Testing for CO2 (Carbon dioxide) with Limewater

To test of the presence of Carbon dioxide (CO2 in a gas) we can bubble it through a solution of limewater. If there is CO2 present it will react with the limewater to produce a milky white precipitate.
The reaction is:
CO2 (g) + Ca(OH)2 (aq) = CaCO3 (s) + H2O (l)
In the products we have CaCO3 (s). That is the precipitate and that is want causes the solution to have the milky white color.
Bubbling a gas through limewater is a common lab or demonstration in school to test for the presence of CO2. It also comes up frequently on quizzes and exams!
Related videos:
How to balance CO2 + Ca(OH)2 : • How to Balance Ca(OH)2...
Net ionic equation for: • How to Write the Net I...
CO2 + H2O: • CO2 + H2O (Carbon dio...
To recap, the limewater test is a useful tool to detect Carbon dioxide.
More chemistry at www.Breslyn.org

[@federalbureauofinvestigati2725]

He did it in one breath 👏🎉

[@wbreslyn]

I'm still recovering!

[@santumos]

I absolutely love this one. I just happen to be making spreadsheets about the carbonate buffer system. Thanks for the upload.

[@santumos]

May I know the initial concentration of Ca(OH)2 or the initial pH?

[@wbreslyn]

It's a saturated solution of Ca(OH)2 but Calcium hydroxide isn't very soluble, so not much is dissolved. It was about 20C when I made the solution so: 1.89 g/L (0 °C) 1.73 g/L (20 °C) 0.66 g/L (100 °C) (retrograde solubility, i.e., unusually decreasing with T) Data from en.wikipedia.org/wiki/Calcium_hydroxide

[@wbreslyn]

You're welcome!

[@santumos]

@@wbreslyn thank you!

[@shahmir5445]

that is NOT one breath bro 😭

[@fatmakhan7776]

Yes it is not

[@Juniorkforce]

We don't care bro at last it helped us bro

[@shahmir5445]

@@Juniorkforce My sincere apologies good sir. By any means, in any way, shape or form, I did not try to offend your gracious self with my stupendously illiterate and immature statement. I hope you will forgive me, as you have sent me unto an abyssal void of regret.

[@Juniorkforce]

@@shahmir5445 I forgive but don't do that again

[@shahmir5445]

@@Juniorkforce Or else what?

[@ivanvalverde7018]

Long exhale, incredible.

[@wbreslyn]

Thanks!

[@lil_ant5604]

will you please do a reaction for heating potassium carbonate with lime water? I love your videos! ❤

[@wbreslyn]

Great suggestion! I'll put it on my list.

[@ashuashu3618]

Evaluation: Diagram. Labelling. Ans. = Yaha Kia likhna hoga pls reply me

[@ladorani6689]

I love the way you explain 💗

[@Isaac_Payne]

POV gayyyyyy

[@sandlewould5359]

If the supply of CO² (g) is continued then after a point ...the white colour disappears due to the formation of water soluble Ca(HCO³)² (aq.). Keep on bringing them sir.

[@wbreslyn]

Yes, you are correct! I did that in a test-tube and it worked rather well. Using the larger flask I've found that it takes quite a long time. Perhaps if I generated CO2 and bubbled it through the flask that would work. The CO2 would be more concentrated than in my breath. Perhaps I'll do a video on that!

[@mycoverse1]

Question: before it decomposes into Calcium Carbonate, does it not first become soluble Calcium Bicarbonate before it precipitates the insoluble carbonate?

[@polytrichum1119]

Wow!Thats amazing!Is it possible to make Ca(OH)2 without hydrochloric acid but with heating CaCO3 to turn it into CaO and then dissolve CaO in water,making Ca(OH)2?

[@VideoCollector138]

underated

[@wbreslyn]

Thanks!

[@lightcapmath2777]

Question: can the garden supply store that sells lime work as well? yes after HOH is added..distilled? This type of "intro to chemistry" is easy and make participants engage and excite the student to learn chem...Peace DVD:)

[@wbreslyn]

I'm not sure. I actually bought the Ca(OH)2 in a form used for baking. It's much cheaper and works very well.

[@lightcapmath2777]

@@wbreslyn Ummm will give it a try...Many thanks Dr. B D:)

[@janani478]

Thank you man❤

[@anupamchakrabarti4657]

You have a nice pair of lungs, Sir! Nice explanation.

[@wbreslyn]

Thank you kindly!

[@davidhammond1198]

Dr. B, Is this the exact same reaction that people are hoping for when they talk about adding carbonates and silicates to the sea as a way to absorb CO2 from the atmosphere? The approach is termed Ocean Alkalinity Enhancement. If you don't mind, can you spell out those reactions? Thank you!

[@wbreslyn]

Quiet similar, although OAE would likely use the most cost effective materials to generate the OH- ions. And the ocean is a rather complex situation. But the concept, and the chemistry, is similar.

[@jonerasmus9399]

Also; in excess CO2 . The ppt disappears to form calcium hydrogen carbonate

[@jadorre]

thank u

[@jerredanugot3064]

Is there a way to bubble CO2 without making it in contact with the liquid?

[@servofyah4392]

Can calcium oxide be turned back to calcium carbonate?

[@kavyasree135]

Thanks u 😊

[@ahmedader4283]

We want nernest equation and faradays laws in electro chemistry plz🙏✅

[@wbreslyn]

I'll put it on my list!

[@ashuashu3618]

Acha Isme Jo Evaluation: Diagram. Labelling. Ans. = Ye kia hai

[@FarooqTak]

Is this endothermic or exothermic

[@rajeswari4091]

How CO2 can be passed like from wht source?..plz rply

[@wbreslyn]

In this case it was from me exhaling through the tube in the video (the CO2 in my exhaled breath). But you could also put dry ice (solid/frozen CO2) in the solution and that would work as well. Or any other source of CO2 would turn the limewater cloudy white.

[@rajeswari4091]

@@wbreslyn Thanks 😊 a lot

[@mannanali3270]

What is the meaning of (g)

[@uselessvids6407]

Gas

[@r7a_a]

zn+h2so4=znso4+h2 oxidation Plzz I have exam after 2hrs

[@wbreslyn]

I'm probably too late but ... you need to look at the oxidation numbers. Zn in the reactants is a free element so it is zero. In the products it is bonded to the sulfate ion so we have ZnSO4. Here is has a +2 oxidation number. So since it went from 0 to +2 it lost electrons. That means it was oxidized. Finding Oxidation Numbers: kzbin.info/www/bejne/n4SkqHeAibF8gbs

[@AnilKumarsingh-fe9zm]

Crazy

[@wbreslyn]

Indeed!

[@Nixkip]

can i drink it doe

[@wbreslyn]

If all of the Ca(OH)2 has been converted to CaCO3 then I would expect it wouldn't be a problem. Still, I wouldn't recommend drinking it!

[@snoopyr1953]

nice lungs you have there!

[@FifiMolale]

That ain't one breath tho(all the way from Africa)😭

[@wbreslyn]

It is but remember it is going through a small tube, so not much air is actually coming out compared to the 4 or so liters an adult human can exhale.

[@6afrends]

buld