Lithium nitride reacts with water to produce ammonia and lithium hydroxide according to the equation Li 3 N ( s ) + 3 H 2 O ( l ) ⟶ NH 3 ( g ) + 3 LiOH ( aq ) Heavy water is water with the isotope deuterium in place of ordinary hydrogen, and its formula is D 2 O . The same reaction can be used to produce heavy ammonia, ND 3 ( g ) , according to the equation Li 3 N ( s ) + 3 D 2 O ( l ) ⟶ ND 3 ( g ) + 3 LiOD ( aq ) Calculate how many grams of heavy water are required to produce 320.0 mg ND 3 ( g ) . The mass of deuterium, D , is 2.014 g/mol.

The mass of   needed is 0.96 grams

Explanation:

To calculate the number of moles, we use the equation:

    .....(1)

Given mass of = 320.0 mg = 0.320 g   (Conversion factor:  1 g = 1000 mg)

Molar mass of = 20 g/mol

Putting values in equation 1, we get:

For the given chemical equation:

By Stoichiometry of the reaction:

1 mole of is produced from 3 moles of

So, 0.016 moles of will be produced from = of

Now, calculating the mass of   from equation 1, we get:

Molar mass of  = 20 g/mol

Moles of   = 0.048 moles

Putting values in equation 1, we get:

Hence, the mass of   needed is 0.96 grams