Describe how to make 100 mL of a 0.120 M solution of CU(NO3)2 * 3H20

(Making a solution lab)

1 answer

How many mols do you want? That's M x L = ?
Then mols = grams/molar mass. You know mols and molar mass; solve for grams.
What you want to do is weigh out that amount of Cu(NO3)2.3H2O, place it in a 100 mL volumetric flask, add some water, swirl to dissolve all of the salt, then make up to the mark on the flask with DI H2O, and mix thoroughly. The mistake many students make is to say to add the salt to 100 mL H2O and if you do that it will be wrong. salt + 100 mL makes MORE than 100 mL volume.