Question

What is the percent composition of carbon in heptane c7h16

Answer 1

Answer: the percent composition of carbon in heptane is 83.9%

Explanation:

1) Atomic masses of the atoms:

• C: 12.01 g/mol

• H: 1.008 g/mol

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