# Dilutions

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7-1. 1:2, first, then 1:3, the 1:8, for a total dilution factor of 1:2*3*8 or 1:48

7-2. 4:10, or 1:2.5 at first. An additional 1:10 will make the final dilution factor 1:25

7-3. 1:6 initial dilution for tube 1. Five more 1:2 dilutions are made, making the final dilution factor 1:6*2*2*2*2*2, or 1:192!

7-4. This is 6 1:3 serial dilutions, 1:3^6, for a final dilution of 1:729

7-5. Add 3 mL of water to each tube, and then make the initial dilution by adding 1 mL of stock. Take 1mL of the first dilution and add to the second tube, repeating until you reach the final tube, assuming we want a 1:4 dilution with each tube.

7-6. Add 0.5 mL of water to each tube. Perform the same procedure as in 7-5, except add 0.5 mL of the previous or stock solution

7-7. This is 1:10, so 10mg/dL

7-8. 1:6, then 1:4. Total dilution=1:24, so 1000/24= 41.7mg/dL

7-9. 2.0g/dL is 2000mg/dL, so we need a total 1:40 dilution factor. If we wanted 1L, then we would take ...

#### Solution Summary

15 dilution problems are included in this solution as well as 19 other problems related to concentrations. This is a valuable solution set which specifically deals with these concepts:

1) Calculating the dilution factor of serial dilutions

2) How to perform and calculate serial dilutions

3) Conversions of metric units (ng to mg, for example)

4) How to prepare solutions of varying molarity, normality, and %

5) The difference between %w/w and %v/v are explored briefly

6) How to change molarity to normality.