Question

Explain in detail how to prepate the following solution including masses, and or volumes of materials and a sentance or two describing how you would actually prepare the solution, include what types of glassware or other equipment you would use..

a.) 250.0 mL of a solution which is 250. ppm in sodium, starting from solid sodium phosphate Na₃PO₄ a soluble salt

Answer 1

The Glassware required will be 250 ml standard flask, the common balance, weighing box, salt container, funnel and water bottle

required concentration =250ppm

volume of solution= 250ml=250gms = 0.25 kg(since density of water is 1gm/ml)

mass of solute to be weighed(in mg)=ppmXmass of solution in kg=250 X0.25 = 62.5 mg or 0.0625gm

Calibrate the weighing machine and take the weight of empty salt container . now weigh about 62.5mg of sodium phosphate salt and transfer it to the standard flask using funnel. again measure the empty salt container to identify the exact amount of salt tranferred.Add a little bit of water and disolve the salt in it once the salt is soluble make the solution upto the mark using the water check for the lower miniscus of the solution to touch the mark on standard flask now shake the solution thouroughly to get uniform concentraion of solution.