Chemistry Help!! Redox Reactions, Cell Potential, and Electrons Transferred?

Question

Ok. Two Problems. Write balanced redox equations and determine both the cell potential and the number of electrons transferred for the spontaneous redox process that occurs when the following couples are connected.

What are the redox equations, cell potential, and electrons transferred?(for a and b )
a) Ni^2+/Ni + Pb^2+/Pb
b) H^1+/H2 + Al^3+/Al

This is the one that I did...
I was given Cl2/Cl^1- + Br2/Br^1- (as the redox couples)
The equation I made was: Cl2+2Br^1- -> 2Cl^1-+Br2
The cell potential was .27.
And I think electrons transferred was: 2.

I got the answer for the
Ni2+/Ni + Pb2+/Pb
which was
Pb^2+ + Ni -> Pb + Ni^2+
and .10 and 2.
But can't figure out what I did wrong on the: H1+/H2 + Al3+/Al
Right now I have:
2H^1+ + Al -> H2 + Al^3+
(which is wrong)
1.66 for cell potential (which is right)
and:
2 for electrons transferred (also wrong)

Answer 1

Ni + Pb2+ -> Ni2+ + Pb

2Al + 6H+ -> 2Al3+ + 3H2

Answer 2

If a voltmeter is appropriate between the two terminals of the cellular at the same time because it particularly is neither charging nor discharging [ie,now no longer appropriate to distinctive electric powered terminals or gadget] the examining of the voltmeter is the closest regular electric powered ability[emf of the cellular]. Redox 0.5 reaction of SHE => 2H+( aq) +2e =>H2(g) => emf=4.40 4 +/- 0.02V at 25 deg C This quantity of voltage is termed absolute electrode ability. For the calculation of distinctive ability at any temparature SHE ability at that temparature is often taken as 0 as a custom and ability of option electrodes is calculated likewise' To make the redox reaction of SHE ensue platinised platinum electrode is dipped an acidic answer. application of SHE is the ordinary availability of water to function each so usually to maintain the acid optimally diluted. thank you.