Question

Question #71391

Answer 1

No, the solution is not saturated.

Explanation:

Your tool of choice here will be the solubility graph of potassium nitrate, `"KNO"_3`, which looks like this


The curve shows you the amount of potassium nitrate than can be dissolved per `"100 mL"` of water at various temperatures in order to create a saturated solution of potassium nitrate.

For the sake of simplicity, let's assume that the graph shows the solubility of the salt per `"100 g"` of water.

Now, if you draw a vertical line starting from `90^@"C"`, you will notice that it intersects the curve at approximately `"200 g"` of potassium nitrate per `"100 g"` of water.

This represents the solubility of the salt at this temperature. In other words, you can only hope to dissolve `"200 g"` of potassium nitrate for every `"100 g"` of water at `90^@"C"`.

Your solution contains `"30 g"` of potassium nitrate per `"100 g"` of water at this temperature, so it will not be saturated because you can dissolve an additional

`"200 g"color(white)(.) - color(white)(.)"30 g" = "170 g KNO"_3`

for every `"100 g"` of water at this temperature. You can thus say that the solution is unsaturated.