Which statement is incorrect among the following ?

Options

A. Calamine and siderite are carbonates
B. Argentite and cuprite are oxides
C. Zinc blende and pyrites are sulphides
D. Malachite and azurite are ores of copper

Answer

To determine which statement is incorrect among the provided options, we will analyze each statement one by one.

### Step 1: Analyze the first statement
**Statement:** Calamine and siderite are carbonates.
- **Calamine** is zinc carbonate, with the formula **ZnCO3**.
- **Siderite** is iron(II) carbonate, with the formula **FeCO3**.
- Both compounds contain the carbonate ion (CO3) and are indeed carbonates.
**Conclusion:** This statement is correct.

### Step 2: Analyze the second statement
**Statement:** Argentite and cuprite are oxides.
- **Argentite** has the formula **Ag2S**, which indicates it is a sulfide, not an oxide.
- **Cuprite** has the formula **Cu2O**, which is indeed an oxide.
- Since argentite is a sulfide, this statement is incorrect.
**Conclusion:** This statement is incorrect.

### Step 3: Analyze the third statement
**Statement:** Zinc blend and pyrite belong to the sulfide group.
- **Zinc blend** (also known as sphalerite) has the formula **ZnS**, which is a sulfide.
- **Pyrite** has the formula **FeS2**, which is also a sulfide.
- Both compounds are sulfides.
**Conclusion:** This statement is correct.

### Step 4: Analyze the fourth statement
**Statement:** Malachite and azurite are ores of copper.
- **Malachite** has the formula **CuCO3·Cu(OH)2**, which is a copper carbonate.
- **Azurite** has the formula **Cu3(CO3)2(OH)2**, which is also a copper carbonate.
- Both are known ores of copper.
**Conclusion:** This statement is correct.

### Final Conclusion
After analyzing all the statements, we find that the second statement regarding argentite and cuprite is incorrect. Therefore, the answer to the question is:

**Incorrect Statement:** Argentite and cuprite are oxides.

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