Which among the following statements are correct ?

Options

A. Aquadig and oildig are made up of graphite
B. Graphite reacts with conc `HNO_3` acid to form mellitic acid ` C_6 (COOH)_6`
C. both `CO` and `C_3 O_2` are toxic
D. Zircon `(ZrSiO_4)` is a gemstone .

Answer

To determine which statements are correct, let's analyze each statement step by step:

### Step 1: Analyze the First Statement
**Statement:** Aqua dag and oil dag are made up of graphite.

- **Explanation:** Aqua dag is a colloidal dispersion of graphite in distilled water. Oil dag, similarly, consists of graphite but is dispersed in oil. Both are indeed made from graphite.
- **Conclusion:** This statement is **true**.

### Step 2: Analyze the Second Statement
**Statement:** Graphite reacts with concentrated HNO3 acid and forms malic acid (C6(COOH)6).

- **Explanation:** When graphite reacts with concentrated nitric acid (HNO3), it can form various oxidized products, including carboxylic acids. However, the specific compound mentioned, malic acid, is actually a 2-hydroxybutanedioic acid and not derived from benzene. The correct compound formed from graphite oxidation is usually referred to as a hexacarboxylic acid (like benzene-1,2,3,4,5,6-hexacarboxylic acid), not malic acid.
- **Conclusion:** This statement is **false**.

### Step 3: Analyze the Third Statement
**Statement:** Both carbon monoxide and C3O2 are toxic.

- **Explanation:** Carbon monoxide (CO) is indeed toxic as it binds with hemoglobin in the blood, preventing oxygen transport. However, C3O2 (tricarbon dioxide) is not a well-known compound and does not have established toxicity like carbon monoxide. In fact, C3O2 is not commonly recognized as a toxic substance.
- **Conclusion:** This statement is **false**.

### Step 4: Analyze the Fourth Statement
**Statement:** Zircon (ZrSiO4) is a gemstone.

- **Explanation:** Zircon is indeed a mineral with the chemical formula ZrSiO4, and it is widely recognized as a gemstone. It has been used for decorative purposes for thousands of years.
- **Conclusion:** This statement is **true**.

### Final Conclusion
The correct statements are:
- Statement 1: True
- Statement 2: False
- Statement 3: False
- Statement 4: True

Thus, the correct options are **A and D**.

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