What is colour of neutral in methyl orange? (1 Viewer)

[enigma_1]

I'm seeing different things in different textbooks. Is it yellow or orange?

 

[QZP]

Methyl orange in its natural state is orange. It has a pH range of ~3.0 - 4.0 Thus, a neutral solution would turn methyl orange yellow.

 

[enigma_1]

Ok so below pH 3.1, methyl orange becomes red. Above 4.4 methyl orange goes yellow and in its transition range (31. --> 4.4) it is yellow?

Is that all correct?

 

[QZP]

Are you saying that between 3.1 - 4.4 it is yellow, and that also 4.4+ is yellow?

 

[enigma_1]

Yeah, is that right though?

 

[QZP]

If 3.1 - 4.4 is yellow, and 4.4+ is yellow, then wouldn't 3.1+ be yellow? Doesn't really make sense does it

 

[anomalousdecay]

Going off this if the pH of solution is:

pH < 3.1, then Methyl Orange is Red.

3.1< pH < 4.4, then the Methyl Orange is Orange.

pH > 4.4 then the Methyl Orange is Yellow.

 

[pHyRe]

this guy has it correct ^

 

[QZP]

Yeah I'm still curious about how you thought 3.1 - 4.4 is yellow, and then also 4.4+ is yellow.

 

[anomalousdecay]

Yeah I'm still curious about how you thought 3.1 - 4.4 is yellow, and then also 4.4+ is yellow.

For some indicators like Methyl Orange, the colour change is slow as yellow and red are exhibited in the middle to produce orange.

However, with something like phenolphthalein, there is a rapid change of colour from colourless to pink. However, from doing some titrations using this indicator, I found out that it still happens over quite a range, going from light pink to a very dark and vivid pink.

So generally, you must remember that with titrations, the colour change is gradual. You won't go instantly from red to yellow.

Or in the case of Bromothymol Blue for example, you won't go from blue straight to yellow instantly. Instead it will go from blue to green then to yellow (as a little blue and a little yellow together makes green).