Chemistry WS 9-3 Dilutions Worksheet
Name:____________________________
Period: _____
McVc = MdVd
where :
Mc = molarity of concentrated stock sol’n
Md = molarity of the diluted sol’n
Vc = Volume of the concentrated stock sol’n
Vd = volume of the diluted sol’n
1. When a concentrated stock solution is diluted to prepare a less concentrated reagent, the
number of _______________ is the same before and after dilution.
2. When the volume of a given solution is doubled by adding water the new concentration is
_______________ the original concentration.
3. Calculate the new molarity that results when 250.0mL of water is added to each of the
following solutions (add the volume of water to the existing volume and divide moles by
the new volume):
A. 125mL of .251M HCl (0.084M)
B. 445 mL of 0.499M H2SO4 (0.320M)
C. 5.25 mL of 0.101M HNO3 (0.0021M)
D. 11.2 mL of 14.5M HC2H3O2 (0.62M)
4. Concentrated sulfuric acid is typically 18.1M H2SO4. Calculate the volume in mL of
concentrated sulfuric acid needed to prepare 125mL of 0.100M H2SO4 solution. (0.691mL
of 18.1M H2SO4)
5. If you add 25 mL of water to 125 mL of a 0.15 M NaOH solution, what will the molarity of
the diluted solution be? (0.125)
6. If you add water to 100 mL of a 0.15 M NaOH solution until the final volume is 150 mL, what
will the molarity of the diluted solution be? (0.100)
7. How much 0.05 M HCl solution can be made by diluting 250 mL of 10 M HCl? (50,0000)
8. I have 345 mL of a 1.5 M NaCl solution. If I boil the water until the volume of the solution is
250 mL, what will the molarity of the solution be? (2.07)
9. How much water would I need to add to 500 mL of a 2.4 M KCl solution to make a 1.0 M
solution? (700)