Q: A woman is 5 foot, 3 inches tall. What is her height in centimeters? (1 inch = 2.54 cm)

$$5 \times 12 + 3 = 63$$ inches; $$63 \times 2.54 = 160 cm$$

Q: A platinum ring has a mass of 44.430 mg and displaces 0.00423 mL of water. What is its density in g/mL?

$$\frac{44.430\ \text{mg}}{0.00423\ \text{mL}} \times \frac{1\ \text{g}}{1000\ \text{mg}} = 10.5\ \text{g/mL}$$

Q: When multiplying 2.46 cm by 0.35 cm, what is the correct answer with the proper number of significant figures?

$$2.46 \times 0.35 = 0.861$$; answer: $$0.86 cm$^2$$

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

$$1\ \text{inch} = 2.54\ \text{cm}$$

Q: A car averages 35 miles per gallon of gasoline. How many liters of gasoline are needed for a trip of 450 km? (1 mile = 1.609 km, 1 gal = 3.78 L)

$$450\ \text{km} \times \frac{1\ \text{mile}}{1.609\ \text{km}} \times \frac{1\ \text{gal}}{35\ \text{miles}} \times \frac{3.78\ \text{L}}{1\ \text{gal}} = 30\ \text{L}$$

Q: A patient has 232 mg of cholesterol per 100.0 mL of blood. If the patient has 5.2 L of blood, how many grams of cholesterol are present?

$$5.2\ \text{L} \times \frac{1000\ \text{mL}}{1\ \text{L}} \times \frac{232\ \text{mg}}{100.0\ \text{mL}} \times \frac{1\ \text{g}}{1000\ \text{mg}} = 12.1\ \text{g}$$

Q: A sapphire weighs 330 carats. What is its mass in grams? (1 carat = 200 mg)

$$330\ \text{carats} \times 200\ \text{mg/carats} \times \frac{1\ \text{g}}{1000\ \text{mg}} = 66.0\ \text{g}$$

Question 1

Which of the following statements best describes an element?

Accepted Answer

An element is made up of only one type of atom and has a constant composition.

Question 2

Which of the following is a compound?

Accepted Answer

NaCl

Question 3

Only five elements make up 90% of the Earth's crust by mass. Which element is the most abundant?

Accepted Answer

Oxygen

Question 4

Which of the following is the correct SI base unit for mass?

Accepted Answer

kilogram (kg)

Question 5

A woman is 5 foot, 3 inches tall. What is her height in centimeters? (1 inch = 2.54 cm)

Accepted Answer

$$5 	imes 12 + 3 = 63$$ inches; $$63 	imes 2.54 = 160 cm$$

Question 6

Which temperature scale is defined by the equation $$K = ^\circ C + 273.15$$?

Accepted Answer

Kelvin

Question 7

A platinum ring has a mass of 44.430 mg and displaces 0.00423 mL of water. What is its density in g/mL?

Accepted Answer

$$\frac{44.430\ 	ext{mg}}{0.00423\ 	ext{mL}} 	imes \frac{1\ 	ext{g}}{1000\ 	ext{mg}} = 10.5\ 	ext{g/mL}$$

Question 8

Which of the following numbers has 4 significant figures?

Accepted Answer

0.05930

Question 9

When multiplying 2.46 cm by 0.35 cm, what is the correct answer with the proper number of significant figures?

Accepted Answer

$$2.46 	imes 0.35 = 0.861$$; answer: $$0.86 cm$^2$$

Question 10

A child has a temperature of 40.00 $$^\circC. $$What is this temperature in Kelvin?

Accepted Answer

$$40.00 + 273.15 = 313.15 K$$

Question 11

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

Accepted Answer

$$1\ 	ext{inch} = 2.54\ 	ext{cm}$$

Question 12

A car averages 35 miles per gallon of gasoline. How many liters of gasoline are needed for a trip of 450 km? (1 mile = 1.609 km, 1 gal = 3.78 L)

Accepted Answer

$$450\ 	ext{km} 	imes \frac{1\ 	ext{mile}}{1.609\ 	ext{km}} 	imes \frac{1\ 	ext{gal}}{35\ 	ext{miles}} 	imes \frac{3.78\ 	ext{L}}{1\ 	ext{gal}} = 30\ 	ext{L}$$

Question 13

Which of the following prefixes and their multipliers are correctly matched?

Accepted Answer

milli: $$10^{-3}$$, mega: $$10^{6}$$

Question 14

A patient has 232 mg of cholesterol per 100.0 mL of blood. If the patient has 5.2 L of blood, how many grams of cholesterol are present?

Accepted Answer

$$5.2\ 	ext{L} 	imes \frac{1000\ 	ext{mL}}{1\ 	ext{L}} 	imes \frac{232\ 	ext{mg}}{100.0\ 	ext{mL}} 	imes \frac{1\ 	ext{g}}{1000\ 	ext{mg}} = 12.1\ 	ext{g}$$

Question 15

Which of the following statements about significant figures is correct?

Accepted Answer

Zeros at the end of a number are significant if a decimal point is written in the number.

Question 16

A sapphire weighs 330 carats. What is its mass in grams? (1 carat = 200 mg)

Accepted Answer

$$330\ 	ext{carats} 	imes 200\ 	ext{mg/carats} 	imes \frac{1\ 	ext{g}}{1000\ 	ext{mg}} = 66.0\ 	ext{g}$$

Question 17

Which of the following is the correct formula for density?

Accepted Answer

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

Chapter 1: Matter, Measurements, and Problem Solving – General Chemistry Study Notes

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