10. Convert 250 grams of $$ \mathrm{CH}_{4} $$ to moles.

Question

UpStudy AI · Accepted Answer

To convert 250 grams of methane ($$\mathrm{CH}_{4}$$) to moles, follow these steps:

### 1. Determine the Molar Mass of $$\mathrm{CH}_{4}$$

First, calculate the molar mass by adding the atomic masses of carbon and hydrogen:

- **Carbon (C):** $$12.01 \, \text{g/mol}$$
- **Hydrogen (H):** $$1.008 \, \text{g/mol}$$ (there are 4 hydrogen atoms in $$\mathrm{CH}_{4}$$)

$$
\text{Molar mass of } \mathrm{CH}_{4} = 12.01 \, \text{g/mol} + (4 \times 1.008 \, \text{g/mol}) = 12.01 + 4.032 = 16.042 \, \text{g/mol}
$$

### 2. Use the Formula to Convert Grams to Moles

The number of moles ($$n$$) can be calculated using the formula:

$$
n = \frac{\text{Mass}}{\text{Molar Mass}}
$$

Plugging in the values:

$$
n = \frac{250 \, \text{g}}{16.042 \, \text{g/mol}} \approx 15.57 \, \text{mol}
$$

### 3. Round to Appropriate Significant Figures

Assuming the mass (250 g) is given to three significant figures, the number of moles should also be reported to three significant figures:

$$
n \approx 15.6 \, \text{mol}
$$

### **Final Answer:**

250 g of CH₄ is equal to approximately 15.6 moles.
250 grams of CH₄ is approximately 15.6 moles.

10. Convert 250 grams of \( \mathrm{CH}_{4} \) to moles.