Question

2NaN3=2Na+3N2. If 0.21 moles of NaN3 reacts, what mass of nitrogen would result

Answer 1

Use the mole ratio: 2 moles of NaN3 : 3 moles of N2
you have : 0.21 moles of NaN3 : x moles N2
Cross multiply: you get 0.3 moles for N2
To find the mass= # of moles * molecular mass
0.3 * 28
= 8.4g