posted by Carissa on .
How do I write and balance this chemical equation as a double replacement reaction:
K2SO4(aq) + PB(NO3)2 (aq)
Think about what double replacement means. Change partners.
K of one goes with NO3 of the other.
SO4 of one goes with Pb of the other. (By the way, Pb and PB aren't the same thing)
You have to recognize that SO4-- has a charge of -2 and NO3- has a charge of -1. That will tell you that the products must be KNO3 and PbSO4.
The balanced reaction is
K2SO4(aq) + Pb(NO3)2 (aq)
-> PbSO4 + 2 KNO3
If I remember my chemistry correctly, the lead sulfate (PbSO4) is insoluble in water and will precipitate out. An arrow pointing down is often written after precipitates.