Calculate the % by mass of carbon in octane
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To calculate the percentage by mass of carbon in octane, we need to know the molecular formula of octane. Octane is an organic compound with the molecular formula C8H18. This formula tells us that each molecule of octane contains 8 carbon atoms.
To calculate the percentage by mass of carbon, we need to know the molar mass of carbon and the molar mass of octane.
The molar mass of carbon (C) is approximately 12.01 g/mol. Since there are 8 carbon atoms in octane, the mass of carbon in one molecule of octane would be 8 * 12.01 = 96.08 g/mol.
The molar mass of octane (C8H18) can be calculated by adding up the atomic masses of all the atoms in the molecule:
(8 * 12.01) + (18 * 1.01) = 114.22 g/mol
Finally, to calculate the percentage by mass of carbon in octane, we divide the mass of carbon by the molar mass of octane and multiply by 100:
(96.08 g/mol / 114.22 g/mol) * 100 = 84.2%
Therefore, the percentage by mass of carbon in octane is approximately 84.2%.