indicators range/color (1 Viewer)

[Managore]

bromo blue, methyl orange, phynophalin (cant spell)

What are the range/color changes of these? Do we need to remember this?

 

[Tommy_Lamp]

Yes, because you need to know which indicator to use in a titration.
Phenolphthalien colour change occurs in the basic range
Bromothymol Blue occurs in the neutral
Methyl acidic

The last 2 might be mixed up

 

[sub]

bromothymol blue is about 6-7, methyl orange is 3.1-4.4 ?, phenophthalein is at 9.

pls correct me if im wrong.

and yes u DO need to know this

 

[Managore]

What about color changes? is there any way of remembering all of this?

 

[sub]

uhhh, correct me if im rong cos most likely i am, but

bromo blue is yellow in acid, blue in base, methyl orange is red in acid, yellow in base, pheno is colourless in acid pH < 9, and red/pink pH >9.

not sure abt bromo blue and methyl...u should kno litmus by now...think yr 7 chem

 

[Paroissien]

Methyl: red ---> yellow
Bromo: yellow ---> blue
Pheno: colourless ---> red
Litmus: red ---> blue