Dilution Chemistry Problem

Question

Problem Page
A chemist makes
910.mL
of calcium bromide
CaBr2
working solution by adding distilled water to
160.mL
of a
5.80
M stock solution of calcium bromide in water.
Calculate the concentration of the chemist's working solution. Round your answer to
3
significant digits.

Answer 1

Hello Mariah

 

This question requires the use of the dilution equation:

 

M_iV_i = M_fV_f

 

The volume and concentration of the "stock" solution will always be the "initial" amounts.  The final volume is 910. mL and the question is asking to solve for the final Molarity (M_f).

 

Substituting the above values in the dilution equation, you get

 

5.80 M x 160. mL = M_f x 910. mL

 

Rearrange and solve for M_f, you get

 

M_f = (5.80 M x 160. mL) / 910. mL  =  1.02 M CaBr₂