Tests for Carbonates using Hydrochloric Acid

Question 1

Describe the process to test for carbonates using hydrochloric acid.

Answer 1

1. Add dilute hydrochloric acid to the sample.
2. Test for carbon dioxide given off.

Question 2

Ionic equation for the reaction using carbonates and hydrochloric acid.

Answer 2

CO₃^2-_(aq) + 2H⁺_(aq) —> CO_2(aq) + H₂O_(l)

Question 3

Describe the process to test for CO₂ in the test for carbonates using hydrochloric acid.

Answer 3

1. Attach a delivery tube connecting the test tube containing the sample and a test tube containing limewater (calcium hydroxide, Ca(OH)₂)
2. Observe colour of limewater

Positive test result: limewater turns cloudy