Final answer:
The mass percent of carbon in decane (C10H22) is calculated by dividing the total mass of carbon in one mole by the molar mass of decane and then multiplying by 100, giving a result of 84.25%.
Step-by-step explanation:
To calculate the mass percent of carbon in decane (C10H22), you first need to calculate the molar mass of decane using the average atomic masses of carbon (C) and hydrogen (H), which are 12.01 amu and 1.01 amu respectively. Decane has 10 carbon atoms and 22 hydrogen atoms, so:
Molar mass of C10H22 = (10 × 12.01 amu) + (22 × 1.01 amu) = 120.1 amu + 22.22 amu = 142.32 amu
Next, calculate the mass percent of carbon. To do this, divide the total mass of carbon in one mole of decane by the molar mass of decane and multiply by 100%:
Mass percent of C = × 100%
Mass percent of C in C10H22 = × 100% = 84.25%