When carbon is burned in air, it reacts with oxygen to form carbon dioxide. when 24.0 g of carbon were burned in the presence of 82.7 g of oxygen, 18.7 g of oxygen remained unreacted. what mass of carbon dioxide was produced?

mass of CO2 = 88 g

Explanation:

It is stated in question that 18.7 g of oxygen remained unreacted which means that carbon is limiting reactant. Thus the amount of carbon dioxide produced depend upon the amount of carbon.

Given data:

mass of carbon = 24 g

total mass of oxygen 82.7 g

mass of unreacted oxygen = 18.7 g

mass of carbon dioxide = ?

Solution:

First of we will calculate the moles of carbon.

number of moles of carbon = mass of carbon / atomic weight

number of moles of carbon = 24 g/ 12 g/mol = 2 mol

Chemical equation:

C + O2 → CO2

now we compare the number of moles of carbon and carbon dioxide,

  C   :  CO2

  1    :    1

 2    :    2

Now we will calculate the mass of carbon dioxide from moles.

number of moles of CO2 = mass of CO2 / molar mass of CO2

2 mol × 44 g/mol = mass

mass of CO2 = 88 g