Using Precipitation to Test for Ions

Question 1

What happen to calcium ions (Ca(2+)) when in the ocean?

Answer 1

They combine with carbonate ions (CO(3)(2+)), or limestone

Question 2

What are the insoluble solids that are formed in these reactions known as?

Answer 2

Precipitates

Question 3

What is the use of precipitates?

Answer 3

We can use precipitation reactions to detect ions in aqueous solutions

Question 4

How can we made predictions about precipitation reactions?

Answer 4

By interpreting information on solubility.

Question 5

Give an example of this

Answer 5

If we know that magnesium carbonate is insoluble, then mixing a solution that contains magnesium ions (eg. magnesium chloride) with a solution that contains carbonate ions (eg. sodium carbonate) will results in the precipitation of insoluble magnesium carbonate.