Dimethyl nitrosamine is a known carcinogen. It is made up of carbon, hydrogen, nitrogen, and oxygen atoms. A 4.319 g sample of dimethyl nitrosamine burned in oxygen yields 5.134 g of CO2 and 3.173 g of H2O. The compound contains 37.82% by mass of nitrogen. What is the empirical formula of dimethyl nitrosamine

C2H6N2O

Explanation:

Mass of carbon = 12g /44g/mol *  5.134 g = 1.4 g

Number of moles of carbon= 1.4 g/12g/mol = 0.12 moles

Mass of hydrogen = 2 g/18g/mol *  3.173 g = 0.35 g

Number of moles =  0.35 g/1 g/mol =  0.35

Mass of nitrogen= 37.82/100 * 4.319 g = 1.6 g

Number of moles = 1.6 g/14g/mol = 0.11

Mass of oxygen  = (4.319) - (1.4 + 0.35 + 1.635) = 0.934 g

Number of moles = 0.934 g/16 g/mol = 0.058 moles

The lowest ratio is 0.058

Dividing through;

C- 0.12/0.058 = 2

H - 0.35 / 0.058= 6

Nitrogen - 0.11/0.058 = 2

O- 0.058 moles/0.058 = 1

Hence he empirical formula is;

C2H6N2O