What are the reagents in an iodoform reaction

[lioric]

Homework Statement

this question is about the organic reactions shown in the diagram. ( diagram shows that butan2one is reaction with a reagent P and Q and then reagent R and forms propanoic acid and iodoform)

a)name the reagents P and Q used in reaction 1.
b) identify the reagent R used in reaction 1 and explain why it is needed

Homework Equations

I do know that for iodoform reaction you need sodium hydroxide in iodine solution
But I'm wondering what the Reagent R is

The Attempt at a Solution

 

[TeethWhitener]

I do know that for iodoform reaction you need sodium hydroxide in iodine solution

What are the products you get if you just put in sodium hydroxide and iodine in water?
Edit: and of course 2-butanone.

 

[lioric]

What are the products you get if you just put in sodium hydroxide and iodine in water?
Edit: and of course 2-butanone.

NaI and NaOI and water

 

[TeethWhitener]

NaI and NaOI and water

What are the organic products?
Edit: maybe my edit in post 2 wasn’t clear. When you combine 2-butanone, sodium hydroxide, and iodine in water, what are the organic products?

 

[lioric]

What are the organic products?
Edit: maybe my edit in post 2 wasn’t clear. When you combine 2-butanone, sodium hydroxide, and iodine in water, what are the organic products?

Iodoform and sodium propanoate

 

[TeethWhitener]

Iodoform and sodium propanoate

So if you want to end up with propanoic acid, what do you have to do?

 

[lioric]

So if you want to end up with propanoic acid, what do you have to do?

I have seen two versions of this

1) In a haloform reaction with iodine, bromine, or chlorine, methyl ketones are converted into the corresponding carboxylic acid and haloform. (from site chemgapedia
http://www.chemgapedia.de/vsengine/...ik/c_acid/synthese_von_carbonsaeuren.vlu.html

2) the other from McMurry organic chemistry textbook saying that in if we use excess halogen and base than it will form the carboxilic acid
And this link shows it too
https://goo.gl/images/miAQfp

 

[TeethWhitener]

You’re overthinking things. If you have sodium propanoate and you want propanoic acid, what do you need to do?

 

[lioric]

You’re overthinking things. If you have sodium propanoate and you want propanoic acid, what do you need to do?

Add a strong acid like HCl or H2SO4

Salt + acid makes a weaker acid and another salt

 

[TeethWhitener]

Add a strong acid like HCl or H2SO4

Salt + acid makes a weaker acid and another salt

Right. So now just put it all together.