| 1. | \(\mathrm{Na}_2\mathrm{[Fe(C N)_5 \mathrm{NO}]}\) | 2. | \(K_2[\mathrm{Fe}(\mathrm{CN})_5 Cl]\) |
| 3. | \(\mathrm{Na}_2\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O})_5 \mathrm{NO}\right]\right.\) | 4. | \(\mathrm{Na}_2[\mathrm{Mn}\mathrm{(CN)_5 \mathrm{Br}}]\) |
| 1. | Nitrogen | 2. | Oxygen |
| 3. | Carbon dioxide | 4. | Hydrogen |
| 1. | \(H_2\) | 2. | \(SO_2\) |
| 3. | \(H_2S\) | 4. | \(CO_2\) |
| 1. | \(SO^{2-}_4\) | 2. | \(S^{2-}\) |
| 3. | \(Cl^-\) | 4. | \(H^+\) |
| 1. | It turns white | 2. | It remains unchanged |
| 3. | It turns black | 4. | It turns yellow |
| 1. | SO42- | 2. | OH- |
| 3. | \(SO_3^{-2}\) | 4. | None of the above |
| 1. | Red to green | 2. | Green to red |
| 3. | Orange to green | 4. | Yellow to green |