How many grams of lithium are needed to produce 45.0g of lithium nitride?

              26.899 g of Li

Solution:

The Balance Chemical Equation for given reaction is as follow;

                                         6 Li  +  N₂    →    2 Li₃N

According to equation,

                 69.66 g (2 mol) Li₃N is produced by  =  41.64 g (6 mol) of Li

So,

                    45.0 g of Li₃N will be produced by  =  X g of Li

Solving for X,

                      X =  (45.0 g × 41.64 g) ÷ 69.66 g

                      X  =  26.899 g of Li

Hence, 26.9 g of Lithium is required to produce 45.0 g of Lithium Nitride.