Answer to Question #142915 in General Chemistry for Kelechi Agbi

Question

Dilutions/Titers:
25. Calculate the dilution factor for the following problem: 10 mL sample added to 190 mL diluents
26. What is the final dilution of an unknown blood specimen using 0.1 mL blood with 3.4 mL of water and 1.5 mL of reagents?
27. If 20 mL of saline is added to 4 mL of serum, what is the serum dilution?
28. A urine sample has a concentration of 500 mg/dL. A dilution series is then carried out with the following dilutions for each tube: 1⁄2, 1⁄2, 1⁄2, 1⁄2 and 1⁄2.
a. Find the concentration in each test tube.
b. Give the final concentration for the sample.

Answer 1

25. Total volume = 200 ml

10 : 200 = 1 : 20

20 – dilution factor

26. Total volume = 0.1 ml + 3.4 ml + 1.5 ml = 5 ml

0.1 : 5 = 1 : 50

An unknown blood specimen was diluted 50 times.

27. Total volume = 20 ml + 4 ml = 24 ml

4 : 24 = 1 : 6

The serum was diluted 6 times

28. a. 250 mg/mL, 125 mg/mL, 62.5 mg/mL, 31.25 mg/ml, and 15.625 mg/mL

b. 15.625 mg/mL