# How can I calculate the percentage by mass of sodium in sodium azide, NaN3(s); used in automobile air bags?

##### 1 Answer

Jun 12, 2014

The percentage of sodium in this compound is the molar mass of sodium divided by the molar mass of sodium azide.

The molar mass (atomic weight ) of sodium is 23.0 grams/mole and the molar mass of sodium azide,

The percentage of sodium is 23.0 /65.0 x 100 % = 35 %.