Question

Given the redox reaction:

Cr3+ + Al-->Cr + Al3+
As the reaction takes place, there is a transfer of
(1) electrons from Al to Cr3+
(2) electrons from Cr3+ to Al
(3) protons from Al to Cr3+
(4) protons from Cr3+ to Al

Answer 1

In this reaction, Al lose electrons and change to Al3+. Cr3+ gain electrons and change to Cr. So the electrons transfer from Al to Cr3+. Protons will not transfer in a chemical reaction. So the answer is (1).

Answer 2

Answer: (1) electrons from Al to
`Cr^(3+)`

Explanation: Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.

Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.

For the given reaction:

`Cr^(3+)+Al\rightarrow Cr+Al^(3+)`

The oxidation state of chromium reduces from +3 to 0, it is getting reduced and gains electrons. The oxidation state of aluminium increases from 0 to +3. Thus, it is getting oxidized and it loses electrons. Thus electrons are transferred from
`Al` to
`Cr^(3+)`