Question

What is the percent by mass of carbon in C10 H14 N2? Use mc009-1.jpg. (A) 8.71% (B) 17.27% (C) 69.50% (D) 74.02%

Answer 1

Answer:- 74.02%

Solution:- The given compound, $C_1_0H_1_4N_2$ has 10 carbons, 14 hydrogens and two nitrogens. Mass of carbon could be calculated on multiplying it's atomic mass by 10. Similarly atomic mass of hydrogen is multiplied by 14 and atomic mass of nitrogen is multiplied by 2. Mass of carbon is divided by the molar mass that is the sum of the masses of C, H and N. To get the percentage, we multiply by 100. The calculations would be as:

mass C = 10(12.01) = 120.1

mass of H = 14(1.01) = 14.14

mass of N = 2(14.01) = 28.02

Molar mass of the compound = 120.1 + 14.14 + 28.02 = 162.26

mass percentage of C = $(\frac{120.1}{162.26})100$

= 74.02%

So, the percent by mass of carbon in the compound is 74.02%.