Question

how can you tell if something with oxidize or reduce some other thing, based on the standard reduction potential table?

Answer 1

X^+ + e ==> X Ered = -1.5v
Y^+ + e ==> Y Ered = -1.0v
So X will be oxidized and y^+ will be reduced because
X ==> X^+ + e Eox = 1.5v
Y^+ + e ==> Y Ered = -1.0v
----------------------------
X + Y^+ ==> X^+ + Y Ecell = +0.5

You can see that the rxn with the more negative number wants to "go the other way" which means X will reduce Y^+ or Y^+ will oxidize X.