51.9k views
0 votes
A 0.250 g sample of hydrocarbon undergoes complete combustion to produce 0.845 g of CO₂ and 0.173 g of H₂O. What is the empirical formula of this compound?

User Krfurlong
by
8.4k points

1 Answer

2 votes

Final answer:

To find the empirical formula of the hydrocarbon from the combustion products, calculate the moles of carbon from CO₂ and the moles of hydrogen from H₂O. This combustion analysis leads to a 1:1 mole ratio of carbon to hydrogen, which means the empirical formula is CH.

Step-by-step explanation:

To determine the empirical formula of the hydrocarbon, we first need to calculate the moles of carbon and hydrogen in the sample. We start by using the masses of CO₂ and H₂O to find the number of moles of each element.

Calculation of Carbon:

From the mass of CO₂, we can calculate the moles of CO₂ and, subsequently, the moles of carbon:

0.845 g CO₂ × (1 mol CO₂ / 44.01 g CO₂) = 0.0192 mol CO₂

0.0192 mol CO₂ × (1 mol C / 1 mol CO₂) = 0.0192 mol C

Calculation of Hydrogen:

From the mass of H₂O, we calculate the moles of H₂O and, subsequently, the moles of hydrogen atoms:

0.173 g H₂O × (1 mol H₂O / 18.02 g H₂O) = 0.0096 mol H₂O

0.0096 mol H₂O × (2 mol H / 1 mol H₂O) = 0.0192 mol H

Determining the Empirical Formula:

With 0.0192 moles of carbon and 0.0192 moles of hydrogen, we have a 1:1 ratio, giving us the empirical formula of CH.

User Dan Hennion
by
8.1k points