What mass of water is needed to react with 32.9 g Li3N?

The answer to your question is 50.76 g of H₂O

Explanation:

Data

mass of water = ?

mass of Li₃N = 32.9 g

Process

1.- Write the balanced chemical reaction

                    Li₃N  +  3H₂O   ⇒  3LiOH   +  NH₃

2.- Calculate the molar mass of Li₃N and H₂O

Li₃N = (3 x 7) + (1 x 14) = 35 g

H₂O = (2 x 1) + (16 x 1) = 18 g

3.- Use proportions to calculate the mass of water

                   35 g of Li₃N (3 x 18) g of water

                    32.9 g of Li₃N x

                    x = (32.9 x 54)/35

                    x = 1776.6/35

                    x = 50.76 g of H₂O