Question

A 3.00 g sample of a gaseous compound was found to contain 2.560g of carbon and 0.440g of hydrogen. What is the simplest formula for the compound?

a. CH₂
b. C₂H₅
c. C₃H₇
d. C₄H₁₀

Answer 1

By calculating the moles of carbon and hydrogen and the simplest whole number ratio, the empirical formula of the gaseous compound is determined to be CH₂.

Step-by-step explanation:

Solving for the Simplest Formula

To find the simplest formula of the compound, we first need to calculate the moles of carbon and hydrogen in the sample. Given the masses of carbon (2.560 g) and hydrogen (0.440 g), we use the molar mass of carbon (12.01 g/mol) and hydrogen (1.01 g/mol) to find:

• Moles of C = 2.560 g / 12.01 g/mol = 0.213 mol
• Moles of H = 0.440 g / 1.01 g/mol = 0.436 mol

The next step is to divide each by the smallest number of moles to determine the simplest whole number ratio:

• Ratio of C to H = 0.213 mol / 0.213 mol = 1
• Ratio of H to C = 0.436 mol / 0.213 mol ≈ 2

The empirical formula is therefore CH2, which corresponds to option a. CH2.