posted by Jessica on .
Determine the number of grams of water which are required to dissolve a mixture of 25 g of KNO3 and 2.0 g of CuSo4 * 5H20 AT 100 Degrees celscius?
We need the solubility numbers for KNO3 and CuSO4.5H2O. YOu must have them in a table, either in your text, notes, or in the problem. (Note the correct spelling of celsius.)
So, the soulubility for Kno3 IS 245 of 100 grams in water. The solubility for CuSo4 is 180 grams over 100 grams of water. How would you solve that?
Is that the solubility at 100 C? I assume it is. Then KNO3 will require
100g H2O x (25/245) = about 10 g H2O (but you need to do it more accurately).
CuSO4.5H2O will require
100 g x (2/180) = about 1 gram H2O.
Generally, one does not add the masses of the water. Generally, the more soluble salt (in this case KNO3) will take about 10 g H2O to dissolve it AND the solution will have enough room to dissolve the smaller amount of CuSO4.5H2O also.