Acids as proton donors (1 Viewer)

[Snowflek]

Hey guys, I understand that acids are protons donors and i have a question about it. Citric acid (2hydroxypropane 1,2,3 tricaboxylic acid) is a triprotic acid. For an acid to donate a proton, it should be attached to a electronegative molecule (correct me if im wrong, i saw this somewhere) such as the O-H, which the O wil have the electron on its side for most of the time, hence, the hydrogen can be donated without the electron. So based on that knowledge, citric acid has a carboxyl group which has the O-H, meaning that it is able to donate an electron, resulting in 3 donation. Also, on the second carbon, it also has a O-H of the hydroxyl group meaning it can donate a hydrogen ion again? Doesnt this allow citric to donate 4 protons? I'm extremely confused and need an explanation to see if what i understand is wrong. Thank you

Also, another question. CaCo3 + HCL --> CaCl2 + CO2 + H2O
I thought it was CaCo3 + HCL --> CaCl2 + H2Co3 or something. Clearly i dont remember/understand the rule. Can someone regurgitate the rule for me again? ( or specify which dotpoint in the syllabus this was in if you arent bothered to) Thank you!

 

[cloud edwards]

Dunno about the first question.
For the second question when you have a carbonate + acid it generally goes to= salt + water + carbon dioxide

 

[Fizzy_Cyst]

Hey guys, I understand that acids are protons donors and i have a question about it. Citric acid (2hydroxypropane 1,2,3 tricaboxylic acid) is a triprotic acid. For an acid to donate a proton, it should be attached to a electronegative molecule (correct me if im wrong, i saw this somewhere) such as the O-H, which the O wil have the electron on its side for most of the time, hence, the hydrogen can be donated without the electron. So based on that knowledge, citric acid has a carboxyl group which has the O-H, meaning that it is able to donate an electron, resulting in 3 donation. Also, on the second carbon, it also has a O-H of the hydroxyl group meaning it can donate a hydrogen ion again? Doesnt this allow citric to donate 4 protons? I'm extremely confused and need an explanation to see if what i understand is wrong. Thank you

Also, another question. CaCo3 + HCL --> CaCl2 + CO2 + H2O
I thought it was CaCo3 + HCL --> CaCl2 + H2Co3 or something. Clearly i dont remember/understand the rule. Can someone regurgitate the rule for me again? ( or specify which dotpoint in the syllabus this was in if you arent bothered to) Thank you!

Regarding your first question -- it's not quite as simple as that. In order to fully understand why that OH group is not acidic really comes down to a concept of resonance, electron distribution, electron orbitals, pKa and conjugates.

For now, with what the HSC gives us, you just need to accept it.

 

[Snowflek]

Regarding your first question -- it's not quite as simple as that. In order to fully understand why that OH group is not acidic really comes down to a concept of resonance, electron distribution, electron orbitals, pKa and conjugates.

For now, with what the HSC gives us, you just need to accept it.

Oh because in one of the questions my teacher gave me, the answers she provided us said what i said.

 

[Fizzy_Cyst]

Oh because in one of the questions my teacher gave me, the answers she provided us said what i said.

What exactly did it say?

All you really need to know is that Citric acid is triprotic due to the 3 carboxyl functional groups, forget about the other OH group as the reasoning behind why that is not acidic is beyond HSC

 

[Snowflek]

What exactly did it say?

All you really need to know is that Citric acid is triprotic due to the 3 carboxyl functional groups, forget about the other OH group as the reasoning behind why that is not acidic is beyond HSC

Question : “According to the Lowry-Brönsted theory of acids, all acids contain hydrogen atoms.
However, there are many compounds which contain hydrogen atoms which are not
classified as acids.”

Use the following examples to assess this statement.
· ethylene, C2H4
· methanoic acid, HCOOH
· hydrogen bromide, HBr (g)

Answer for methanoic acid:Methanoic acid has 1 hydrogen atom (that bonded directly to the carbon atom) which
is not acidic, because this bond is non-polar, as in ethylene. However, the O-H bond
in methanoic acid (part of the -COOH carboxylic acid functional group) is polar, with
the electrons in the bond attracted to the very electronegative oxygen atom. This
hydrogen atom can be lost as a proton, so methanoic acid is classified as a monoprotic
acid, in that it can lose 1 of its 2 hydrogens.