[KJF]

I'm about to do a Chemistry Prac at school (ahm..actually tommorow)

We're creating esters from carboxylic acids, and there are a few questions on the prac sheet that I don't understand.


1. 'Why were the reactions kept free of water during heating?'

2. 'Why was water added to the tube before you were asked to smell it? (Hint: What was in the water layer in the test tube?). Discuss the relative solubility of acids, alcohols and esters in water in order to answer this question.'


We havn't done much (about a quater of a lesson) on esters, so I'm a bit of a novice.

If anyone can help, or give me some more info about this topic, it would be greatly appreciated!

Thanks,

Karl

[sjb]

How much is "a quarter of a lesson" - some lessons last all day, others less than 30 minutes in my experience.

However a few thoughts on 1)

Depending on how you made your ester, it could either be an equibilbrium between alcohol and acid, and ester and water.

In one form, Le Chatelier's Principle states that if you remove products from an equilibrium the equibilibrum is shifted towards products.

Another way to make esters is alcohol and acid chloride to ester. This way is less reversible, but the acid chloride reacts with water to give back the acid, which could give you issues as per the first point.

As to part 2. Are alcohols, acids soluble in water? What about esters? What is the "mechanism" for being able to smell things?