phagocytes

There is a procedure for hydrolysis of amides by dissolving them in sulphuric acid then poring the solution into water. I've never tried it but it should make the acid directly.

http://aycu10.webshots.com/image/29969/2004225986637034140_rs.jpg

Yes, after boiling with NaOH ,suction filtration is then carried out ,then excess HCl is added to the yellow ppt. .Finally the mixture is dissolved in HOT water(recrystallization).Then the solid obtained is Needle-like .

I would like to ask if the yellow ppt. is sodium benzoate and why the benzoic acid is Needle-like .By the way ,will there any side product be formed ?

I think the reason of carring out alkaline hydrolysis is to shift the equilbrium to the right in order to obtain more crystals since NH3 can be esaily removed, but i am not sure if i am right.

The benzoic acid is prepared by alkaline hydrolysis of benzamide

I would like to ask why the shape of benzoic acid obtained is Needle-like and why there is yellow ppt. after boiling benzamide with NaOH for about 15 minutes?

Thanks

NO NO NO!

 

Methyl Benzoate is a benzene ring with a carboxylic acid group attached. http://en.wikipedia.org/wiki/Methyl_benzoate

 

And thus, you have to consider the withdrawing affects when nitrating.

 

http://www.mhhe.com/physsci/chemistry/carey/student/olc/graphics/carey04oc/ref/ch12substituenteffects.html

 

Since the COOH group is meta directing, there is only one carbon in which the NO2 group will be added.

 

the mechanism will look like this:

 

i see

Thanks!

Thanks a lot!

How do the conditions for nitration of methyl benzoate differ from those for the nitration of benzene?

what is the mechanism nitration of methyl benzoate to form methyl 3-nitrobenzoate?

Thanks.

How do the conditions for nitration of methyl benzoate differ from those for the nitration of benzene?

what is the mechanism nitration of methyl benzoate to form methyl 3-nitrobenzoate?

Thanks.

Is sodium thiosulphate easily oxidized by oxygen

I guess he wants to know why, unlike most indicators, starch is added near the end of the titration. The fact that this is true for thousands of titrations doesn't really matter.

 

Anyway there are several reasons.

Starch is a reducing agent (especially if it hydrolyses to glucose) so you don't want to add it too soon or it may react with the oxidant and upset the result.

More importantly when the starch reacts with a large excess of iodine it tends to "trap" some of the iodine so, even after enough thiosulphate has been addded, the mixture stays blue for a while and you tend to add too much thiosulphate. This spoils the accuracy of the titration.

thanks

Determination of the activation energy for the Iodination of Propanone

by finging the rate constant at different temperature

"Add starch just before titration end"WHY?