What is the mass of 1.0 x 10^6 molecules of dimethylnitrosamine?

120 ag. The mass of 1.0 * 10^6 molecules of dimethylnitrosamine is 120 ag.

Step 1. Convert molecules to moles

Moles of DMN = 1.0 * 10^6 molecules DMN * (1 mol DMN) / (6.022 * 10^23 molecules DMN) = 1.66 * 10^ (-18) mol DMN

Step 2. Convert moles to grams

The formula for dimethylnitrosamine (DMN) is (CH3) 2N-N=O or C2H6N2O. The molar mass is 74.08 g/mol.

Mass of DMT = 1.66 * 10^ (-18) mol DMN * (74.08 g DMN/1 mol DMN)

= 1.2 * 10^ (-16) g DMT = 120 * 10^ (-18) g = 120 ag