When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 20.4 g of carbon were burned in the presence of 71.1 g of oxygen, 16.7 g of oxygen remained unreacted. What mass of carbon dioxide was produced?
Express your answer to three significant figures and include the appropriate units.
C + O2 ---> CO2
Mols of C
20.4 /12 g/mol = 1.7 mol of C
result is 1.7 mol of CO2
C = 12
O2 = 32
CO2 = 44 g/mol
1.7 mol * 44 g/mol = 74.8 grams
How much heat is evolved if 2 moles of C3H8 is burned?
To find the mass of carbon dioxide produced, we need to consider the conservation of mass. The total mass of carbon and oxygen initially present should be equal to the total mass of carbon dioxide and any unreacted oxygen.
First, calculate the mass of oxygen that reacted with carbon: 71.1 g - 16.7 g = 54.4 g.
Since carbon reacts with oxygen in a 1:1 ratio to form carbon dioxide, the mass of carbon dioxide produced will be equal to the mass of carbon burned. Therefore, the mass of carbon dioxide produced is 20.4 g.
Thus, the mass of carbon dioxide produced is 20.4 g (to three significant figures).