An unknown compound of mass 10.7696 g containing carbon, hydrogen and oxygen was combusted in oxygen producing CO2 (29.5747 g) and H2O (12.1068 g). Caluculate the mass of oxygen produced? (Atomic masses of C-12.011 g/mol; O-15.999 g/mol; H-1.008 g/mol).
1.509 g
0.672 g
8.071 g
1.3438 g
The total mass of carbon and oxygen in the unknown compound can be calculated by subtracting the mass of hydrogen from the total mass:
10.7696 g - 12.1068 g = -1.3372 g (mass of carbon and oxygen)
This negative value indicates an error in the measurements, as the mass of the compound cannot be less than the mass of its components. Therefore, it is not possible to accurately calculate the mass of oxygen produced in the combustion reaction.
To calculate the mass of oxygen produced, we need to use the law of conservation of mass. According to this law, the total mass of reactants must be equal to the total mass of products.
Given:
Mass of CO2 = 29.5747 g
Mass of H2O = 12.1068 g
Mass of unknown compound = 10.7696 g
We can calculate the mass of carbon and hydrogen in the unknown compound as follows:
Mass of carbon = Mass of CO2 / Molar mass of CO2
= 29.5747 g / (12.011 g/mol + 2 * 15.999 g/mol)
= 29.5747 g / 44.009 g/mol
≈ 0.672 g
Mass of hydrogen = Mass of H2O / Molar mass of H2O
= 12.1068 g / (2 * 1.008 g/mol + 15.999 g/mol)
= 12.1068 g / 18.015 g/mol
≈ 0.672 g
Now, let's calculate the mass of oxygen in the unknown compound:
Mass of oxygen in the unknown compound = Mass of unknown compound - (Mass of carbon + Mass of hydrogen)
= 10.7696 g - (0.672 g + 0.672 g)
= 10.7696 g - 1.344 g
= 9.4256 g
Therefore, the mass of oxygen produced is approximately 9.4256 g.
To solve this problem, we need to use the principle of conservation of mass. According to this principle, the total mass of the reactants must be equal to the total mass of the products in a chemical reaction.
Given:
Mass of compound = 10.7696 g
Mass of CO2 produced = 29.5747 g
Mass of H2O produced = 12.1068 g
We can start by calculating the molar mass of CO2 and H2O:
CO2:
Molar mass of C = 12.011 g/mol
Molar mass of O = 15.999 g/mol
Molar mass of CO2 = (12.011 g/mol) + 2*(15.999 g/mol) = 44.009 g/mol
H2O:
Molar mass of H = 1.008 g/mol
Molar mass of O = 15.999 g/mol
Molar mass of H2O = (2*1.008 g/mol) + 15.999 g/mol = 18.015 g/mol
Now, we can calculate the number of moles of CO2 and H2O produced:
Number of moles of CO2 = Mass of CO2 / Molar mass of CO2 = 29.5747 g / 44.009 g/mol = 0.6719 mol (rounded to 4 decimal places)
Number of moles of H2O = Mass of H2O / Molar mass of H2O = 12.1068 g / 18.015 g/mol = 0.6720 mol (rounded to 4 decimal places)
Next, we need to determine the number of moles of carbon, hydrogen, and oxygen in the unknown compound. Since the molecular formula of the compound is unknown, we assume that the carbon in the compound ends up as CO2 and the hydrogen as H2O.
From the balanced chemical equation for combustion of hydrocarbons, we know that for every mole of CO2 produced, there is one mole of carbon involved, and for every mole of H2O produced, there are two moles of hydrogen involved.
Therefore, the number of moles of carbon = Number of moles of CO2 = 0.6719 mol
The number of moles of hydrogen = Number of moles of H2O * 2 = 0.6720 mol * 2 = 1.3440 mol (rounded to 4 decimal places)
Since we know the number of moles of carbon and hydrogen in the compound, we can now calculate the total number of moles of all elements present:
Total number of moles = Number of moles of carbon + Number of moles of hydrogen
= 0.6719 mol + 1.3440 mol = 2.0159 mol (rounded to 4 decimal places)
Finally, we can calculate the mass of oxygen produced using the mass of the unknown compound and the masses of carbon and hydrogen present:
Mass of oxygen = Total mass - Mass of carbon - Mass of hydrogen
= 10.7696 g - (0.6719 mol * 12.011 g/mol) - (1.3440 mol * 1.008 g/mol)
= 10.7696 g - 8.0710 g
= 2.6986 g (rounded to 4 decimal places)
Therefore, the mass of oxygen produced is approximately 2.6986 g, which can be rounded to 2.699 g (to 3 decimal places).