The Colourful World Of Indicators

If you dont have sodium hydroxide and sulphuric acid then you could use vinegar and washing soda. Although you will not be able to reach the very high and very low pHs, but is isen too bad.

Just a few things about indicators, acid and bases.


A chemical is not an acid (or base), nothing is inherently one thing or another. An acid or base is defined by the reaction taking place. There are two basic definition of the acid. Theres the Brønsted-Lowry acid which is a proton (H+) donor and the Lewis acid which is a loin pair (electrons) acceptor.
For example; hydrogen chloride gas is bubble through water. The H Cl bond brakes and the molecule is ionized into a H+ and a Cl-. The HCl is adding H+ ions to the water so its a Brønsted-Lowry acid. And the water is acting as the base because its a proton excerptor. This is the classic example of a acid reaction but there are other reactions to look out for.

An indicator is usually a large organic molecule (with a few double bonds here and there, also an aromatic system). When protons are added (acid) or removed (basic) then this changes the electronic environment of the molecule. As such this changes the kinds of wavelength of light that can be absorbed. So this changes the colour.

I am thinking about doing a video on these ideas plus buffers but I will only do it if there is interest. (I would hate to bore you (even though is an interesting subject! (Well I think so( :D )))))

Category:

Education

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[adjuvants12780]

will methanol work as a solvent rather than ethanol?

cause my mom does not feel like giving up her stash....

[AlchemicalGarden]

@adjuvants12780 yes probebly, you could try a 50/50 mix methanol and water

[nshoebox]

Whooo, I never know tea could be used!

Could you tell me what kind of tea your used, and would you know what chemical in tea make the colors changes when adding acids and bases?

[AlchemicalGarden]

just normal tea

dont know about the chemical/s. its probebly a mix of oragnic ones

[OrganicWebhead]

This is one AWESOME video. Thanks for sharing, i hope you do a video on those ideas you talked about on the infobox.

ohh, and btw, really nice explanation in the infobox about acids and bases. Nice work =)

[AlchemicalGarden]

well i shall get right on it then.

[98JMA]

Where do you buy your glassware i.e. conical flasks etc. from??

[ConnellDaneLaurance]

Wouldn't it be better to have the acid in the burette?

[spotlightman1234]

@fossil98 I'm 14 and o even have vodka lol ( only for expirements of course vodka tastes like crap)

[phlexonance]

My favourite indicator is Tashiro (Methylred + Methylorange), I just loove saying that ^^ Tashiro!

[adjuvants12780]

@AlchemicalGarden thx man, btw i love all your vids, keep it up!

[Cforchemistry]

The indicators you used are very fantastic, great vids!