Tests for HCO3- ions

On a past Edexcel 3A paper, there is a test for a hydrogen carbonate ion which reads:

"Dissolve half of the remainder of solid A in about 5cm3 of water and add 4 drops of phenolphthalein indicator. Seperate the solution into two equal portions and boil one gently for two minutes."

Has anybody come across this test before? The only tests for HCO3 I've come across are the limewater test, and adding MgSO4 to solutions of carbonate and hydrogen carbonate to distinguish between them. I've also googled it, but can't see to find anything else except for
"Test for hydrogen carbonate ion, HCO3-. Known solution is sodium hydrogen carbonate. Carefully observe the test tubes as you add 2mL of 6M hydrochloric acid to each tube. Record observations."

Would appreciate any info!

Reply 1

Abbas6

...Any ideas anyone? :confused:

Reply 2

tkane

abbasi

...Any ideas anyone? :confused:

Reply 3

Yilin510

I just think to solve this question from boil one solution gentle for two minutes

Add HCl?

Anyone ???

Reply 4

Borek

Boling converts HCO3(-) into CO3(2-), due to hydrolysis pH goes up. Adding HCl you will lower pH (color change) and force carbon dioxide out of solution.

Best,
Borek
--