what is the maximum amount of KNO3 that can dissolve in 300 grams of water at 40 degree C. Solubility of KNO3 is 60g/100g at 40C.

Question

how do i start to solve this?

Answer 1

If that is 60 g KNO3 per 100 g H2O, then
60 x (300/100) = ? g in 300.

Answer 2

so 180 g of KNO3?

Answer 3

Yes, unless the solubility figure is quote another way than what I listed.
60 g KNO3/100 g H2O is not the same as 60 g KNO3/100 g solution.