Dimethylnitrosamine (CH3) 2N2O, is a carcinogenic formed in foods from nitrite ions used as preservatives. Calculate each of the following for this compound. Show all work for full credit. a. molar mass b. What is the % N

A. 74g/mol

B. 37.8%

Explanation:

A. Determination of the molar mass of dimethylnitrosamine, (CH3) 2N2O.

The molar mass of dimethylnitrosamine, (CH3) 2N2O can be obtained by adding the atomic masses of the elements present in the compound. This is illustrated below:

Molar mass of (CH3) 2N2O = 2[12 + (3x1) ] + (2x14) + 16

= 2[12 + 3] + 28 + 16

= 2[15] + 28 + 16

= 30 + 28 + 16

= 74g/mol.

B. Determination of the percentage composition of N in the compound. This is illustrated below:

There are 2 atoms of N in (CH3) 2N2O. Mass of N in (CH3) 2N2O = 2 x 14 = 28g

Mass of (CH3) 2N2O = 74g

%N = Mass of N / mass of (CH3) 2N2O x 100

%N = 28/74 x100

%N = 37.8%