#Na_3N# decomposes to form sodium and nitrogen gas at STP. If 13.7 L of nitrogen is produced, how many moles of #Na_3N# was used (22.4 L = 1 mole of any gas) ?
First you need to write a skeleton equation and then balance it. You need to realize that nitrogen is a diatomic element
The balanced equation gives us the mole ratio of sodium nitrate to nitrogen produced: