Question #8b34f

1 Answer
May 21, 2016

About #"32 g/100 g H"_2"O"#

Explanation:

Potassium nitrate, #"KNO"_3#, has a solubility of about #"32 g"# per #"100 g"# of water at #20^@"C"#.

You can see this by examining potassium nitrate's solubility curve, which looks like this

http://www.sciencequiz.net/jcscience/jcchemistry/water_solutions/water_solutions_mcq.htm

As you can see, you can dissolve #32-"33 g"# of potassium nitrate per #"100 g"# of water at this temperature.

In other words, dissolving that much potassium nitrate in #"100 g"# of water at #20^@"C"# will produce a saturated solution, i.e. a solution in which you can no longer dissolve any solid.

Any excess of potassium nitrate added over the solubility of the salt will remain undissolved.

Notice that as temperature increases, the solubility of the salt increases as well.