Answer to Question #155382 in General Chemistry for Snowy Morudu

Question

     What volume of a 1:4 solution of thorazine is needed to prepare 250.00 mL stock solution,

           such that if 10.00 mL of this solution is made up to 500.0 mL with purified water, a thorazine

             solution with a concentration of 0.400% would result?  

Answer 1

w = m(thorazine) / m(solution)

0.004 = m / 500

m = 0.004 x 500 = 2 g

2 g - 10 ml solution

x g - 250 ml solution

x = 2 x 250 / 10 = 50 g thorazine

50 ml of 1 : 4 solution