Question

What is the final concentration (M) of a solution prepared by diluting 50.0 mL of a 6.00 M KCl solution to a volume of 0.500 L?


A. 1.67
B. 0.600
C. 0.0167
D. 3.0
E. none of these

My initial thought was to take the 6.00 M KCl/0.500 L, for an answer of 12. This baffles me that the only answer suitable would be E. None of the above--I think I did something wrong.

Word of advice!!! Never take a Chemistry class online!!!

Answer 1

You are diluting 6.00 M solution from 50 to 500 mL; therefore, the final concn is
6.00 x (50/500) = 0.600 M

There is another, more fundamental way of doing this.
1. How many moles do you have in the 6.00 M solution. moles = M x L = 6.00 x 0.05 L = 0.300 moles.

2. How many moles do you have in the diluted solution? Of course, 0.300 moles.

3. What is the concn? The definition, remember, is M = moles/L; therefore, M = 0.300 moles/0.5 L = 0.600 M.

Answer 2

its 0.600