Q: Convert 0.0250 kilometers to centimeters. (1 km = 1000 m, 1 m = 100 cm)

$$2.50 \times 10^4$\ \mathrm{cm}$$

Question 1

A sample of gold has a mass of 96.5 g and a volume of 5.00 cm$$^3. $$What is the density of gold in g/cm$$^3$$?

Accepted Answer

$$19.3\ \mathrm{g/cm^3$}$$

Question 2

Which of the following is an example of a chemical change?

Accepted Answer

Burning a piece of paper

Question 3

A student measures the mass of a coin as 2.34 g, 2.36 g, and 2.35 g in three trials. The actual mass is 2.50 g. Which statement best describes the measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 4

Convert 0.0250 kilometers to centimeters. (1 km = 1000 m, 1 m = 100 cm)

Accepted Answer

$$2.50 	imes 10^4$\ \mathrm{cm}$$

Question 5

Which of the following is a homogeneous mixture?

Accepted Answer

Salt water

Question 6

A patient’s body temperature is measured as 102.2 $$^\circF. $$What is this temperature in $$^\circC$$? (Use $$^\circC$$ = ($$^\circF - 32$$) $$	imes 5/9)$$

Accepted Answer

$$39.0\ ^\circ\mathrm{C}$$

Question 7

Which of the following statements about significant figures is correct?

Accepted Answer

Zeros between nonzero digits are always significant.

Question 8

A nutrition label states that a serving contains 150 Cal. How many joules is this? (1 Cal = 1 kcal, 1 kcal = 4184 J)

Accepted Answer

$$627,600\ \mathrm{J}$$

Question 9

Which of the following best describes an element?

Accepted Answer

A pure substance that cannot be broken down into simpler substances by chemical means.

Question 10

A 50.0 g sample of metal absorbs 500 J of heat, causing its temperature to rise from 25.0 $$^\circC to 35.0$$ $$^\circC. $$What is the specific heat of the metal? (Use $$q = m c \Delta T)$$

Accepted Answer

$$1.00\ \mathrm{J/g\ ^\circ C}$$

Question 11

Which of the following is an example of a physical property?

Accepted Answer

Boiling point

Question 12

A chemist needs 0.250 L of a solution. How many milliliters is this? (1 L = 1000 mL)

Accepted Answer

$$250\ \mathrm{mL}$$

Question 13

Which of the following is a heterogeneous mixture?

Accepted Answer

Salad dressing with oil and vinegar

Question 14

A student records a measurement as $$4.560 	imes 10^3$ m. How many significant figures are in this measurement?

Accepted Answer

4

Question 15

Which of the following best describes a compound?

Accepted Answer

A pure substance composed of two or more elements chemically combined in a fixed ratio.

Question 16

A 200.0 g sample of water is heated from 20.0 $$^\circC to 30.0$$ $$^\circC. $$How much energy (in J) is absorbed? (Specific heat of water = $$4.18\ \mathrm{J/g\ ^\circ C})$$

Accepted Answer

$$8,360\ \mathrm{J}$$

Question 17

Which of the following is an exact number?

Accepted Answer

There are 12 eggs in a dozen.

Question 18

A nurse needs to administer 0.500 g of a medication. The available tablets are labeled as 250 mg each. How many tablets should the nurse give?

Accepted Answer

2 tablets

Question 19

Which of the following is a chemical property?

Accepted Answer

Ability to react with oxygen

Question 20

A sample of ethanol has a density of $$0.789\ \mathrm{g/mL}. $$What is the mass of 250.0 mL of ethanol?

Accepted Answer

$$197\ \mathrm{g}$$

Matter, Energy, and Measurement: Foundations of General Chemistry

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