Question

When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 26.4 g of carbon were burned in the presence of 82.1 g of oxygen, 11.7 g of oxygen remained unreacted. What mass of carbon dioxide was produced?
Express your answer to one decimal place and include the appropriate units.

Answer 1

When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 27.6 g of carbon...?

Answer 2

C(s) + O2(g) --> CO2(g)
27.6g .... 88.0g ................. initial amounts
0g .........14.4g ................. amounts when reaction complete

That means that C was the limiting reactant, and the amount of CO2 is based on the amount of carbon that burned. Covert 27.6 grams of carbon to moles. The moles of CO2 will be the same, since they are in a 1:1 mole ratio. Then convert the moles of CO2 to grams.

27.6g C x (1 mol C / 12.0 g C) x (1 mol CO2 / 1 mol C) x (44.0g CO2 / 1 mol CO2) = 101.2 g CO2 or 101 grams of carbon to three significant digits.