Esterification (1 Viewer)

[lgerrand]

is there a temperature we have to keep the esterification at to create an ester??? what is the best temperature to heat it to???

 

[champo14]

I was going to answer this but then I realised I honestly can't remember.

But TBH I don't think so. I mean, it need to be pretty hot, but I'm pretty sure the reflex does the rest.

 

[brenton1987]

It would depend on what your reactants are and what the products will be. If they all boil over 100^o C you would have the temperature near there so that the water produced can be distilled off pushing equilibrium to produce more product.

If they boil under 100^o C you can not have the temperature too high or your reactants boil away. The reaction yield is affected here.

My organic chemistry textbook says "1-10 hours at 60-110^o C."

 

[Undermyskin]

Yes, it depends on your reactants and their B.P.s. According to Conquering Chem, we should maintain a constant temperature somewhat under the BP of the more volatile one. (lower BP). This is commonly of the alcohol.

However, (tricky) when I did the esterification, I let them boil vehemently (the teacher didn't know) and ended up having the highest yield of ester. Don't bother trying to use waterbath. You know that its heat capacity is 4.18 and basically by the time you reach the temperature you need for the distillation flask, water already consumes most of the heat!

 

[arkyopshop]

mm, and extending on that water bath mention .. most of the time you'll be needing to exceed 100 degrees, so water being water (100 degrees max) it won't work.

re. heat in our chem prac we were told to heat gently until hot, pretty much just be sure you have a steady amount of vapours going through the whole reflux system.

i hope that helps

 

[samwell]

it all depends on many factors. I.e amount of water, type of heating(water bath or direct heatin), Current atmospheric conditions. and e.t.c. But also water generally boils at 100 degrees celcius. Water is usually the least volatile substance in a reflux. There is no exact temperature as it depends on where and when u r performing the experiment. i would guess that 100 degrees is the closest temperature that should be maintained<excludin external factors>

 

[samwell]

.

My organic chemistry textbook says "1-10 hours at 60-110^o C."[/quote]

this is the industrial amount of time. It is quite impossible for an average chemistry lesson in New South Wales

 

[brenton1987]

.

My organic chemistry textbook says "1-10 hours at 60-110^o C."

this is the industrial amount of time. It is quite impossible for an average chemistry lesson in New South Wales

No it isnt.
It is quite safe to leave an esterification reaction unattended overnight. As long as you arent using open flame direct heat, which should never be used with organic chemicals.

 

[Darrow]

Be good, use a heating mantle!

 

[Undermyskin]

What is it? You mean gauze?

 

[Forbidden.]

Too low and the mixture won't undergo esterification.
Too high and the stuff evapourates.
Ethanol has a boiling point of 85^oC

 

[brenton1987]

What is it? You mean gauze?

A heating mantle? No its an electric heater that holds and heats a round bottom flask.
They look like this.

 

[Undermyskin]

Thanks! That's awesome! I don't think my school has that one tho.

 

[aussiechick007]

yeah thats what we used, a heating mantle, and just turned up the heat and hoped for the best lol... well we had it too high at first and the vapours were coming off so turned it down... buyt yeah

 

[Darrow]

aha,
Our school just got one, and our chem teacher (who happens to be the head of science) was all excited.