Q: A patient is prescribed 1.25 g of amoxicillin. If each tablet contains 250 mg, how many tablets should the patient take? (Report your answer with the correct number of significant figures.)

$$1.25\ \mathrm{g} \times \frac{1000\ \mathrm{mg}}{1\ \mathrm{g}} \times \frac{1\ \mathrm{tablet}}{250\ \mathrm{mg}} = 5.0\ \mathrm{tablets}$$

Q: A sample of mercury has a mass of $$1.50 \times 10^2$\ \mathrm{g}$$ and occupies a volume of $$11.0\ \mathrm{cm}^3. $$What is the density of mercury in $$\mathrm{g}/\mathrm{L}$$? (Note: $$1\ \mathrm{cm}^3 = 1\ \mathrm{mL}$$, $$1\ \mathrm{L} = 1000\ \mathrm{mL})$$

$$\frac{1.50 \times 10^2$\ \mathrm{g}}{11.0\ \mathrm{cm}^3} \times \frac{1000\ \mathrm{cm}^3}{1\ \mathrm{L}} = 1.36 \times 10^4$\ \mathrm{g}/\mathrm{L}$$

Q: Convert $$300.0\ \mathrm{mL} to $$gallons. ($$1\ \mathrm{gallon} = 3.785\ \mathrm{L}$$, $$1\ \mathrm{L} = 1000\ \mathrm{mL})$$

$$300.0\ \mathrm{mL} \times \frac{1\ \mathrm{L}}{1000\ \mathrm{mL}} \times \frac{1\ \mathrm{gallon}}{3.785\ \mathrm{L}} = 0.0793\ \mathrm{gallons}$$

Q: A child is prescribed 160 mg of ibuprofen. If the available suspension contains 100 mg per 5 mL, how many milliliters should be administered?

$$160\ \mathrm{mg} \times \frac{5\ \mathrm{mL}}{100\ \mathrm{mg}} = 8.0\ \mathrm{mL}$$

Q: A hospital has 125 deciliters of blood plasma. What is the volume in liters?

$$125\ \mathrm{dL} \times \frac{1\ \mathrm{L}}{10\ \mathrm{dL}} = 12.5\ \mathrm{L}$$

Q: A chemist synthesized 1.405 g of aspirin in the lab. If each tablet contains 350 mg, how many tablets did she prepare? (Report your answer with the correct number of significant figures.)

$$1.405\ \mathrm{g} \times \frac{1000\ \mathrm{mg}}{1\ \mathrm{g}} \times \frac{1\ \mathrm{tablet}}{350\ \mathrm{mg}} = 4.01\ \mathrm{tablets}$$

Q: A patient weighing 133 lb is prescribed isotretinoin at a dose of 0.5 mg/kg. How many 20 mg tablets are needed for a single dose? ($$1\ \mathrm{lb} = 0.454\ \mathrm{kg})$$

$$133\ \mathrm{lb} \times \frac{0.454\ \mathrm{kg}}{1\ \mathrm{lb}} \times \frac{0.5\ \mathrm{mg}}{1\ \mathrm{kg}} \times \frac{1\ \mathrm{tablet}}{20\ \mathrm{mg}} = 1.5\ \mathrm{tablets}$$

Question 1

Which of the following statements best describes the difference between accuracy and precision in scientific measurements?

Accepted Answer

Accuracy refers to how close a measurement is to the true value, while precision refers to how close repeated measurements are to each other.

Question 2

A patient is prescribed 1.25 g of amoxicillin. If each tablet contains 250 mg, how many tablets should the patient take? (Report your answer with the correct number of significant figures.)

Accepted Answer

$$1.25\ \mathrm{g} 	imes \frac{1000\ \mathrm{mg}}{1\ \mathrm{g}} 	imes \frac{1\ \mathrm{tablet}}{250\ \mathrm{mg}} = 5.0\ \mathrm{tablets}$$

Question 3

Which of the following is the correct SI base unit for measuring the amount of a substance?

