Question

Which of the following describes an element that is oxidized in a reaction

A It gains electrons during a reaction
B It has a decrease in it oxidation number
C Al yields Al3+ + 3e-
D F2 + 2e- yields 2 F-

Answer 1

The correct options is:

C Al → Al³⁺ + 3e⁻

Step-by-step explanation:

Oxidation-reduction reactions or redox reactions are those in which an electron transfer occurs between the reagents. An electron transfer implies that there is a change in the number of oxidation between the reagents and the products.

The gain of electrons is called reduction and the loss of electrons oxidation. That is to say, there is oxidation whenever an atom or group of atoms loses electrons (or increases its positive charges) and in the reduction an atom or group of atoms gains electrons, increasing its negative charges or decreasing the positive ones.

As mentioned, oxidation occurs whenever an atom or group of atoms loses electrons (or increases their positive charges). This is expressed, for example, by:

A → Aⁿ⁺ + ne⁻

where "n" is the amount of electrons lost or positive charge gained by the element.

On the other hand, as mentioned, there is a reduction whenever an atom or group of atoms gains electrons, increasing its negative charges or decreasing the positive ones. This is expressed by:

Aⁿ⁺ + ne⁻ → A

where en is the amount of electrons gained.

So, the correct options is:

C Al → Al³⁺ + 3e⁻

Answer 2

Answer: C. Al yields
`Al^(3+)+ 3e^-`

Step-by-step explanation: Oxidation is a process in which loss of electrons take place and thus results in increase in oxidation number of the element.

`A\rightarrow A^(n+)+ne^-`

Reduction is a process in which gain of electrons take place and thus results in decrease in oxidation number of the element.

`A^(n+)+ne^-\rightarrow A`