Identifying Salts

Most recent answer: 10/22/2007

Q:
If you are given three salts in water solutions how would i find out what each one is?
- Andrew Wulf (age 9)
Sheridan, Wyoming, USA
A:
Hi Andrew- There are all sorts of different things that can be done, depending on what equipment is available.
If you happen to have an atomic absorption spectrometer, you can vaporize the solution and see which atoms are in it by seeing what frequencies of light the vapor absorbs. Different atoms absorb diferent frequencies.
If (less likely) you have access to a mass spectrometer, you can directly measure the masses of the atoms, basically by applying known forces to isolated atoms in a vapor, and measuring the accelerations.

If you have access to an instrument like a pH meter but with electrodes sensitive to specific ions, you can use that to measure the presence of those ions directly in the solution itself.

There are a variety of different chemical techniques, seeing what reacts with the ions, if you have the right chemicals to use in those reactions.

You might be able to dry out the solution and tell by the visual appearance of the crystals, especially if you have standard solutions with known salts for comparison.

I would not use taste to identify salts, since some are poisonous. The ion-sensitive electrodes do pretty much the same thing as your taste sensors.

Mike W.

(published on 10/22/2007)