Explore BrainMass

Balancing an Equation

Which is correctly balanced?
A. H3PO4 + NaOH --> Na3PO4 + 3H2O
B. 2SO2 + O2 --> 2SO3
C. 2Na + 2H2O --> H2 + 2NaOH
D. CS2 + 2H2 --> 2H2S + CH4

Solution Preview

A. H3PO4 + NaOH --> Na3PO4 + 3H2O

This is not balanced. We must place a 3 in front of the NaOH in order to balance out the Na, O and H on both sides. Thus

H3PO4 + 3 NaOH --> Na3PO4 + 3H2O ...

Solution Summary

Balanced reactions must have the same number of atoms of elements on both sides of the reaction.