Citric Acid. (1 Viewer)

[The Matrix]

Why is citric acid triprotic? What other acids are triprotic other than citric and H3PO4.
Can anyone please list the names of the acids/bases/esters for which we have to memorise the structural formula i.e. knowing the molecular formula (C6H8O7) wouldn't help in classifying citric acid as a triprotic, we have to know the structural formula to know it is triprotic

Thanks

 

[golgo13]

The protic section means the ability to give away it's h and to continue to do so:
Some examples
Monoprotic: HCl (can only give away one H) 1 step process
Diprotic: H2S04 (has the ability to protonate once into HS04- then again into SO42-) 2 step process
Triprotic:H3PO4( can protonate 3 times [H2PO4- HPO4-2, PO4-3]) 3 step process

For any others not sure, but quite sure they will give it to u, they're not that mean, unless it's school examinations in which case you're at the mercy of ur teacher

 

[The Matrix]

I know why things are called mono, di, tri protic...
That's not the question my friend.

 

[BL3H]

I know why things are called mono, di, tri protic...
That's not the question my friend.

Why is citric acid triprotic? What other acids are triprotic other than citric and H3PO4.
Can anyone please list the names of the acids/bases/esters for which we have to memorise the structural formula i.e. knowing the molecular formula (C6H8O7) wouldn't help in classifying citric acid as a triprotic, we have to know the structural formula to know it is triprotic

Thanks

It's kind of exactly what you asked.

You should memorise the ones in the syllabus dot-point that it says to "identify" (I think it says that) which are citric, hydrochloric, and sulphuric, but I'd say remember acetic (and maybe other common ones) as well.

 

[golgo13]

I know why things are called mono, di, tri protic...
That's not the question my friend.

Your question above asked why, i answered why

 

[The Matrix]

Sorry for the wording of my question.
I was asking about how we identify them. The only way to identify weird ones is to know the structural formula e.g. citric acid. So I was asking for which acids/basis/esters do we need to be familiar with the structural formula in order to be able to identify them

 

[golgo13]

Same answer there's a pattern in my answer. HSC doesn't take the question out of proportion, Basically bases will generally be OH with a fancy bit in front. The acids mines citric and acetic i think the rest is quite standard and esters u just need to look for the coo bit in the middle hope that clears it up

 

[The Matrix]

These are the main ones, I think. And esters are easy CnH2nO2 and put the COO in the middle.
Acid Mono: HCl, HNO3, CH3COOH
Acid Di:Sulfuric acid, Carbonic acid, chromic acid, oxalic acid, sulfurous acid, glycine, hydrogen sulfide
Acid Tri: Phosphoric acid, Citric Acid,

Base Mono: KOH, NaOH, NH3
Base Di: Barium hydroxide , , ,
Base Tri: Phosphate ion, Sulfate ion, , ,

 

[golgo13]

TBH i wouldn't be concerned to remember them off by hard, unless your trials are home brewed like ruse papers. Independent trials and Catholic papers are quite stock. Although some of it is rote learn this section should be quite cautious, the theory isn't as important because from memory this only relates to a calculation and maybe if your unlucky a theory. But having said that do what works best for you, but my advice is just accept what is given

 

[The Matrix]

No need to memorise anything, I actually know the theory behind everything, thanks to dp notes...
I hate rote learning.