How do you balance redox reactions in basic solution?

WARNING — this is a long answer.
In basic solution, you balance redox equations as if they were in acid. At the end, you use OH⁻ to convert to base.


Balance the following equation in basic solution:
MnO₄⁻ + CN⁻ → MnO₂ + CNO⁻


Step 1: Separate the equation into two half-reactions.
MnO₄⁻ → MnO₂
CN⁻ → CNO⁻

Step 2: Balance all atoms other than H and O.

Step 3: Balance O by adding H₂O to the deficient side.
MnO₄⁻ → MnO₂+ 2H₂O
CN⁻+ H₂O → CNO⁻

Step 4: Balance H by adding H⁺ to the deficient side.
MnO₄⁻+ 4H⁺ → MnO₂+ 2H₂O
CN⁻+ H₂O → CNO⁻ + 2H⁺

Step 5: Balance charge by adding electrons to the more positive side.
MnO₄⁻+ 4H⁺ + 3e⁻ → MnO₂+ 2H₂O
CN⁻+ H₂O → CNO⁻ + 2H⁺ + 2e⁻

Step 6: Multiply each half-reaction by a factor that gives the lowest common multiple of the electrons transferred.
In this case, the lowest common multiple of 3 and 2 is 6.
We multiply the first half-reaction by 2 and the second half-reaction by 3.

2 × [MnO₄⁻+ 4H⁺ + 3e⁻ → MnO₂+ 2H₂O]
3 × [CN⁻+ H₂O → CNO⁻ + 2H⁺ + 2e⁻]

Step 7: Add the two half-reactions, cancelling any like terms.

2MnO₄⁻+ 3CN⁻+ 2H⁺ → 2MnO₂ + 3CNO⁻ + H₂O

This is the balanced equation in acid solution. We must now convert to base solution.

Step 8: Add enough multiples of the equations H⁺ + OH⁻ → H₂O or
H₂O → H⁺ + OH⁻ to cancel the H⁺ in the redox equation, cancelling like terms.

2MnO₄⁻+ 3CN⁻+ 2H⁺ → 2MnO₂ + 3CNO⁻ + H₂O
2H₂O → 2H⁺ + 2OH⁻

2MnO₄⁻+ 3CN⁻+ H₂O → 2MnO₂ + 3CNO⁻ + 2OH⁻

Step 9: Check that atoms balance.
On the left: 2 Mn; 9 O; 3 C; 3 N; 2 H
On the right: 2 Mn; 9 O; 3 C; 3 N; 2 H

Step 10: Check that charges balance.
On the left: 2- + 3- = 5-
On the right: 3- + 2- = 5-

The balanced equation is
2MnO₄⁻+ 3CN⁻+ H₂O → 2MnO₂ + 3CNO⁻ + 2OH⁻

Show more

Calculate Your Essay Price
(550 words)

Approximate price: $22

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
The price is based on these factors:
Academic level
Number of pages
Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more

Order your essay today and save 10% with the coupon code: best10