Question

Lithium is the only metal that reacts with nitrogen gas at room temperature to form lithium nitride. to avoid oxide formation, the reaction is performed under pure nitrogen gas. given the experimental data in the table below, what is the empirical formula of lithium nitride? the molar mass of lithium is 6.94 g/mol and of nitrogen is 14.01 g/mol.

Answer 1

m(Li) = 75,500 g - 74,000 g.
m(Li) = 1,500 g.
m(lithium nitride) = 76,513 g - 74,000 g.
m(lithium nitride) = 2,513 g.
m(N) = 2,513 g - 1,500 g.
m(N) = 1,013 g.
n(Li) = m(Li) ÷ M(Li).
n(Li) = 1,500 g ÷ 6,94 g/mol.
n(Li) = 0,216 mol.
n(N) = 1,013 g ÷ 14,01 g/mol.
n(N) = 0,072 mol.
n(Li) : n(N) = 0,216 mol : 0,072 mol.
n(Li) : n(N) = = 3 : 1.
The empirical formula of lithium nitride is Li₃N.