100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary Topic 8 - Carboxylic acids £2.99   Add to cart

Summary

Summary Topic 8 - Carboxylic acids

 28 views  1 purchase

These are the complete notes for the CCEA A2 1 specification and have been created through multiple sources. However, they are not endorsed by CCEA.

Preview 1 out of 5  pages

  • June 14, 2019
  • 5
  • 2018/2019
  • Summary
All documents for this subject (22)
avatar-seller
JArchy123
Chemistry
Topic 8: Carboxylic Acids

Carboxylic acids R-COOH, contain the functional group -COOH. Aldehydes and Ketones contain the functional
group C=O. Since carboxylic acids also contain C=O and C-O-H you might expect them to have a blend of the
properties of aldehydes, ketones and alcohols, however this is not the case.
 The general formula for carboxylic acids is: CnH2nO2
 Carboxylic acid derivatives include: acyl chlorides R-COCl; esters RCOOR’ and amides RCONHR’

Physical Properties
The physical properties (i.e. boiling point and solubility) of the carboxylic acids and are governed by their
ability to form hydrogen bonds.

Boiling Points
The boiling points of alcohols are higher than those of alkanes of similar size because the alcohols can form
hydrogen bond with each other as well as van der Waals dispersion forces and dipole-dipole interactions.

The boiling points of carboxylic acids of similar size are higher still than their similar sized alcohols
counterparts:
Propan-1-ol CH3CH2CH2OH 97.2oC
Ethanoic acid CH3COOH 118oC

The higher boiling points of the carboxylic acids are still
caused by hydrogen bonding, but this is because in a pure
carboxylic acid, intermolecular hydrogen bonding can occur
between two molecules of acids to produce a dimer.

This immediately doubles the size of the molecules and so
increases the van der Waals dispersion forces between one
of these dimers and its neighbours – resulting in a high
boiling point.

Solubility
In the presence of water, carboxylic acids do not dimerise with
each other. Instead, hydrogen bonds are formed between water
molecules and individual molecules of acid.

The carboxylic acids with up to four carbon atoms will mix with
water in any proportion. When you mix the two together, the
energy is released when the new hydrogen bonds form is much
the same as needed to break the hydrogen bonds in the pure
liquids.

The solubility of the bigger acids decreases very rapidly with size. This is because the longer hydrocarbon ‘tails’
of the molecules get between water molecules and break hydrogen bonds. In this case, these broke hydrogen
bonds are only replaced by much weaker van der Waals dispersion forces.


Summary
 Carboxylic acids have a sharp, irritating odour
 Short chain carboxylic acids are liquids – the polar OH group causes hydrogen bonds between
molecules, which require a lot of energy to break them

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller JArchy123. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £2.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

75759 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now

Start selling
£2.99  1x  sold
  • (0)
  Add to cart