Vinegar – acetic acid

What does it look like?

Image generated by the VESTA (Visualisation for Electronic and STructual analysis) software http://jp-minerals.org/vesta/en/

Image generated by the VESTA (Visualisation for Electronic and STructual analysis) software http://jp-minerals.org/vesta/en/

What is it?

170px-AceticAcid012This is the molecule that gives the tang on your tongue when you add vinegar to your chips. Most vinegars have about 4-5 % acetic acid molecules in the mix. In pure form, acetic acid is known as ‘glacial’ acetic acid because of the snow-like white crystals it grows.

The image we’ve shown would seem a very over-simplified image of the crystal structure as it is missing the all-important four hydrogen atoms. However, as we’ve mentioned on the blog a few times before, finding hydrogen position from x-ray diffraction is extremely challenging as they don’t scatter very well. It would take a later neutron diffraction study to place when the hydrogen positions are in this material.

Where did the structure come from?

This arrangement of molecules came from a paper by Jones and Templeton, published in 1958. This is a very early determination of a molecular crystal structure, and the work built on information from other experimental methods, including spectroscopy.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s