We will assume that the reaction is under acidic condition unless stated otherwise. When balancing redox reactions under acidic conditions, we will follow the following steps.
Step 1: Separate the whole reaction into two half-reactions
Step 2: Balance the non-hydrogen and non-oxygen elements first
Step 3: Balance oxygen by adding H2O to the side that needs oxygen (1 O: 1 H2O)
Step 4: Balance hydrogen by adding H+ to the side that needs hydrogen (1 H: 1 H+)
Step 5: Balance the charges: add electrons to the more positive side (or less negative side)
Step 6. Balance electrons on the two half-reactions
Step 7. Get the overall reaction by adding the two reactions
When balancing under basic conditions, additional steps are required:
Step 8. Balance the remaining H+ by adding an equal amount of OH- ions to both sides
Step 9. H+(aq) will combine with OH-(aq) to form H2O(l)
Step 10. Cancel out common species
Balance the redox reaction under acidic conditions:
HNO3 + H2S → NO + S + H2O
*Before balancing the redox reaction:
• ignore H+, OH-, and H2O in the starting reaction
Balance the following redox reaction by inserting the appropriate coefficients.
HNO3 + H2S → NO +S + H2O
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Balancing Redox Reactions concept. You can view video lessons to learn Balancing Redox Reactions. Or if you need more Balancing Redox Reactions practice, you can also practice Balancing Redox Reactions practice problems.