Answer to Question #285223 in Chemistry for michelle

Question

For the following redox reaction: MnO₄⁻ (aq) + Ni (s) → MnO₂ (s) + Ni²⁺ (aq). Show how you would balance the reaction if it were in an acidic solution. 

Answer 1

Question:

for the following redox reaction: MnO₄⁻ (aq) + Ni (s) → MnO₂ (s) + Ni²⁺ (aq). Show how you would balance the reaction if it were in an acidic solution. 

Answer:

For the reaction MnO₄⁻ (aq) + Ni (s) → MnO₂ (s) + Ni²⁺ (aq), one should write the half reactions first. In acidic solution, in order to remove oxygen atoms, one should add protons and get water:

MnO₄⁻ (aq) + 4H⁺ +3e^- $\rightarrow$ MnO₂ (s) + 2H₂O

Ni(s) - 2e^- $\rightarrow$ Ni²⁺(aq)

In order to equilibrate the number of the electrons in the half reactions, one should multiply the first equation by a factor of 2 and the second one by a factor of 3. Adding up the two half reactions we get:

2MnO₄⁻ (aq) + 8H⁺ +6e^- +3Ni(s) - 6e^-$\rightarrow$ 2MnO₂ (s) + 4H₂O+ 3Ni²⁺(aq)

Simplifying the expression, we get the balanced reaction equation:

2MnO₄⁻ (aq) + 8H⁺ +3Ni(s) $\rightarrow$ 2MnO₂ (s) + 4H₂O+ 3Ni²⁺(aq).