A gaseous hydrogen and carbon containing compound is decomposed and found to contain 82.66% carbon and 17.34% hydrogen by mass. The mass of 158 mL of the gas, measured at 556 mmHg and 25 ∘C, was found to be 0.275 g. What is the molecular formula of the compound?

Question

Chemistry

Kendall Stokes

26 October, 08:19

A gaseous hydrogen and carbon containing compound is decomposed and found to contain 82.66% carbon and 17.34% hydrogen by mass. The mass of 158 mL of the gas, measured at 556 mmHg and 25 ∘C, was found to be 0.275 g. What is the molecular formula of the compound?

+5

Answers (1)

Know the Answer?

Louis Whitehead · Answer 1

For the answer to the question above, I'll show the solution to my answers

moles C = 82.66 g / 12.0111 g/mol=6.882

moles H = 17.34 g / 1.008 g/mol=17.20

17.20 / 6.882 = 2.5 = > H

6.882 / 6.882 = 1 = > C

to get whole numbers multiply by 2

C2H5 (empirical formula Molar mass = 29.062 g/mol)

n = pV/RT = 0.732 x 0.158 L / 0.08206 x 298 K = 0.00473

molar mass = 0.275 / 0.00473 = 58.1 g/mol

58.1 / 29.062 = 2

multiply by two the empirical formula

C4H10