Question

How many grams of carbon are found in 88 grams of propane, C3H8?
Group of answer choices

36 g

6 g

3 g

72 g

Answer 1

To determine how many grams of carbon are found in 88 grams of propane (C₃H₈), we can follow these steps:

1. **Calculate the molar mass of propane (C₃H₈)**:
- Carbon (C) has a molar mass of about 12.01 g/mol.
- Hydrogen (H) has a molar mass of about 1.008 g/mol.

Molar mass of C₃H₈:
\[
(3 \times 12.01 \, \text{g/mol}) + (8 \times 1.008 \, \text{g/mol}) = 36.03 \, \text{g/mol} + 8.064 \, \text{g/mol} = 44.094 \, \text{g/mol}
\]

2. **Find the fraction of the mass that is carbon**:
- Total mass of carbon in one mole of propane:
\[
3 \times 12.01 \, \text{g} = 36.03 \, \text{g}
\]
- Therefore, the fraction of the mass that is carbon in propane is:
\[
\frac{36.03 \, \text{g}}{44.094 \, \text{g}} \approx 0.816
\]

3. **Calculate the mass of carbon in 88 grams of propane**:
\[
\text{Mass of carbon} = 0.816 \times 88 \, \text{g} \approx 71.9 \, \text{g}
\]

Rounding this value gives approximately **72 grams** of carbon.

Therefore, the answer is **72 g**.