Tests for Ions

Question 1

What is the test for carbonates?

Answer 1

• Add dilute HCl to your sample - If carbonates are present CO₂ will be released:

carbonate + acid ⇢ carbon dioxide + water

CO₃^2- _(s) + 2H⁺ _(aq) ⇢ CO_{2 (g)} + H₂O

e. g. CaCO_{3 (s)} + HCl _(aq) ⇢ CO_{2 (g)} + H₂O _(l) + CaCl_{2 (aq)}
* To prove the gas is CO₂, bubble it through limewater (goes cloudy).