5) Determine the mass if lithium hydroxide that is produced when 12.87 g of lithium nitride reacts with an excess of water according to the following process:
Li, N + 3 H2O + 3 LiOH + NH,

Mass = 26.58 g

Explanation:

Given data:

Mass of lithium nitride = 12.87 g

Mass of lithium hydroxide produces = ?

Solution:

Chemical equation:

Li₃N + 3H₂O     →    3LiOH + NH₃

Number of moles of of Li₃N:

Number of moles = mass/molar mass

Number of moles = 12.87 g/ 34.83 /mol

Number of moles = 0.37 mol

now we will compare the moles of lithium nitride  with lithium hydroxide.

                  Li₃N            :            LiOH

                     1                :             3

                 0.37              :           3/1×0.37 = 1.11 mol

Mass of LiOH:

Mass = number of moles × molar mass

Mass = 1.11 mol × 23.95 g/mol

Mass = 26.58 g