Question

What is the net ionic equation for the following reaction?

H2CrO4 + Ba(OH)2

H2CrO4– + 2OH– mc001-1.jpg CrO4– + 2H2O

2H+ + CrO4– + 2OH– mc001-2.jpg CrO4– + 2H2O

H+ + OH– mc001-3.jpg H2O

Answer 1

Write the molecular equation:
H2CrO4(aq) + Ba(OH)2(aq) → BaCrO4(s) + 2 H2O(l)

Full ionic (no spectators):
2 H+ (aq) + CrO4^2− (aq) + Ba^2+ (aq) + 2 OH− (aq) → BaCrO4(s) + 2 H2O(l)

This can be viewed as two net processes:
- Precipitation: Ba^2+ (aq) + CrO4^2− (aq) → BaCrO4(s)
- Neutralization: 2 H+ (aq) + 2 OH− (aq) → 2 H2O(l)

Either the combined ionic equation above or the precipitation equation Ba^2+ + CrO4^2− → BaCrO4(s) is an acceptable net ionic equation.