Question

A sample of a hydrocarbon is found to contain 7.48g carbon and 2.52g hydrogen. What is the empirical

formula for this compound?

Answer 1

CH₄

Step-by-step explanation:

To determine the empirical formula of the hydrocarbon, we need to follow a series of steps.

Step 1: Determine the mass of the compound

The mass of the compound is equal to the sum of the masses of the elements that form it.

m(CxHy) = mC + mH = 7.48 g + 2.52 g = 10.00 g

Step 2: Calculate the percent by mass of each element

%C = mC / mCxHy × 100% = 7.48 g / 10.00 g × 100% = 74.8%

%H = mH / mCxHy × 100% = 2.52 g / 10.00 g × 100% = 25.2%

Step 3: Divide each percentage by the atomic mass of the element

C: 74.8/12.01 = 6.23

H: 25.2/1.01 = 24.95

Step 4: Divide both numbers by the smallest one, i.e. 6.23

C: 6.23/6.23 = 1

H: 24.95/6.23 ≈ 4

The empirical formula of the hydrocarbon is CH₄.