Question 22

[jwmenard3521]

for Eo, when you reverse the direction don't the sign also get reversed? i.e- Eo=+1.36 for reduction of Cl2. for oxidation of Cl2 wouldn't Eo=-1.36?
thanks

[jellywing_2058]

Well yes and no. The Eo's given are the standard reduction potentials. The formula you are asked to know is Eo(cell)= Eo(reduction)- Eo(oxidation). For this formula, you always use the standard reduction potential (a.k.a. the numbers given in the question) without ever touching the signs. So when in the formula we say Eo(oxidation) we actually mean the Eo(reduction) of the oxidation equation.

If you had been given the standard oxidation potential for one of the equations, then you could either switch the sign of that Eo OR do Eo(cell)=Eo(reduction)+ Eo(OXIDATION).