How many electrons are transferred in the following reaction?

(the reaction is unbalanced.)

mg(s) + al3+(aq) → al(s) + mg2+(aq)

3Mg +2Al^3 ⇆ 3 Mg^2+ + 2Al

In this reaction 6 electrons are transferred

Explanation:

Step 1: The half reactions

Mg  -2e- ⇆ Mg^2+

Al^3+ +3e- ⇆ Al

Step 2: Balance both equations

3*(Mg  -2e- ⇆ Mg^2+)

2(Al^3+ +3e- ⇆ Al)

3Mg  -6e- ⇆ 3Mg^2+

2Al^3+ +6e- ⇆ 2Al

Step 3: The netto reaction

3Mg +2Al^3 ⇆ 3 Mg^2+ + 2Al

In this reaction 6 electrons are transferred

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.