Question

Choose the oxidation state for each reactant and product below. Mg + S ---------> Mg²⁺ +S²⁻

a. -2,
b. -1,
c. 0,
d. +1,
e. +2

Answer 1

The oxidation state of Mg and S as reactants is 0 (c). When Mg becomes Mg²⁺, it has an oxidation state of +2 (e), and when S becomes S²⁻, its oxidation state is -2 (a). Option A is the correct answer.

Step-by-step explanation:

The student is asking to determine the oxidation states for each reactant and product in the chemical reaction Mg + S → Mg²⁺ + S²⁻. In a reaction, atoms in monatomic ions are assigned an oxidation number equal to their charge. Magnesium (Mg) in its elemental form has an oxidation state of 0 because it is not combined with any other element. During the reaction, magnesium becomes a magnesium ion (Mg²⁺), which means it has lost two electrons and thereby has an oxidation state of +2. The sulfur (S) starts with an oxidation state of 0 for the same reason as magnesium and ends as a sulfide ion (S²⁻), gaining two electrons with an oxidation state of -2.

Therefore, matching the reactants and products with their corresponding oxidation states:

• Mg (reactant) has an oxidation state of 0 (c)
• S (reactant) has an oxidation state of 0 (c)
• Mg²⁺ (product) has an oxidation state of +2 (e)
• S²⁻ (product) has an oxidation state of -2 (a)

The correct options for the given reaction Mg + S → Mg²⁺ + S²⁻ are therefore: 0 (c) for Mg and S, +2 (e) for Mg²⁺, and -2 (a) for S²⁻.