10 g of dolomite contains

Options

A. 0.1 mole of `CaCO_(3)`
B. 0.108 g atom of C
C. `6 xx 10^(23)` atoms of Ca
D. 1 g equivalent of Ca

Explanation

To solve the problem regarding the composition of 10 g of dolomite, we will follow these steps:

### Step 1: Identify the Formula of Dolomite
Dolomite is a mineral composed of calcium magnesium carbonate. Its chemical formula is:
\[ \text{CaMg(CO}_3\text{)}_2 \]

### Step 2: Calculate the Molar Mass of Dolomite
To find the molar mass of dolomite, we need to sum the atomic masses of its constituent elements:
- Calcium (Ca): 40 g/mol
- Magnesium (Mg): 24 g/mol
- Carbon (C): 12 g/mol (2 atoms in the formula)
- Oxygen (O): 16 g/mol (6 atoms in the formula)

Calculating the molar mass:
\[ \text{Molar mass of Dolomite} = 40 + 24 + (2 \times 12) + (6 \times 16) = 40 + 24 + 24 + 96 = 184 \text{ g/mol} \]

### Step 3: Calculate the Number of Moles of Dolomite
Using the formula for moles:
\[ \text{Moles of Dolomite} = \frac{\text{Given mass}}{\text{Molar mass}} = \frac{10 \text{ g}}{184 \text{ g/mol}} \approx 0.0543 \text{ moles} \]

### Step 4: Determine the Number of Carbon Atoms
In dolomite, there are 2 moles of carbon for every mole of dolomite. Therefore, the number of moles of carbon in 0.0543 moles of dolomite is:
\[ \text{Moles of Carbon} = 0.0543 \text{ moles of dolomite} \times 2 = 0.1086 \text{ moles of carbon} \]

### Step 5: Convert Moles of Carbon to Gram Atoms
Since 1 mole of any element contains \(6.022 \times 10^{23}\) atoms (Avogadro's number), the number of carbon atoms is:
\[ \text{Number of Carbon Atoms} = 0.1086 \text{ moles} \times 6.022 \times 10^{23} \text{ atoms/mole} \approx 6.53 \times 10^{22} \text{ atoms} \]

### Step 6: Evaluate the Options
Now, we need to evaluate the provided options:
- **Option A:** 0.1 mole of CaCO3 (Incorrect, as dolomite does not contain CaCO3)
- **Option B:** 0.1 and 8 gram atom of C (Correct, as we calculated approximately 0.1086 moles of carbon)
- **Option C:** 16 × 10^23 atoms of calcium (Incorrect, as we have fewer moles of calcium)
- **Option D:** 1 gram equivalent of calcium (Incorrect, as we calculated the equivalent weight differently)

### Conclusion
The correct answer is **Option B**.

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