5Fe2 2Mn2 8H2O2MnO4- 5Fe 16H In the above reaction, the oxidation state of iron changes from to . How many electrons are transferred in the reaction?

The oxidation number of iron changes from 2+ to 0.

10 electrons are transferred in the reaction.

Explanation:

Step 1: Write the balanced redox reaction

5 Fe²⁺ + 2 Mn²⁺ + 8 H₂O ⇒ 2 MnO₄⁻ + 5 Fe + 16 H⁺

Step 2: identify both half-reactions

Reduction: 5 Fe²⁺ + 10 e⁻ ⇒ 5 Fe

Oxidation: 2 Mn²⁺ + 8 H₂O ⇒ 2 MnO₄⁻ + 16 H⁺ + 10 e⁻

Step 3: Identify the oxidation state change of iron

Iron changes from Fe²⁺ to Fe, that is, the oxidation number changes from 2+ to 0.

Step 4: Determine how many electrons are transferred in the reaction?

According to both balanced half-reactions, 10 electrons are transferred in the reaction.

the answer is definitely c.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.