| Special Properties of Transition Elements |
| Transition Elements have more than One Oxidation Numbers |
- Oxidation number of transition elements is as below:
|
Transition Elements
|
Oxidation Number
|
Compound
|
| Chromium, Cr |
+3 |
Chromium(III) chloride, \(CrCl_3\)
|
| +6 |
Potassium dichromate(VI), \(K_2Cr_2O_7\)
|
| Manganese, Mn |
+2 |
Manganese(II) chloride, \(MnCl_2\)
|
| +4 |
Manganese(IV) oxide, \(MnO_2\)
|
| +7 |
Potassium manganate(VII), \(KMnO_4\)
|
| Iron, Fe |
+2 |
Iron(II) sulphate, \(FeSO_4\)
|
| +3 |
Iron(III) chloride, \(FeCl_3\)
|
| Copper, Cu |
+1 |
Copper(I) oxide, \(Cu_2O\)
|
| +2 |
Copper(II) oxide, \(CuO\)
|
| Nickel, Ni |
+2 |
Nickel(II) sulphate, \(NiSO_4\)
|
| +3 |
Nickel(III) chloride, \(NiCl_3\)
|
|
| Transition Elements form Coloured Compounds |
| Transition Elements |
Ion
|
Colour of Solution
|
| Chromium, Cr |
Chromium(III) ion, \(Cr^{3+}\) |
Green |
| Dichromate(VI) ion, \(Cr_2O_7^{2-}\) |
Orange |
| Manganese, Mn |
Manganese(II) ion, \(Mn^{2+}\) |
Pink |
| Manganate(VII) ion, \(MnO_4\,^-\) |
Purple |
| Iron, Fe |
Iron(II) ion,, \(Fe^{2+}\) |
Green |
| Iron(III) ion, \(Fe^{3+}\) |
Brown |
| Copper, Cu |
Copper(II) ion, \(Cu^{2+}\) |
Blue |
| Nickel, Ni |
Nickel(II) ion, \(Ni^{2+}\) |
Green |
|
| Transition Elements Function as a Catalyst to Increase the Rate of Reaction |
- The use of iron as the catalyst in the Haber process to produce ammonia.
- \(\,\\N_2 + 3H_2 \xrightarrow[]{Fe} 2NH_3\)
|
|
| Uses of Transition Elements in the Industry |
| Element or Compound |
Uses |
| Iron, Fe |
- Used as a catalyst in the Haber Process to produce ammonia, 𝑁𝐻3NH3
- Used to build bridges
|
| Platinum, Pt |
Used as a catalyst in the Ostwald Process to produce nitric acid, \(HNO_3\) |
| Vanadium(V) oxide, \(V_2O_5\) |
Used as a catalyst in the Contact Process to produce sulphuric acid, \(H_2SO_4\) |
| Nickel, Ni or Platinum, Pt |
Used as a catalyst in the hydrogenation process on vegetable oils to produce margarine |
| Manganese, Mn |
Used to make stained glass windows |
| Titanium, Ti |
Used to make paints |
|
