Question

Given answer is option 'C', but why option 'A' is incorrect ??​

Answer 1

Answer:

Hi dear,

Just remember, whenever a substance is oxidizing something, it should get reduced and if it is reducing something, it should get oxidized.

So, As in 'C' option, it is given that Zn reduces Ag⁺ and Cu⁺²

=> Zn has oxidation state 0 and it is reducing Ag⁺ and Cu⁺². Ag and Cu has +1 and +2 respectively

So, Zn will get oxidized to Zn⁺² and Ag⁺ and Cu⁺² will be reduced to Ag and Cu

Now, in 'A; option, it is given that Ag can oxidize Zn and Cu

If Ag should oxidize something, it should be reduced. Ag is already in 0 oxidation state. Ag cannot have negative oxidation state. But if it will oxidize, it will have to reduce to negative oxidation state which is a contradictory. So, option 'A' is incorrect.

'A' would be correct, if 'Ag⁺ can oxidize Zn and Cu'

[If possible do this problems with this logic, if u get confused with potentials. First thing is that, check all the options with potentials. If u have doubt in 1 or 2 options, follow this method. This is helpful only to find whether it should be a metal or an ion, as this doesn't use potentials. Main preference should be potentials. Do not do this method directly]

Hope it helps!