Did an oxidation-reduction reaction occur in the reaction between copper sulfate and sodium sulfide? cuso4 + na2s → cus + na2so4 a. this is a redox reaction because copper gained electrons. b. this is a redox reaction because sodium lost electrons. c. this is a redox reaction because sulfur gained electrons. d. this is not a redox reaction because no electrons were transferred. e. this is not a redox reaction because oxygen did not gain electrons.

D - This is not a redox reaction because no electrons were transferred.

In Redox reactions, typically subscripts are replaced with a coefficient. In the equation given, each reactant and product maintains the same subscripts that they began with and did not gain a coefficient, thus, not being a redox reduction.

Hope this helps!

option D

Explanation: In redox reaction both oxidation and reduction Occurs at a time in single reaction.

And oxidation numbers will change.

But here there was no change in oxidation no of both Cu and Na.

They are remains same before and after the reaction.

Hence it is not a redox reaction.

c is the answer because when something is left after something evaporates that shows the chemical change.