To confirm the presence of sodium or potassium ions, it is neccessary to use the flame test...?

Question

Why is it not possible to precipitate these ions by reactions similiar to those used to identity barium, silver, etc.? (adding (NH4)2CO3 to barium makes a precipitate and adding HCl to silver makes it precipitate)...

Answer 1

This is because the salts of alkali metals are mostly water soluble.

See here:

http://dbhs.wvusd.k12.ca.us/webdocs/Equa...

Answer 2

Because almost all salts of sodium and potassium are very water soluble. They form no precipitates.