Help With Esters - (Basic Knowledge!)

[kjf]

Hey everyone,

I just joined this forum, and I'm after a bit of help

 

Okay, so I recently took part in a chem prac at school, and I'm doing the right up. There's a question I need to answer, and I can't find much info on it!

 

So yeah, to the question:

 

"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?)"

 

I really don't know, and it's eating away at me!

 

So, any help would be appreciated.

 

Regrards,

 

kjf

[CaptainPanic]

Perhaps it would be useful to tell us what else was in the test tube?

 

You mention esters in your title. Esters have a strong smell, and are found in many types of food (fruits, and also synthetic stuff). Esters may dissolve in the water, so perhaps esters were present in the water.

 

But with the limited information in your question, it is hard to give a good answer.

[YT2095]

it`s crashed into water quite simply because esters tend not to be water soluble and will float whereas the acid catalyst and the 2 ester precursors tend to be water soluble.

so when you crash it into water you get a better idea of the true Smell of the ester, and the all the rest is Under this layer.

[kjf]

Ah, sorry I didn't give you enough information.

I wrote the answer before you guys replied, and this is what I came up with:

 

Distilled water was added to the test tube before smelling due to two reasons – to dissolve the leftover acid and alkanol, and to make the ester form a layer on top of the substance. When regarding solubility, esters with a low number of carbons (generally four or less) are considered to be moderately soluble. As the number of carbon atoms increases, the solubility of that certain ester decreases.

 

The soluble esters, usually with five or more carbons in a straight chain, tend to form a thin layer on the surface when water is added once the reaction has taken place. The excess acid and alkanol (the reactants) both dissolve in the added water because they are both soluble in water, and were tucked safely away under the layer of ester which formed. The water was added so this layer was formed, thus making the ester form a layer on top which in-turn intensifies the smell of the ester produced.

 

I appreciate the replies though!

 

I really like this forum.