Accepted Answer

Mole ($$\mathrm{mol})$$

Question 4

A sample of mercury has a mass of $$1.50 	imes 10^2$\ \mathrm{g}$$ and occupies a volume of $$11.0\ \mathrm{cm}^3. $$What is the density of mercury in $$\mathrm{g}/\mathrm{L}$$? (Note: $$1\ \mathrm{cm}^3 = 1\ \mathrm{mL}$$, $$1\ \mathrm{L} = 1000\ \mathrm{mL})$$

Accepted Answer

$$\frac{1.50 	imes 10^2$\ \mathrm{g}}{11.0\ \mathrm{cm}^3} 	imes \frac{1000\ \mathrm{cm}^3}{1\ \mathrm{L}} = 1.36 	imes 10^4$\ \mathrm{g}/\mathrm{L}$$

Question 5

Convert $$300.0\ \mathrm{mL} to $$gallons. ($$1\ \mathrm{gallon} = 3.785\ \mathrm{L}$$, $$1\ \mathrm{L} = 1000\ \mathrm{mL})$$

Accepted Answer

$$300.0\ \mathrm{mL} 	imes \frac{1\ \mathrm{L}}{1000\ \mathrm{mL}} 	imes \frac{1\ \mathrm{gallon}}{3.785\ \mathrm{L}} = 0.0793\ \mathrm{gallons}$$

Question 6

Which of the following numbers contains three significant figures?

Accepted Answer

0.00570

Question 7

A child is prescribed 160 mg of ibuprofen. If the available suspension contains 100 mg per 5 mL, how many milliliters should be administered?

Accepted Answer

$$160\ \mathrm{mg} 	imes \frac{5\ \mathrm{mL}}{100\ \mathrm{mg}} = 8.0\ \mathrm{mL}$$

Question 8

Which of the following is an example of an exact number?

Accepted Answer

There are exactly 12 eggs in a dozen.

Question 9

A hospital has 125 deciliters of blood plasma. What is the volume in liters?

Accepted Answer

$$125\ \mathrm{dL} 	imes \frac{1\ \mathrm{L}}{10\ \mathrm{dL}} = 12.5\ \mathrm{L}$$

Question 10

Which of the following is the correct relationship for converting Celsius to Kelvin?

Accepted Answer

$$K = ^\circ C + 273.15$$

Question 11

A chemist synthesized 1.405 g of aspirin in the lab. If each tablet contains 350 mg, how many tablets did she prepare? (Report your answer with the correct number of significant figures.)

Accepted Answer

$$1.405\ \mathrm{g} 	imes \frac{1000\ \mathrm{mg}}{1\ \mathrm{g}} 	imes \frac{1\ \mathrm{tablet}}{350\ \mathrm{mg}} = 4.01\ \mathrm{tablets}$$

Question 12

Which of the following is the correct scientific notation for the number 0.0002650?

Accepted Answer

$$2.650 	imes 10$$^{-4}$$

Question 13

A patient weighing 133 lb is prescribed isotretinoin at a dose of 0.5 mg/kg. How many 20 mg tablets are needed for a single dose? ($$1\ \mathrm{lb} = 0.454\ \mathrm{kg})$$

Accepted Answer

$$133\ \mathrm{lb} 	imes \frac{0.454\ \mathrm{kg}}{1\ \mathrm{lb}} 	imes \frac{0.5\ \mathrm{mg}}{1\ \mathrm{kg}} 	imes \frac{1\ \mathrm{tablet}}{20\ \mathrm{mg}} = 1.5\ \mathrm{tablets}$$

Question 14

Which of the following is the correct density equation?

Accepted Answer

$$d = \frac{m}{V}$$

Question 15

A liquid has a density of $$0.791\ \mathrm{g}/\mathrm{mL}. $$What is the volume occupied by $$65.0\ \mathrm{g} of $$this liquid?

Accepted Answer

$$\frac{65.0\ \mathrm{g}}{0.791\ \mathrm{g}/\mathrm{mL}} = 82.2\ \mathrm{mL}$$

Question 16

Which of the following is NOT a base SI unit?

Accepted Answer

Liter ($$\mathrm{L})$$

Question 17

A single 1-oz serving of tortilla chips contains 250 mg of sodium. If an individual ate the entire 13-oz bag, how many grams of sodium would be consumed?

Accepted Answer

$$250\ \mathrm{mg/oz} 	imes 13\ \mathrm{oz} 	imes \frac{1\ \mathrm{g}}{1000\ \mathrm{mg}} = 3.25\ \mathrm{g}$$

Chemistry and Measurement: Fundamental Concepts and Applications

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