Question

Give the mass percent of nitrogen in C14H19NO2.

Answer 1

Answer:

The mass percent of carbon in C₁₄H₁₉NO₂ is 72.1%.

Explanation:

To calculate the mass percent of carbon in C₁₄H₁₉NO₂ we have to follow two simple steps:

1st) Look for the atomic weight of each element in the Periodic Table and then multiply each one by its subscript in the molecule and finally sum all of them to find the molar weight of the molecule:

Carbon atomic weight . Carbon subscript = 12 . 14 = 168g

Hydrogen atomic weight . Hydrogen subscript = 1 . 19 = 19g

Nitrogen atomic weight . Nitrogen subscript = 14 . 1 = 14g

Oxygen atomic weight . Oxygen subscript = 16 . 2 = 32g

The molar weight of C₁₄H₁₉NO₂ is: 168g + 19g + 14g +32g = 233g.

2nd) Find the mass percent of carbon with a Rule of three:

If 233g represents the 100% of mass, the 168g of carbon in the molecule will represents the 72.1% of mass.

The Rule of three is:

233g ------------- 100%

168g ------------- = (168 . 100)/233 = 72.1% mass of carbon.