Question

What is the percentage of carbon in ethanol (\(C_{2}H_{5}OH\)) ? 
(Atomic masses: C = 12, H = 1, O = 16)

• A. 52.2%
• B. 40.0%
• C. 60.0%
• D. 46.1%

Hint:

To find the percentage of an element in a compound, divide the total mass of that element by the molar mass of the compound and multiply by 100.

Answer 1

The Correct Option is A

Step 1: Calculate the molar mass of ethanol \(C_{2}H_{5}OH\): 
\[ = 2 \times 12 + 6 \times 1 + 1 \times 16 = 24 + 6 + 16 = 46 \, \text{g/mol} \]
Step 2: Calculate the total mass of carbon in one mole of ethanol: 
\[ = 2 \times 12 = 24 \, \text{g} \]
Step 3: Calculate the percentage of carbon: 
\[ \text{Percentage of C} = \frac{24}{46} \times 100 = 52.17% \approx 52.2% \]
Step 4: Hence, the percentage of carbon in ethanol is approximately 52.2%.