Answer
a. The reaction is an oxidation-reduction reaction because here Zn is being oxidized and Co is getting reduced and their oxidation numbers changed from 0 to +2 and from +2 to 0 respectively.
b. This is not a redox reaction as no electrons are transferred.
c. This is not a redox reaction as no electrons are transferred.
d. The reaction is an oxidation-reduction reaction because here K is being oxidized and Br is getting reduced and their oxidation numbers changed from 0 to +1 and from 0 to -1 respectively.
Work Step by Step
a. The reaction is an oxidation-reduction reaction because here Zn is being oxidized and Co is getting reduced and their oxidation numbers changed from 0 to +2 and from +2 to 0 respectively.
b. This is not a redox reaction as no electrons are transferred.
c. This is not a redox reaction as no electrons are transferred.
d. The reaction is an oxidation-reduction reaction because here K is being oxidized and Br is getting reduced and their oxidation numbers changed from 0 to +1 and from 0 to -1 respectively.