indicators! (1 Viewer)

[serge]

Are you trying to use these as indicators?
Or is this what you are testing?

citric acid- found in lemon/orange juice
is 2-hydroxypropane,1,2,3- tricarboxylic acid (its written in the syllabus)

sugar water... should be glucose(aq)
glucose being C6H12O6

 

[babydoll~*]

you know how the first dot point asks for the names of substances and then a formula??

ive put sugar water and orange juice for two of my substances....

but ive forgotton what the formula is for oj and for sugar water, im a bit lost..

 

[kami]

So are you asking which indicator should be used to identify each substance?
bromothymol blue is sensitive around the neutral range
phenolphthalein is best in the basic range(eg soaps and detergents)
methyl orange is best in the acidic range(eg acetic acid-vinegar or citric acid as found in fruits)g detergents and soaps)

 

[babydoll~*]

finally! =)

ahh no I meant that as in your using an indicator to identify common substances !

egh.. one more..? vinegar -_-

 

[serge]

vingegar (acetic acid) CH3COOH
Kami's already mentioned the indicator you need

 

[jarro_2783]

to answer the actual question they are what you are testing. You need an indicator to test them. I would be using universal indicator solution since it covers the whole range.

 

[Dreamerish*~]

to answer the actual question they are what you are testing. You need an indicator to test them. I would be using universal indicator solution since it covers the whole range.

Universal indicator is not in the course.

It's not wrong to use it, but it would be kind of difficult to remember all the colours corresponding to their pHs.

For citric and acetic acid, methyl orange can be used. It is able to distinguish between strong and weak acids (although both citric and acetic are weak).

The ranges of indicators are:

• Litmus: pH 5 - 8, red - blue
• Phenothalein: pH 8.3 - 10, clear (not grey ) - magenta/purple
• Methyl Orange: pH 3.1 - 4.4, red - yellow
• Bromothymol Blue: pH 6.2 - 7.6, yellow - blue