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1. In the laboratory you dilute 5.39 mL of a concentrated 6.00 M hydrochloric ac

ID: 890422 • Letter: 1

Question

1. In the laboratory you dilute 5.39 mL of a concentrated 6.00 M hydrochloric acid solution to a total volume of 50.0 mL. What is the concentration of the dilute solution? _____________ M

2. In the laboratory you dilute 4.09 mL of a concentrated 6.00 M perchloric acid solution to a total volume of 100 mL. What is the concentration of the dilute solution? _____________ M

3. In the laboratory a student combines 30.8 mL of a 0.322 M chromium(II) bromide solution with 14.9 mL of a 0.474 M chromium(II) acetate solution.

What is the final concentration of chromium(II) cation ? ____________ M

Explanation / Answer

1) The resultant molarity = (5.39 mL)(6.00 M) / 50 mL = 0.65 M

2) The resultant molarity = (4.09 mL)(6.00 M) / 100 mL = 0.25 M

3) Total mols of Cr2+ = [ (30.8 mL)(0.322 M) + (14.9 mL)(0.474 M) ] / (14.9 mL+30.8 mL)

                                  = 0.371 M