posted by Bob .
6. Compound C (MW = 550) is provided at a concentration of 25g/100mL. 1mL is taken and compound D is to be added (MW = 1025, concentration = 75mM) to give a final ratio of compound C:D of 4:1 moles ratio. What volume of compound D is to be added?
I expect you will never get this answered, at least on this board, until you have determined what kind of ratio you want. Is that 4:1 by grams or by moles?.
25g C/550 = estimated 0.05 and that dissolved in 100 mL = 0.05/0.1 = about 0.5M.
You take 1 mL of that so you have
0.5 x 0.001L = 5E-4 and that times 4 = about 20E-4.
Then 20E-4/0.075M for D = ?L and convert to mL.