Ammonia can be made by reaction of water with magnesium nitride: __ Mg3N2 (s) + __ H2O (l) → __ Mg (OH) 2 (s) + __ NH3 (g) When the equation is properly balanced, the sum of the coefficients is

Mg3N2 (s) + 6H2O (l) → 3Mg (OH) 2 (s) + 2NH3 (g)

Explanation:

Step 1: Data given

ammonia = NH3

water = H2O

magnesium nitride = Mg3N2

Step 2: The unbalanced equation

Mg3N2 (s) + H2O (l) → Mg (OH) 2 (s) + NH3 (g)

Step 3: Balancing the equation

On the left side we have 3x Mg (in Mg3N2), on the right side we have 1x Mg (in Mg (OH) 2).

To balance the amount of Mg, we have to multiply Mg (OH) 2 by 3

Mg3N2 (s) + H2O (l) → 3Mg (OH) 2 (s) + NH3 (g)

On the left side we have 2x N (in Mg3N2), on the right side we have 1x N (in NH3). To balance the amount of N, we have to multiply NH3 by 2

Mg3N2 (s) + H2O (l) → 3Mg (OH) 2 (s) + 2NH3 (g)

On the left side we have 2x H (in H2O), on the right side we have 12x H (6x in Mg (OH) 2 and 6x in NH3). To balance the amount of H we have to multiply H2O (on the left side), by 6.

Now the equation is balanced.

Mg3N2 (s) + 6H2O (l) → 3Mg (OH) 2 (s) + 2NH3 (g)