Precipitation reaction, CaCO3 and BaCO3, calcium chloride and sodium phosphate

The reaction in solution precipitation reactions considered if one
reaction products are insoluble in water. Examples of substances that are not soluble in
in water, which is CaCO3 and BaCO3.

To determine the solubility of a substance required knowledge
as a result of empirical measurement of various substances.

Consider the reaction between calcium chloride and sodium phosphate follows.
3CaCl2 + 2Na3PO4 - → Ca3 (PO4) 2 + 6NaCl
NaCl will dissolve in water, while Ca3 (PO4) 2 are insoluble.
Phosphate compounds most soluble in water, except for compounds
phosphate of sodium, potassium, and ammonium. Therefore, equation
reaction can be written as follows.

3CaCl2 (aq) + 2Na3PO4 (aq) - → Ca3 (PO4) 2 (s) + 6NaCl (aq)
By removing the ion-ion reaction spektator in equation
that, perasamaan net ion of the reaction can be obtained.
3Ca2 + (aq) + 2PO4
3 - (aq) - → Ca3 (PO4) 2 (s)


Predicting Reaction Formation
Write the molecular equation and net ionic equation of the following reactions.
Al2 (SO4) 3 + 6NaOH - → 2Al (OH) 3 + 3Na2SO4

Answer:
According to the empirical data known to soluble aluminum sulfate, whereas aluminum
insoluble hydroxide. Therefore, the precipitation reaction will occur.
Al2 (SO4) 3 (aq) + 6NaOH (aq) - → 2Al (OH) 3 (s) + 3Na2SO4 (aq)
To obtain the net ionic equation, list the substances that are dissolved as ions and
spektator ions are ignored.
2Al3 + (a) + 3SO4
2 - (aq) + 6Na + (aq) + 6OH-(aq) → 2Al (OH) 3 (s) + 6Na + (aq) +
3SO4
2 - (aq)
Thus, the following net ionic equation.
Al3 + (aq) + 3OH-(aq) - → Al (OH) 3 (s)