Can somebody explain?

[td4azklz]

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Appearing in the form of +H3NCH2CO2H, this polyprotic acid requires 2 equivalents of base to be completely neutralized with.

Could somebody please explain why you would need 2eqv of base? Thanks.

 

[PooyaH]

Well this is referring to normality. Let's say if you have a diprotic acid you need 2 equiv. NaOH since there are 2 H+. Here you have 2 acidic hydrogens: one on the carboxylic acid and one on the NH3+ (which I think it should be NH4+) So you need 2 bases to react with it and neutralize it!

 

[td4azklz]

Well this is referring to normality. Let's say if you have a diprotic acid you need 2 equiv. NaOH since there are 2 H+. Here you have 2 acidic hydrogens: one on the carboxylic acid and one on the NH3+ (which I think it should be NH4+) So you need 2 bases to react with it and neutralize it!

That's what i thought too, but the explanation in DAT achiever said you need 2 eqv of base to neutralize +H3NCH2CO2H. So i dont know 🙁

 

[PooyaH]

That's what i thought too, but the explanation in DAT achiever said you need 2 eqv of base to neutralize +H3NCH2CO2H. So i dont know 🙁

Oh you know what that is correct!!! I never thought about the carbon attached to the Nitrogen! So that is correct CN3H+....I forgot about the carbon!

 

[shoombol tallah]

see thats what happens when pooya helps you, gives the wrong damn answer !! LOL

 

[PooyaH]

see thats what happens when pooya helps you, gives the wrong damn answer !! LOL

hey shut your mouth! lol

 

[td4azklz]

hey shut your mouth! lol

haha....

So ok, can you explain again please? Please??

 

[td4azklz]

haha....

So ok, can you explain again please? Please??

What about the carbon that's attached to the nitrogen?

 

[PooyaH]

What about the carbon that's attached to the nitrogen?

Nitrogen can make 3 bonds to other atoms. So if it makes four bonds it no longer has any basic property because it gains a positive charge. Just think about NH3 which is basic, but NH4+ is acidic!

Here you have CNH3+ which is acidic because Nitrogen is making four bonds with other atoms. If if was CNH2, it wouldn't have been acidic!

 

[td4azklz]

Ok, i get the CNH3+ part, that gives us an eqv of 1 base, where is the other? Since we only have one charge (+), how would 2 eqv. make this neutral? I'm sorry, I am just having a slow day today...

 

[PooyaH]

Ok, i get the CNH3+ part, that gives us an eqv of 1 base, where is the other? Since we only have one charge (+), how would 2 eqv. make this neutral? I'm sorry, I am just having a slow day today...

The other one is one the carboxylix acid!

+H3NCH2CO2H

 

[rdhdds1]

Gotcha on this one. The best thing to do in these types of questions is break out what you have in the substance then attack the question.

COOH and NH3C

Pooya did a great job explaining.😎

 

[doc3232]

Someone already asked this question before.

 

[td4azklz]

Thanks everyone! I finally get it now...i promise 😀

 

[rendezvousing]

yeah, this confused me too,

so we need 2 equ base to neutralize one on the nitrogen hydrogen and one on the carboxylic acid hydrogen?

is that right?
Thanks

 

[td4azklz]

yeah, this confused me too,

so we need 2 equ base to neutralize one on the nitrogen hydrogen and one on the carboxylic acid hydrogen?

is that right?
Thanks

Yes, thats correct. One base for each hydrogen

 

[doc toothache]

Glycine is an amphoteric compound, which reacts with hydrochloric acid to form glycine hydrochloride, a quarternary ammonium compound (salt), which is acidic. One equivalent of NaOH is required to obtain the free base and another equivalent is required for the -COOH group, which is converted to the sodium salt.

 

[rdhdds1]

Yes, thats correct. One base for each hydrogen

Because they are acidic.....................