Hi all, I'm a total noob when it comes to chemistry, and would need your help to understand the calculation of EMF for batteries. I have a couple of questions about the calculation for Zinc-Carbon batteries in Wikipedia: http://en.wikipedia.org/wiki/Zinc–carbon_battery I can't manage to get 1.5V as a result... So, here's a couple questions: 1) Anode reaction: Zn(s) → Zn2+(aq) + 2 e- [e° = -1.04 volts] Why -1.04 ? Why not +0.76 like in all the textbooks and other webpages? Like on this page: http://www.ausetute.com.au/calcelemf.html 2) Cathode reaction: 2MnO2(s) + 2 e- + 2NH4Cl(aq) → Mn2O3(s) + 2NH3(aq) + H2O(aq) + 2 Cl- [e° ≈ +.5 v] How to get the 0.5V? Thanks already for your help!