Question

An unknown compound contains only carbon, hydrogen, and oxygen (C,H,O:) Combustion of 4.00 g of this compound produced 5.87 g of carbon dioxide and 2.40 g of water.

Part A How many moles of carbon C were in the original sample? Express your answer to three significant figures and include the appropriate units. View Available Hint(s) 0.133 mol Previous Answers Correct Since there is one mole of carbon for every mole of carbon dioxide, the number of moles of each are equivalent

Answer 1

The original sample contained 0.133 moles of carbon, calculated by dividing the mass of the produced CO2 (5.87 g) by the molar mass of CO2 (44.01 g/mol).

Step-by-step explanation:

To determine the number of moles of carbon present in a compound from its combustion products, we should look at the mass of carbon dioxide produced. Since each molecule of CO₂ comes from one atom of carbon, we can use the molar mass of carbon in CO₂ to find out how much carbon was in the original sample. The molar mass of CO₂ is 44.01 g/mol, and given that 5.87 g of CO₂ were produced, we calculate the moles of carbon as follows:

1. Calculate the moles of CO₂ by dividing the mass of CO₂ by its molar mass: Moles of CO₂ = 5.87 g CO₂ ÷ 44.01 g/mol = 0.133 mol.
2. Assume one mole of CO₂ corresponds to one mole of carbon: Moles of C = 0.133 mol of CO₂.

The original sample thus contained 0.133 mol of carbon.