Uses of indicators (1 Viewer)

[2006hsc]

What are some uses at home or in industries for the following indicators
methyl orange
bromothymol blue
litmus
phenolphthalein

the textbook has no uses for each specific indicator

and also how do indicators change colour?

 

[pLuvia]

Litmus and bromothymol blue is used to test whether a solution is acidic, neutral or alkaline and we use methyl orange or phenolphthalein to test whether something is highly or slightly acidic or alkaline respectively

Some practical uses are
Testing acidity or alkalinity of soils
Monitoring wastes from laboratories that process photographic film
Testing swimming pools

Colour Change
~~~~~~~~~~~~~~Highly acidic~~Slightly acidic~~Neutral~~~slightly basic~~highly basic
methyl orange~~~~~~ red ----------> yellow~~~~~ yellow~~~~~yellow~~~~~yellow
bromothymol blue~~~~yellow~~~~~ yellow -------------------------> blue~~~~~~~~ blue
litmus~~~~~~~~~~~~ red~~~~~~~red -----------------------------> blue~~~~~~~~~blue
phenophthalein~~~~colourless~~~~colourless~~~colourless~~colourless ---> red

Edited: methyl orange or phenolphthalein to test whether something is highly or slightly acidic or alkaline respectively
Edited 2: Litmus and bromothymol is used to measure whether something is acidic, neutral or basic

Sorry about the confusion (again)

 

[2006hsc]

For the practical uses that you listed, which indicators would best suit them..or would all be acceptable testing them?

 

[Dreamerish*~]

Methyl orange and bromothymol blue is used to test whether a solution is acidic, neutral or alkaline and we use methyl orange and phenolphthalein to test whether something is highly acidic or slightly alkaline

Some practical uses are
Testing acidity or alkalinity of soils
Monitoring wastes from laboratories that process photographic film
Testing swimming pools

Just a correction: phenolphthalein is used to test whether something is slightly or highly alkaline.

An example for testing soils would be hydrangea flowers. They are pink in basic soil and blue in acidic soil - exactly the opposite of litmus!

 

[2006hsc]

Methyl orange and bromothymol blue is used to test whether a solution is acidic, neutral or alkaline and we use methyl orange and phenolphthalein to test whether something is highly acidic or slightly alkaline

Some practical uses are
Testing acidity or alkalinity of soils
Monitoring wastes from laboratories that process photographic film
Testing swimming pools

Colour Change

~~~~~~~~~~~~~~Highly acidic Slightly acidic Neutral slightly basic highly basic
methyl orange~~~~~~ red ----------> yellow yellow yellow yellow
bromothymol blue~~~~yellow yellow --------------------> blue blue
litmus~~~~~~~~~~~~ red red -----------------------> blue blue
phenophthalein~~~~colourless colourless colourless colourless ---> red

thanks mate you have been tremendously helpful

 

[2006hsc]

when u said "methyl orange and bromethyl blue is used to test whether a solution is acidic, neutral or alkaline", did u mean use both of them on the same test? because i dont see how methyl orange indicator by itself can determine if something is neutral

 

[Dreamerish*~]

when u said "methyl orange and bromethyl blue is used to test whether a solution is acidic, neutral or alkaline", did u mean use both of them on the same test? because i dont see how methyl orange indicator by itself can determine if something is neutral

Methyl Orange is useful in distinguishing between slightly acidic and strongly acidic substances, while Bromothymol Blue is used to distinguish between acidic, neutral and basic substances.

 

[pLuvia]

when u said "methyl orange and bromethyl blue is used to test whether a solution is acidic, neutral or alkaline", did u mean use both of them on the same test? because i dont see how methyl orange indicator by itself can determine if something is neutral

Sorry about that editted, it was a typo. I was meant to say litmus and bromothymol blue sorry

 

[dhampoet]

what is the order of the best indicator for all range (base,neutral,acid) between cabbage,methyl orange,bromo blue,universal anyway?
universal will be the top indeed

 

[Forbidden.]

Just a correction: phenolphthalein is used to test whether something is slightly or highly alkaline.

An example for testing soils would be hydrangea flowers. They are pink in basic soil and blue in acidic soil - exactly the opposite of litmus!

I thought it was azaleas that did that.

what is the order of the best indicator for all range (base,neutral,acid) between cabbage,methyl orange,bromo blue,universal anyway?
universal will be the top indeed

You could say that, but in the HSC you gotta be familiar with a few more than that.