Question

Ammonia can be prepared by the reaction of magnesium nitride with water. The products are ammonia and magnesium hydroxide. When the equation is written and balanced, the coefficient of water is

1. 3
2. 2.
3. 6.
4. 1.

Answer 1

Answer:

Mg₃N₂ + 6H₂O  →  2NH₃  +  3Mg(OH)₂

Coefficient of water is 6 (option 3)

Explanation:

The reaction is:

Mg₃N₂ + H₂O  →  NH₃  +  Mg(OH)₂

Let's balance the reaction.

In reactant side we have 3 Mg, therefore in product side, we add 3 Mg to the hydroxide.

This change, modified the hydroxide, so now we have 6 O and 6 H, but we have in total 9 H (6 from the hydroxide + 3 from the ammonia)

As we have 2N, in reactant side, we must add 2 N to the ammonia, so now

we have 12 H in product side . We must complete with 6, the water so the H are ballanced.

In reactant side we have 6 O, therefore in product we must have 6 O (two O, in the OH but we have 3 moles, so in total we have 6 O) - BALANCED

The balance reaction is:

Mg₃N₂ + 6H₂O  →  2NH₃  +  3Mg(OH)₂