Calculate the maximum obtainable work at 25 ˚c for the redox reaction below (not balanced) given the standard reduction potentials as follows: al3+(aq) + 3 e– → al(s) e˚ = –1.66 v mg2+(aq) + 2 e– → mg(s) e˚ = –2.37 v

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a