Question

What is the solubility of `NH_3` in 100 g of water at a temperature of 20°C?

Answer 1

Large.

Explanation:

The commercial product ammonium hydroxide (or more correctly saturated aqueous ammonia), is approx, `30%` ammonia by mass.

If you have the density available, you can solve for the aqueous concentration, and you get approx. `15*mol*L^-1`. Note that here I careful to distinguish between aqueous ammonia, a solution of ammonia in water, with liquid or gaseous ammonia, a colourless gas at room temperature, that is very soluble in water.

Look at videos of the ammonia fountain on the web; there should be some good ones. I would post one here, but my google fu is weak, and I would not attribute it correctly.