Why is Peracetic acid more acidic than Acetic acid?

Question

peracetic acid: HC2H3O3

acetic acid: HC2H3O2

please be descriptive and explain throughly.
Thank you

Answer 1

If you're not a chemistry student: The place on the molecule which makes both acetic acid and peracetic acid acidic is the hydrogen atom bound to the oxegen molecule (only one place in either chemical). Lots of chemicals have hydrogen atoms bound to oxygen atoms that are not acidic (like water, and alcohol). What makes these two different chemicals acidic is the oxygen that is double bound to the adjacent carbon atom, this is called a caboxy group. The hydrogen atom bound to the oxygen atom shares some electrons with the oxygen atom, this is their bond. If the hydrogen atom left the molecule it would leave alot of electrons (well just 2) with out a place to go, but a carboxy group can share the burden of free electrons and stabilise the molecule (The electrons float between the two oxygen atoms in the acids). Chemicals like alcohol do not have adjacent carboxy groups to stabilise free electrons, so these molecules cannot readily lose their hydrogen atoms (losing hydrogen atoms is the definition of an acid). Peracetic acid has and extra oxygen atom to help share the burden of the free electrons even more! The more a chemical can stabilise after the lose of a hydrogen atom, the more acidic it is.
For a chem student: The displaced electrons from the loss of a proton are more stabilised by the addition of the extra oxygen atom.

Answer 2

the major cause is that peracetic acid is more electronegative than acetic acid.

How Made:
Peracetic acid (PAA) is produced by reacting acetic acid and hydrogen peroxide. The reaction is allowed to continue for
up to ten days in order to achieve high yields of product according to the following equation.

O O
|| ||
CH3-C-OH + H2O2 CH3C-O-OH + H2O

sour smell and is included in the chemical group of hydroperoxides. It is highly oxidant and corrosive and can explode at temperatures exceeding 110ºC. It is more fat-soluble than hydrogen peroxide.

Peracetic acid is produced by oxidation of acetaldehyde or by letting acetic acid react with hydrogen peroxide in the presence of a sulphuric acid catalyst. Peracetic acid is sold as a 40% solution in acetic acid. The mixture has to be stabilised with dipicoline acid, phytic acid or phosphates and a little hydrogen peroxide, to prevent the peracetic acid disintegrating too rapidly.

As a synthesis chemical, peracetic acid is used to add an oxygen atom to double bonds, e.g. in ethene and propene. In this way epoxides and alcohols can be formed and peracetic acid is used for production of synthetic glycerol (from propene). It is also used in nylon manufacturing.

Peracetic acid can be used as a bleaching agent and for disinfection. Since it emits oxygen more readily and at lower temperatures than other bleaching agents, it is gentle on the material to be bleached or disinfected. It is broadly effective against micro organisms and is not deactivated by catalase and peroxidase, the enzymes which break down hydrogen peroxide. Peracetic acid is used especially in facilities for industrial handling of foodstuffs, because it acts at low temperature and low pH and the degradation product, acetic acid, seldom needs to be rinsed away.

http://www.apps.kemi.se/flodessok/floden/kemamne_eng/gif/perattiksyra.gif

Delignification and bleaching of lignocellulosic material is enhanced after the pulp has been treated with peroxomonosulfuric acid. The starting pH of the reaction with peroxomonosulfuric acid is between 7 and 11, and the reaction is continued until a final pH of 3 to 5 obtained. Subsequently the pulp is delignified and bleached with peroxide and/or oxygen.