Lithium nitride reacts with water to produce ammonia and lithium hydroxide according to the equation
li₃n(s)+3h₂o(l)⟶nh₃(g)+3lioh(aq)
heavy water is water with the isotope deuterium in place of ordinary hydrogen, and its formula is d₂o.
the same reaction can be used to produce heavy ammonia, nd₃(g), according to the equation
li₃n(s)+3d₂o(l)⟶nd₃(g)+3liod(aq)
calculate how many grams of heavy water are required to produce 160.0 mg nd₃(g). the mass of deuterium, d, is 2.014 g/mol.

0.48 g D2O

Explanation:

Using the balanced equation we can calculate the mol and grams of heavy water required to produce the 160 mg of ND3 as follows:

Li3N (s) + 3 D2O (l) ND3 (g)  + 3 LiOD (aq)

gD2O = ?

MW ND3 = 20.04 g/mol

160 mg ND3 = 0.160 g ND3 = 0.160g /20.04g /mol =  0.08 mol ND3

1 mol ND3 needs  3 mol D2O to be produced, then

0.08 mol ND3  x 3 mol D2O/1 mol ND3 = 0.024 mol D2O

Then multiplying this number of moles by the molecular weight of D2O ( 20.028 g D2O/mol ) we will get the

0.024 mol D2O  x 20.028 g D2O/ mol = 0.48 g D2O

- lead + phosphoric acid = hydrogen + lead(ii) phosphate