Ch 7 Review Questions
14. How much calcium chloride (CaCl2) is needed to prepare 500 mL of a 0.5 M solution of CaCl2? a. 27.7 g b. 40.0 g c. 57.8 g d. 115.6 g
a
15. What is the correct formula for calculating a percent (w/v) solution? a. Grams of solute/Volume of solution × 100 b. Grams of solute × Volume of solvent × 100 c. Volume of solvent/Grams of solute × 100 d. Grams of solute × Volume of solvent/100
a
2. How would 15.57 be rounded off to one less decimal place? a. 15.6 b. 15.5 c. 16.0 d. 15.0
a
23. Concentration is: a. The amount of one substance relative to the amounts of other substances in the solution b. Relative concentrations of the components of a mixture c. The gram-molecular mass (or weight) of a compound per liter of solution d. Expression of one amount relative to another amount
a
3. How would 25.96 be rounded off to one less decimal place? a. 26.0 b. 25.9 c. 25.6 d. 26.96
a
30. You are asked to make a 1:2 dilution using 1.5 mL of serum. How much diluent do you need to use? a. 1.5 mL b. 3.0 mL c. 15 mL d. 30 mL
a
33. If you make a five-tube twofold dilution using 2 mL of serum, what is the concentration of serum in tube #4? a. 0.125 mL b. 0.25 mL c. 1 mL d. 2 mL
a
10. If 6 mL of liquid is placed in a volumetric flask and the volume is brought to 100 mL total, the solution is what percent of liquid? a. 0.6% b. 6% c. 60% d. None of the above
b
12. If there is 25 g of NaCl per liter of solution, what is the molarity? a. 025 M b. 0.43 M c. 0.5 M d. 1.0 M
b
16. If a solution contains 20 g of solute dissolved in 0.5 L of water, what is the percentage of this solution? a. 2% b. 4% c. 6% d. 8%
b
20. What volume of 25% alcohol is needed to prepare 500 mL of 15% alcohol? a. 30 mL b. 300 mL c. 350 mL d. 375 mL
b
24. To dilute a serum specimen 1:10, _____ parts of serum would be added to _____ parts distilled water. a. 1, 10 b. 1, 9 c. 0.5, 4.5 d. Both b and c
b
27. What is the dilution factor if 4 mL of serum is added to 12 mL of diluent? a. 3 b. 4 c. 12 d. 15
b
28. Serum is diluted with an equal amount of diluent (such as tube #1, 1:2 and tube #2, 1:2). What is the concentration in tube #2 if the original concentration was 100 mg/dL? a. 12.5 mg/dL b. 25.0 mg/dL c. 50.0 mg/dL d. 75.0 mg/dL
b
29. If a total of 125 mL of a 10% solution is diluted to 500 mL in a 500-mL volumetric flask, what is the concentration of the resulting new solution? a. 0.25% b. 2.5% c. 25% d. None of the above
b
7. Dilution is: a. The amount of one substance relative to the amounts of other substances in the solution b. Relative concentrations of the components of a mixture c. The gram-molecular mass (or weight) of a compound per liter of solution d. Expression of one amount relative to another amount
b
8. Three grams (3 g) of solute in 100 mL of solvent equals _____% (w/v). a. 0.3 b. 3 c. 30 d. 300
b
9. Twenty grams (20 g) of solute dissolved in 1 L of solvent equals _____% (w/v). a. 0.2 b. 2 c. 20 d. 200
b
11. How many grams of NaCl would be used to prepare 1000 mL of a 5% (w/v) solution of NaCl? a. 0.5 g b. 5 g c. 50 g d. 500 g
c
13. How many grams of NaCl are needed to prepare 1000 mL of a 0.5 M solution of NaCl? a. 5 g b. 15 g c. 29 g d. 58.4 g
c
17. How is a 25% w/w solution prepared? a. 0.25 g solute and 75 g solvent b. 2.5 g solute and 97.5 g solvent c. 25 g solute and 75 g solvent d. 75 g solute and 25 g solvent
c
18. How many milliliters (mL) of bleach in an original bottle are needed to prepare a 10% solution? a. 0.1 mL bleach and 100 mL water b. 1.0 mL bleach and 90 mL water c. 10 mL bleach and 90 mL water d. Bleach is already a 10% solution in the original bottle
c
22. If only 25 mL of a 9% saline solution is available in the laboratory, how many mL of 5% saline solution can be prepared using all available saline solution? a. 4.5 mL b. 25.0 mL c. 45.0 mL d. 100 mL
c
26. If a glucose standard solution contains 10 mg/dL of glucose, a 1:10 dilution of this standard contains how much glucose? a. 0.01 mg/dL b. 0.1 mg/dL c. 1 mg/dL d. None of the above
c
6. Molarity is: a. The amount of one substance relative to the amounts of other substances in the solution b. Relative concentrations of the components of a mixture c. The gram-molecular mass (or weight) of a compound per liter of solution d. Expression of one amount relative to another amount
c
31. Which of the following "recipes" gives you a 1:5 dilution? a. 0.25 mL serum + 4.75 mL of diluent b. 2 mL of serum + 18 mL of diluent c. 0.25 mL serum + 1 mL of diluent d. 1.5 mL serum + 13.5 mL of diluent 32. The dilution created by answer d. in Question #31 is: a. 1:20 b. 1:10 c. 1:100 d. 1:1000
c, b
1. How would 6.32 be rounded off to one less decimal place? a. 6.32 b. 6.4 c. 7.0 d. 6.3
d
19. What is the dilution factor if 0.5 mL of serum is added to 2 mL of diluent? a. 0.5 b. 1.5 c. 2.5 d. 5
d
21. A ratio is: a. The amount of one substance relative to the amounts of other substances in the solution b. Relative concentrations of the components of a mixture c. The gram-molecular mass (or weight) of a compound per liter of solution d. Expression of one amount relative to another amount
d
25. If 0.1 mL of serum, 5 mL of reagent, and 4.9 mL of distilled water are mixed together, what is the dilution of the serum in the final solution? a. 1:5 b. 1:10 c. 1:50 d. 1:100
d
4. The exponent 10^-2 represents: a. 100 b. 1000 c. 0.1 d. 0.01
d
5. A unique characteristic of specific gravity versus density is that specific gravity is: a. The amount of matter per unit volume of a substance b. That all substances have this property c. That it represents size of substance d. That it is applicable only to solutions
d
