The following shows the beginning of the laboratory preparation of an aqueous solution of the hypothetical compound AB (150.5 g/mol).
-If the volume of the volumetric flask had been 500. mL instead of 100. mL and the amount of AB had been 25.5 g, how would the molarity of the resulting have been affected?
A) increased by a factor of 5
B) reduced by a factor of 5
C) increased by a factor of 10
D) decreased by a factor of 10
E) It would be unchanged.

Question

The following shows the beginning of the laboratory preparation of an aqueous solution of the hypothetical compound AB (150.5 g/mol). 
-If the volume of the volumetric flask had been 500. mL instead of 100. mL and the amount of AB had been 25.5 g, how would the molarity of the resulting have been affected?
A) increased by a factor of 5 
B) reduced by a factor of 5 
C) increased by a factor of 10 
D) decreased by a factor of 10 
E) It would be unchanged.

Quizplus · Accepted Answer

The molarity of a solution is defined as the number of moles of solute per liter of solution. If the volume of the solution is increased, the molarity will decrease. If the amount of solute is increased, the molarity will increase. In this case, the volume of the solution is increased by a factor of 5 and the amount of solute is increased by a factor of 25.5/12.5 = 2.04. Therefore, the molarity of the resulting solution will be unchanged.

The Following Shows the Beginning of the Laboratory Preparation of an Aqueous