posted by jenny .
4. Compound B is provided as a solution and has a specific gravity of 0.65 (Specific gravity is the weight in grams per mL of solution) and is known to be 90% pure (each gram of compound B solution only contains 90% Compound B and 10% of degradation products). 4.5 mL of Compound B is diluted with 55.5mL of water. What is the concentration of this solution?
Specific gravity 0.65 is
0.65 g/mL. How much will 1000 mL weigh. It will be 0.65 g/mL x 1000 = 650 g.
How much of that is compound B? only 90%; therefore, 650 x 0.90 = 585 g B/L soln.
Then you take 4.5 mL and dilute with 55.5, which IF you assume 4.5mL + 55.5 = 60 mL (it may not be that volume you know) so the solution is now 585 g/L x (4.5/60) = ? g/L