How do you calculate the theoretical cell voltage?

Question

1) Zn|Zn^+2 | Cu|Cu^+2
2) Cu|Cu^+2 | Zn|Zn^+2
3) Fe|Fe^+2 | Cu|Cu^+2
4) Zn|Zn^+2 | Cu|Cu^+2
5) Cu|Cu^+2 | Cu|Cu^+2

Answer 1

http://www.ausetute.com.au/calcelemf.html

Answer 2

but for example for question 4 Zn is 1 M and Cu is 0.1 M will that make a difference? and can you just do one example I want to see if I'm on the right track. Thanks.