Answer to Question #311461 in General Chemistry for Ndiza

Question

on complete combustion 0.246g of an organic compound gave 0.198g of CO2 and 0.1014g of H2O. What is the ratio of carbon and hydrogen atoms in the compound?

Answer 1

Solution:

The molar mass of CO₂ is 44.01 g/mol

Therefore,

Moles of CO₂ = (0.198 g CO₂) × (1 mol CO₂ / 44.01 g CO₂) = 0.00450 mol CO₂

The molar mass of H₂O is 18.0153 g/mol

Therefore,

Moles of H₂O = (0.1014 g H₂O) × (1 mol H₂O / 18.0153 g H₂O) = 0.00563 mol H₂O

Schematic equation:

CO₂ → C

According to the shematic equation above:

Moles of C = Moles of CO₂ = 0.00450 mol

Moles of C = 0.00450 mol

Schematic equation:

H₂O → 2H

According to the shematic equation above

Moles of H = 2 × Moles of H₂O

Moles of H = 2 × 0.00563 mol = 0.01126 mol

Moles of H = 0.01126 mol

Thus, the ratio of carbon and hydrogen atoms in the compound is:

Moles of C : Moles of H = 0.00450 mol : 0.01126 mol = 1 : 2.5

Moles of C : Moles of H = 1 : 2.5

Answer: The ratio between the carbon and hydrogen atoms is 1 : 2.5