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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Arnold on February 18, 2007, 08:36:08 AM

Title: [Solved]Why not these other norm carboxylic acid and alcohols don't react ...
Post by: Arnold on February 18, 2007, 08:36:08 AM
Hi.

Carboxylic acids react with sodium right?

In its reaction with sodium,1 mol of a compound X gives 1 mol of H2(g)
Which compound might X be?
A.CH3CH2CH2CH2OH
B.(CH3)3COH
C.CH3CH2CH2COOH
D.CH3CH(OH)COOH (Correct answer)

As u can see,why those two alcohols-A & B and that carboxylic acid-C isn't the answer,pls tell?
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Borek on February 18, 2007, 09:42:43 AM
Which protons do react with sodium? All of them, or only some?
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Arnold on February 18, 2007, 11:04:36 AM
No proton react,but the O atom reacts with the Na+ which replaces the H+.How?
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Borek on February 18, 2007, 12:10:41 PM
OK, let me reword my question. WHICH protons can be replaced by Na - all of them, or only some?

Note, that you have already gave the information needed. You just have to put it all together :)
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Arnold on February 18, 2007, 07:32:03 PM
Hi.

Carboxylic acids react with sodium right?

In its reaction with sodium,1 mol of a compound X gives 1 mol of H2(g)
Which compound might X be?
A.CH3CH2CH2CH2OH
B.(CH3)3COH
C.CH3CH2CH2COOH
D.CH3CH(OH)COOH (Correct answer)

As u can see,why those two alcohols-A & B and that carboxylic acid-C isn't the answer,pls tell?

Well Borek,I think the protons listed below reacts-

For A-the alcohol group's proton

"    B-the alcohol group's proton

For C-the carboxylic acid group's proton

For D-Any of the alcohol group's proton or carboxylic group's proton.


From what I c,all can react with Na,ie all is correct.But why the answer happen to be D?
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Borek on February 19, 2007, 02:45:09 AM
OK, abc have 1 proton that can react, d has 2 such protons. Think stoichiometry. Try to write reaction equations.
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Arnold on February 19, 2007, 06:03:52 AM
Ok.
For:
A. CH3CH2CH2CH2OH + Na -> CH3CH2CH2CH2ONa + 1/2 x H2(g)
B. (CH3)3COH + Na -> (CH3)3CONa + 1/2 x H2(g)
C. CH3CH2CH2COOH + Na -> CH3CH2CH2COONa + 1/2 x H2(g)
D.1st way: CH3CH(OH)COOH + Na -> CH3CHONaCOOH + 1/2 x H2(g)
   2nd way: CH3CH(OH)COOH + Na -> CH3CH(OH)COONa + 1/2 x H2(g)

There it is.Well basicly I still haven't got the ans I 1 & they're all correct,how?
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Borek on February 19, 2007, 06:29:27 AM
D.1st way: CH3CH(OH)COOH + Na -> CH3CHNaCOOH + 1/2 x H2(g)
   2nd way: CH3CH(OH)COOH + Na -> CH3CH(OH)COONa + 1/2 x H2(g)

Why not BOTH ways at the same time?
Title: Re: Why not these other norm carboxylic acid and alcohols don't react with sodium?
Post by: Arnold on February 19, 2007, 06:56:42 AM
Both ways,yeah of course they do.
CH3CH(OH)COOH + 2Na -> CH3CHONaCOONa + H2(g)

Thanks indeed Boreks for the idea of above ^,you've been helpful.Bye.