that when you post a question, it should only include *one* question. Dividing it into parts A-C does not make it one question :) For part C, we need to calculate Ecell under non-standard conditions Ecell = Eocell - 0.0592/n log Q We know Eocell and have 1.84V (see link above). To find Q, we have to first write the balanced equation Au3+(aq) + 3Tl(s) --> Au(s) + 3Tl+(aq) We need the 3s in front of Tl and Tl+ so that the number of electrons in each reaction is the same so that they will cancel out. Now, we can find Q Q = [Tl+]^3 / [Au3+] Q = (1x10^-4)^3 / 1x10^-2 Q = 1 x 10^-10 Now we can solve for Ecell Ecell = 1.84 - (0.0592/3) log (1 x 10^-10) Ecell = 2.04 V If we increase the concentration of Au3+, then the value of Q will decrease and the log of the value will also decrease. As a result, the second term will have a greater magnitude so the Ecell will increase because we are substracting a negative term.