Final answer:
The mass percent of carbon in C14H19NO₂ is approximately 72.05%, which is calculated by dividing the total mass of carbon in the compound by the compound's molar mass and multiplying by 100 percent.
Step-by-step explanation:
The question asks for the mass percent of carbon in the molecular formula C14H19NO₂. To find the mass percent of carbon, you need to calculate the total mass of carbon atoms in the formula and then divide that by the molar mass of the entire compound.
The molar mass of carbon (C) is about 12.01 g/mol. Since there are 14 carbon atoms in C14H19NO₂, the total mass of carbon is 14 × 12.01 g/mol = 168.14 g/mol. Next, you need to calculate the molar mass of the entire compound: C14H19NO₂. The molar masses of hydrogen (H), nitrogen (N), and oxygen (O) are approximately 1.01 g/mol, 14.01 g/mol, and 16.00 g/mol, respectively. Therefore, the molar mass of C14H19NO₂ is:
14 × 12.01 g/mol (carbon) + 19 × 1.01 g/mol (hydrogen) + 1 × 14.01 g/mol (nitrogen) + 2 × 16.00 g/mol (oxygen) = 168.14 g/mol (C) + 19.19 g/mol (H) + 14.01 g/mol (N) + 32.00 g/mol (O) = 233.34 g/mol
Finally, to find the mass percent of carbon in the compound, divide the total mass of carbon by the molar mass of the compound and multiply by 100 percent:
Mass percent of carbon = (168.14 g/mol / 233.34 g/mol) × 100% ≈ 72.05%