Solve this equation by oxidation-reduction method, balance this equation basically. Cu plus HNO3 goes to Cu dinitrate, Cu bracket NO3 bracket closed twice, plus NO2 plus H2O. And then, solve the equation, balance the equation by half-cell reaction. The equation is Au plus 3I plus H2 gas goes to H plus I plus Au atom. And the other question for ion-electron balance, half-cell equation for balance is NO3 minus goes to NO, and the other half reaction is Br minus 1 ion goes to Br2, bromine gas.
| Step | Detail |
|---|---|
| Cu: 0 → +2 | Loses 2e⁻ (oxidized) |
| N: +5 → +4 | Gains 1e⁻ (reduced) |
| Equalize | 1 Cu : 2 N → ratio 1:2 |
| Half-Reaction | × factor |
|---|---|
| Au³⁺ + 3e⁻ → Au | × 2 |
| H₂ → 2H⁺ + 2e⁻ | × 3 |
Give a final equation written of all three, and there is no I minus or I type of thing in the AU wale equation. There is just AU plus 3 as H2 goes to H plus plus AU. That's it.
You have to add the equation of NO3 and Br minus 1. It will form one equation, the half-cell equation. So you have to complete one equation from these two. So sum up in one equation after canceling everything.
| Left | Right | |
|---|---|---|
| N | 2 | 2 ✓ |
| O | 6 | 4 ✓ (6 from NO₃⁻ = 2 in NO + 4 in H₂O) |
| H | 8 | 8 ✓ |
| Br | 6 | 6 ✓ |
| Charge | (−2) + (+8) + (−6) = 0 | 0 + 0 + 0 = 0 ✓ |