How to Predict Products – The Process What new compounds are possible from this set of four ions ion solution?
Since cations must always pair with anions, only two new compounds are possible. The potassium ions can pair up with the nitrate ions and the barium ions can pair up with the sulfate ions. It is very important to remember what we learned in Objective 5 – all ionic compounds must have a zero net charge. Whatever precipitate you form, it must have a zero net charge. The possible compounds would then be BaSO4 and KNO3. In order for this to be a precipitation reaction, one of your products must be an insoluble compound. Check your solubility table to see if either barium sulfate or potassium nitrate (your possible products) are insoluble in water. You will see that barium sulfate is insoluble in water. Therefore, when barium and sulfate ions come together in the aqueous solution, they will form a solid and precipitate out. Potassium nitrate is a soluble compound. Therefore, these ions will remain in solution.
