A solution contains 35 grams of #KNO_3# dissolved in 100 grams of water at 40°C. How much more #KNO_3# would have to be added to make it a saturated solution?
Your tool of choice here will be the solubility graph for potassium nitrate,
As you can see, potassium nitrate has s solubility of about
You know that at this temperature, your solution contains
In order to make a saturated solution, you must get the total mass of potassium nitrate to
#"mass of KNO"_3 color(white)(a)"to be added" = "67 g" - "35 g" = color(green)(|bar(ul(color(white)(a/a)color(black)("32 g")color(white)(a/a)|)))#
So, dissolving another