Question

ITS FOR AN EXAM GUYS PLEASE

Answer 1

Answer: A. $Al(s)\rightarrow Al^{3+}(aq)+3e^-$ and $Au^+(aq)+e^-\rightarrow Au(s)$

Explanation:

Galvanic cell is a device which is used for the conversion of the chemical energy produces in a redox reaction into the electrical energy.

The standard reduction potential for aluminium and gold are as follows:

$E^0_{Al^{3+}/Al}=-1.662V$

$E^0_{Au^{+}/Au}=1.83V$

Reduction takes place easily if the standard reduction potential is higher (positive) and oxidation takes place easily if the standard reduction potential is less (more negative).

Here Al undergoes oxidation by loss of electrons, thus act as anode. Gold undergoes reduction by gain of electrons and thus act as cathode.

Anode : $Al(s)\rightarrow Al^{3+}(aq)+3e^-$

Cathode : $Au^+(aq)+e^-\rightarrow Au(s)$

Thus magnesium gets oxidized.