Consider the equation: 2 nan3 (s) 2 na (s) + 3 n2. what is the mass of nan3 needed to produce 17.2 l nitrogen at stp?

The mass of NaN3 needed to produce 17.2 L nitrogen at STP is calculated as follows

find the moles of N2 produced at STP

At STP 1mole of gas = 22.4 L, what about 17.2 L of nitrogen

by cross multiplication

= (1 mole x17.2 L) / 22.4 L = 0.768 moles

2NaN3 = 2Na + 3 N2

by use of mole ratio between NaN3 to N2 (2:3) the moles of NaN3 = 0.768 x2/3 = 0.512 moles of NaN3

mass of NaN3 is therefore = moles of NaN3 xmolar mass of NaN3

=0.512moles x 65 g/mol = 33.28 grams of NaN3