Write the chemical formulae of the following ores :
(a) Haematite (b) Magnetite
(c) Limonite (d) Siderite

Answer

To answer the question regarding the chemical formulae of the ores mentioned, we will go through each ore one by one and provide their respective chemical formulae.

### Step-by-Step Solution:

1. **Hematite**:
- Hematite is an iron oxide ore.
- The chemical formula for Hematite is **Fe₂O₃**.

2. **Magnetite**:
- Magnetite is another iron oxide ore.
- The chemical formula for Magnetite is **Fe₃O₄**.

3. **Limonite**:
- Limonite is also an iron oxide, but it contains water in its structure.
- The chemical formula for Limonite is **Fe₂O₃·2H₂O** (which indicates it is hydrated).

4. **Siderite**:
- Siderite is a carbonate mineral.
- The chemical formula for Siderite is **FeCO₃**.

### Summary of Chemical Formulae:
- (a) Hematite: **Fe₂O₃**
- (b) Magnetite: **Fe₃O₄**
- (c) Limonite: **Fe₂O₃·2H₂O**
- (d) Siderite: **FeCO₃**