The standard reduction potentials for Zn
2+ / Zn, Ni2+ / Ni, and Fe
2+ / Fe are –0.76, – 0.23 and
–0.44 V respectively. The reaction X + Y2+ -- X2+ + Y will be spontaneous when :
(1) X = Ni, Y = Zn (2) X = Fe, Y = Zn (3) X = Zn, Y = Ni (4) X = Ni, Y = Fe

Question

The standard reduction potentials for Zn
2+ / Zn, Ni2+ / Ni, and Fe
2+ / Fe are –0.76, – 0.23 and
–0.44 V respectively. The reaction X + Y2+  --> X2+  +   Y will be spontaneous when :
(1) X = Ni, Y = Zn (2) X = Fe, Y = Zn (3) X = Zn, Y = Ni (4) X = Ni, Y = Fe

jfraser · Answer

a redox reaction will be spontaneous when $E^0$ is greater than zero, correct?

and we calculate $E^0$ by using $$E^0 = E^0_{red} - E^0_{ox}$$

priyar · Answer

@JFraser yes, i know that my answer is (3).. i decided based on the reduction and oxidation potentials. is it correct?

priyar · Answer

@ParthKohli @ganeshie8

priyar · Answer

@Cuanchi

priyar · Answer

@Vincent-Lyon.Fr

priyar · Answer

@Kainui

parthkohli · Answer

You want the situation to be such that...
1. X is the most desperate to be oxidised
2. Y is the most desperate to be reduced

We see that Zn wants to be oxidised the most and Ni2+ wants to be reduced the most out of all.
X = Zn, Y = Ni.

priyar · Answer

@Parthkohli in other words my answer is correct..?

parthkohli · Answer

I'd say so, yeah.

priyar · Answer

but the book doesn't agree.. so are you sure?

parthkohli · Answer

I am...

priyar · Answer

okay thats why i asked this Q.. just to confirm.. Thanks