試題詳解

1. If a certain volume of potassium hydroxide solution with a solute mass percentage of 14% is evaporated to remove 50 g of water, the solute mass fraction becomes 28% and the volume of the solution becomes 62.5 mL. What is the concentration of the substance in the concentrated solution?
(A)2.20 M
(B)3.00 M
(C)4.00 M
(D)5.00 M
(E)6.25 M