Consider the chemical reactions represented by the cells diagrams. Which one of
ID: 522718 • Letter: C
Question
Consider the chemical reactions represented by the cells diagrams. Which one of following these reactions will proceed spontaneously as written? The temperature is 25 degree C. A) Cu(s) | Cu^2+ (aq, 1M) || H_2(g, 1 atm), H^+(aq, 1 M) | Pt(s) B) C(s, graphite) | Sn^2+ (aq, 1 M), Sn^4+ (aq, 1M) || Pb^2+ (aq, 1 M) | Pb(s) C) Zn(s) | Zn^2+ (aq, 0.1 M) | Zn(s) D) Cu(s) | Cu^2+ (aq, 1 M) || Ag^+ (aq, 1 M) | Ag(s) E) Ag(s) | Ag^+(aq, 1M) || Ni^2+ (aq, 1 M) | Ni(s) Two graphite electrodes are immersed into a 1 M solution of ZnBr_2 in 1 M HBr_2 and a potential difference of 2.0 V is applied. If the overpotential is ignored, which one of the following species is most likely to be produced at the cathode?Explanation / Answer
in order for a reaction to be spontaneous, the E cell must be postivie
so
a)
Cupper reduction > Hydrogen, this is NOT spontaneous
b)
Sn4+ + 2 e Sn2+ +0.15
Pb2+ + 2 e Pb(s) 0.126
Lead will actually oxidize, therefore this is NOT spotnaneous
c)
Q = [Zn ]anode / [Zn ] cathode
Q = (0.1)/(1) = 0.1
this is spontaneous
d)
This is spontaneous as written
e)
Silver potential > Nickel, will not occur