Analysis of a hydrocarbon shows that it contains 0.93g of Carbon per gram of the compound. The mole ratio of…

Analyze the question: A hydrocarbon contains only C and H. Per 1 g of compound, there is 0.93 g of carbon, so the rest is hydrogen. We need the mole ratio C : H.

Concept: Mole = mass ÷ molar mass. Divide each mole value by the smallest one to get the simplest ratio.

Solution:

1. Mass of C = 0.93 g
2. Mass of H = 1 − 0.93 = 0.07 g

3. Moles of C = 0.93 ÷ 12 = 0.0775
4. Moles of H = 0.07 ÷ 1 = 0.07

5. Ratio C : H = 0.0775 : 0.07

Divide both by the smaller value (0.07):

• C = 0.0775 ÷ 0.07 ≈ 1.1
• H = 0.07 ÷ 0.07 = 1

So the ratio is approximately 1 : 1 (the small difference comes from rounding 0.93 in the question; the compound is like benzene or ethyne, empirical formula CH).

Checking the other options: 1:2 would need about 85.7% carbon (like alkenes), 2:1 and 2:3 would give very different percentages, so none of them fits 93% carbon. For CH, the carbon percentage is 12/13 = 92.3%, which matches 0.93 g.

Answer: A. 1:1

Tip: For hydrocarbons, always get hydrogen by subtraction (1 − mass of C). Also remember that about 92% carbon means empirical formula CH (benzene, ethyne), while about 85.7% carbon means CH₂ (alkenes).