need help working out a chemistry problem

Question

What is the new mass/volume (m/v)% of a KOH solution that is prepared by diluting 110 mL of a 6% (m/v) KOH solution to 330 mL?

 

A) 2% B) 1% C) 6% D) 12% E) 18%

Answer 1

This is a dilution problem. When you make dilute solutions from a stock solution, a useful formula is:

M₁V₁=M₂V₂

Where M₁V₁ are the concentration and volume of the stock solution respectively and M₂V₂ are the concentration and volume of the dilute solution respectively.

 

M₁= 6% (m/v)               M₂= unknown

V₁=110 mL                      V₂ =330 mL

 

Make M₂ the subject of the formula:

 

M₂= (M₁V₁)/V₂ =(6%(m/v) ×110 mL)/330 mL = 2% (m/v).

 

Your answer choice is A (2% (m/V).