Page 28 - E-LKM ACID BASE

Lembar Kerja Mahasiswa - Asam Basa

C. The effect of solvent on the strength of acid and

In acid-base chemistry the solvent used is not limited to
water. There are many other solvents used such as liquid

ammonia and glacial acetic acid. Glacial acetic acid is nearly
pure acetic acid. It contains less than 1% water.

You have studied that in water ammonia is a weak base,

whereas acetic acid is a weak acid.

Based on equations above, we can conclude that the
strength to donate proton of CH COOH>H O>NH or the strength
3
2
3
to accept proton of CH COOH<H O<NH If we replace water with
2
3
3
ammonia in equation above we will get the following equation.

Since NH is a stronger proton donor than H O, in NH solvent,
2
CH COOH is more easily to donate its proton. Therefore the
3
strength of CH COOH increase in NH solvent. Since NH is a
3
3
3
stronger acid than H O or NH is more basic than H O, the
2
3
2
strength of CH COOH, increases in a solvent which is more
3
acidic than water. In general, the strength of acid increases in
basic solvent. NH is weak base in water. If we were replace
3
water with glacial acetic in equation, we will get the following
equation.

(Effendy, 2011)

Bahasa Inggris Kimia (PKIM3139) 24