Q: A doctor prescribes 0.250 mg of a medication. The tablets available are 50 mcg each. How many tablets should the patient take?

$$0.250 \ \mathrm{mg} \times \frac{1000 \ \mathrm{mcg}}{1 \ \mathrm{mg}} \div 50 \ \mathrm{mcg} = 5$$ tablets

Q: How many centimeters are in 2.44 meters?

$$2.44 \ \mathrm{m} \times \frac{100 \ \mathrm{cm}}{1 \ \mathrm{m}} = 244 \ \mathrm{cm}$$

Q: A nurse needs to administer 2.0 teaspoons of cough syrup. If 1 tsp = 5.0 mL and the density of the syrup is 1.20 g/mL, what is the mass of syrup given?

$$2.0 \ \mathrm{tsp} \times \frac{5.0 \ \mathrm{mL}}{1 \ \mathrm{tsp}} \times \frac{1.20 \ \mathrm{g}}{1 \ \mathrm{mL}} = 12 \ \mathrm{g}$$

Q: A patient walks 7.5 km on a treadmill at a pace of 65 meters per minute. How many minutes does it take to complete the walk?

$$7.5 \ \mathrm{km} \times \frac{1000 \ \mathrm{m}}{1 \ \mathrm{km}} \div 65 \ \mathrm{m/min} = 115 \ \mathrm{min}$$

Question 1

Which of the following is the correct SI unit for measuring temperature?

Accepted Answer

Kelvin (K)

Question 2

A nurse measures a patient's mass as 72.5 kg. How many significant figures are in this measurement?

Accepted Answer

3

Question 3

Which of the following numbers contains only significant zeros?

Accepted Answer

25.300

Question 4

A doctor prescribes 0.250 mg of a medication. The tablets available are 50 mcg each. How many tablets should the patient take?

Accepted Answer

$$0.250 \ \mathrm{mg} 	imes \frac{1000 \ \mathrm{mcg}}{1 \ \mathrm{mg}} \div 50 \ \mathrm{mcg} = 5$$ tablets

Question 5

Which equality is exact and should NOT be used to determine significant figures in a calculation?

Accepted Answer

$$1 \ \mathrm{in.} = 2.54 \ \mathrm{cm}$$

Question 6

A sample of metal has a mass of 48.0 g and displaces water from 25.0 mL to 33.0 mL in a graduated cylinder. What is the density of the metal?

Accepted Answer

$$\frac{48.0 \ \mathrm{g}}{8.0 \ \mathrm{mL}} = 6.0 \ \mathrm{g/mL}$$

Question 7

Which of the following is a measured number, not an exact number?

Accepted Answer

7.902 cm (diameter of a circle)

Question 8

A patient’s urine has a specific gravity of 1.025. What does this value mean?

Accepted Answer

The urine is 1.025 times as dense as water.

Question 9

How many centimeters are in 2.44 meters?

Accepted Answer

$$2.44 \ \mathrm{m} 	imes \frac{100 \ \mathrm{cm}}{1 \ \mathrm{m}} = 244 \ \mathrm{cm}$$

Question 10

A nurse needs to administer 2.0 teaspoons of cough syrup. If 1 tsp = 5.0 mL and the density of the syrup is 1.20 g/mL, what is the mass of syrup given?

Accepted Answer

$$2.0 \ \mathrm{tsp} 	imes \frac{5.0 \ \mathrm{mL}}{1 \ \mathrm{tsp}} 	imes \frac{1.20 \ \mathrm{g}}{1 \ \mathrm{mL}} = 12 \ \mathrm{g}$$

Question 11

Which of the following is the correct equality for the prefix 'centi-'?

Accepted Answer

$$1 \ \mathrm{cm} = 0.01 \ \mathrm{m}$$

Question 12

If a solution contains 1.9% omega-3 fatty acids by mass, how many grams of omega-3 are in 100 g of the solution?

Accepted Answer

1.9 g

Question 13

A patient walks 7.5 km on a treadmill at a pace of 65 meters per minute. How many minutes does it take to complete the walk?

Accepted Answer

$$7.5 \ \mathrm{km} 	imes \frac{1000 \ \mathrm{m}}{1 \ \mathrm{km}} \div 65 \ \mathrm{m/min} = 115 \ \mathrm{min}$$

Question 14

Which of the following is the correct way to round 3.1457 g to three significant figures?

Accepted Answer

3.15 g

Question 15

Which of the following statements about density is correct?

Accepted Answer

Density is the ratio of mass to volume.

Question 16

How many minutes are in 1.4 days?

Accepted Answer

$$1.4 \ \mathrm{days} 	imes \frac{24 \ \mathrm{h}}{1 \ \mathrm{day}} 	imes \frac{60 \ \mathrm{min}}{1 \ \mathrm{h}} = 2,016 \ \mathrm{min}$$

Question 17

Which of the following is the correct conversion factor for the equality 1 L = 1000 mL?

Accepted Answer

Both $$\frac{1 \ \mathrm{L}}{1000 \ \mathrm{mL}}$$ and $$\frac{1000 \ \mathrm{mL}}{1 \ \mathrm{L}}$$

Question 18

A 14.7-g sample of an unknown liquid has a density of 1.32 g/mL. What is the volume of the sample?

Accepted Answer

$$\frac{14.7 \ \mathrm{g}}{1.32 \ \mathrm{g/mL}} = 11.1 \ \mathrm{mL}$$

Chapter 2: Chemistry and Measurements – GOB Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard