How would you balance this equation: #?H_3PO_4 + ?Mg(OH)_2 -> ? Mg_3(PO_4)_2 + ? H_2O#?

1 Answer
Nov 1, 2016

#2 H_3PO_4 + 3 Mg(OH)_2 -> Mg_3(PO_4)_2 + 6 H_2O#

Explanation:

To do it, I took the following steps :

  • Balance Mg:

I have 3 Mg in #Mg_3(PO_4)_2# so I added 3 on the other side #3 Mg(OH)_2#

  • Balance P :

Again I have 2 P in #Mg_3(PO_4)_2# so I added 2 on the other side #2 H_3PO_4#

  • Balance H :

I have 6 H in #2 H_3PO_4# #(2xx3) # and 6 H in #3 Mg(OH)_2# a total of 12 H so I added 6 next to #H_2O#
#6 H_2O#

Notice that the O is automatically balanced : 8 O in #2 H_3PO_4# + 6 O in #3 Mg(OH)_2# = 8 O in #Mg_3(PO_4)_2# + 6 O in #6 H_2O#

I hope that was clear