Q: A medication is available in 250 mg capsules. If a patient needs 1.5 g of the medication, how many capsules should be administered?

$$\frac{1.5\ \text{g} \times 1000\ \text{mg/g}}{250\ \text{mg/capsule}} = 6$$ capsules

Q: Which equality is used to convert between pounds and kilograms?

$$2.20\ \text{lb} = 1\ \text{kg}$$

Q: A jewelry piece contains 18% gold by mass. If the piece has a total mass of 50 g, how many grams of gold does it contain?

$$50\ \text{g} \times 0.18 = 9\ \text{g}$$

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

The equality $$1\ \text{in.} = 2.54\ \text{cm}$$

Q: A car travels at a speed of 85 km/h. How many meters does it travel in 2 hours?

$$85\ \text{km/h} \times 2\ \text{h} \times 1000\ \text{m/km} = 170,000\ \text{m}$$

Q: Which conversion factor would you use to convert centimeters to meters?

$$\frac{1\ \text{m}}{100\ \text{cm}}$$

Q: A food label states that a can of tuna contains 1.9% omega-3 fatty acids by mass. If the can contains 150 g of tuna, how many grams of omega-3 fatty acids are present?

$$150\ \text{g} \times 0.019 = 2.85\ \text{g}$$

Q: Which of the following conversion factors is correct for the equality $$60\ \text{min} = 1\ \text{h}$$?

$$\frac{1\ \text{h}}{60\ \text{min}}$$

Q: A solution contains 5 ppm of lead. How many micrograms of lead are present in 2 kg of solution?

$$2\ \text{kg} \times 5\ \text{\mu g/g} \times 1000\ \text{g/kg} = 10,000\ \text{\mu g}$$

Question 1

Which of the following statements about conversion factors is TRUE?

Accepted Answer

Conversion factors between two metric units are based on definitions and are considered exact numbers.

Question 2

A medication is available in 250 mg capsules. If a patient needs 1.5 g of the medication, how many capsules should be administered?

Accepted Answer

$$\frac{1.5\ 	ext{g} 	imes 1000\ 	ext{mg/g}}{250\ 	ext{mg/capsule}} = 6$$ capsules

Question 3

Which equality is used to convert between pounds and kilograms?

Accepted Answer

$$2.20\ 	ext{lb} = 1\ 	ext{kg}$$

Question 4

A jewelry piece contains 18% gold by mass. If the piece has a total mass of 50 g, how many grams of gold does it contain?

Accepted Answer

$$50\ 	ext{g} 	imes 0.18 = 9\ 	ext{g}$$

Question 5

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

Accepted Answer

The equality $$1\ 	ext{in.} = 2.54\ 	ext{cm}$$

Question 6

A car travels at a speed of 85 km/h. How many meters does it travel in 2 hours?

Accepted Answer

$$85\ 	ext{km/h} 	imes 2\ 	ext{h} 	imes 1000\ 	ext{m/km} = 170,000\ 	ext{m}$$

Question 7

Which conversion factor would you use to convert centimeters to meters?

Accepted Answer

$$\frac{1\ 	ext{m}}{100\ 	ext{cm}}$$

Question 8

A food label states that a can of tuna contains 1.9% omega-3 fatty acids by mass. If the can contains 150 g of tuna, how many grams of omega-3 fatty acids are present?

Accepted Answer

$$150\ 	ext{g} 	imes 0.019 = 2.85\ 	ext{g}$$

Question 9

Which of the following conversion factors is correct for the equality $$60\ 	ext{min} = 1\ 	ext{h}$$?

Accepted Answer

$$\frac{1\ 	ext{h}}{60\ 	ext{min}}$$

Question 10

A solution contains 5 ppm of lead. How many micrograms of lead are present in 2 kg of solution?

Accepted Answer

$$2\ 	ext{kg} 	imes 5\ 	ext{\mu g/g} 	imes 1000\ 	ext{g/kg} = 10,000\ 	ext{\mu g}$$

Question 11

Which of the following numbers would NOT be used to determine significant figures in a calculation?

Accepted Answer

The conversion factor $$1\ 	ext{m} = 100\ 	ext{cm}$$

Question 12

If a gasoline price is $3.40 per gallon, which number is considered a measured value?

Accepted Answer

$$3.40$$

Question 13

Which of the following is a correct conversion factor for the equality $$1\ 	ext{lb} = 16\ 	ext{oz}$$?

Accepted Answer

$$\frac{16\ 	ext{oz}}{1\ 	ext{lb}}$$

Question 14

A patient is prescribed 500 mg of a drug. The drug is available as 0.25 g tablets. How many tablets should the patient take?

Accepted Answer

$$\frac{500\ 	ext{mg}}{250\ 	ext{mg/tablet}} = 2$$ tablets

Question 15

Which of the following statements about significant figures is correct?

Accepted Answer

Measured numbers are always counted toward significant figures.

Question 16

A person has 18% body fat by mass. If their total body mass is 70 kg, what is their body fat mass?

Accepted Answer

$$70\ 	ext{kg} 	imes 0.18 = 12.6\ 	ext{kg}$$

Question 17

Which of the following is a correct conversion factor for the equality $$1\ 	ext{m} = 1000\ 	ext{mm}$$?

Accepted Answer

$$\frac{1000\ 	ext{mm}}{1\ 	ext{m}}$$

Question 18

A package lists its contents as 2.20 lb (1 kg). Which number is exact and which is measured?

Accepted Answer

Both 2.20 and 1 are measured

Chemistry and Measurements: Equalities and Conversion Factors

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