Answer: the percent composition of carbon in heptane is 83.9%
Explanation:
1) Atomic masses of the atoms:
2) Molar mass of heptane:
- C₇H₁₆: 7 × 12.01 g/mol + 16×1.008 g/mol = 100.2 g/mol
3) Mass of carbon in one mole of heptane:
- C₇: 7 × 12.01 g/mol = 84.07 g/mol
3) Percent composition of carbon:
- % = (mass in grams of C) / (mass in grams of C₇H₁₆) × 100 =
= (84.07 g/ 100.2 g) × 100 = 83.9% ← answer
