Question 1

Which of the following best describes a compound?

Accepted Answer

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

Question 2

Which of the following statements about the periodic table is correct?

Accepted Answer

Elements are organized by increasing atomic number.

Question 3

A student measures the mass of a metal block as 45.2 g and its volume as 12.0 mL. What is the density of the block?

Accepted Answer

$$d = \frac{45.2\ \mathrm{g}}{12.0\ \mathrm{mL}} = 3.77\ \mathrm{g/mL}$$

Question 4

Which of the following is an example of an ionic bond?

Accepted Answer

The bond between sodium and chlorine in $$\mathrm{NaCl}.$$

Question 5

Which SI unit would you use to measure the amount of a chemical substance?

Accepted Answer

Mole

Question 6

A sample of gas occupies a volume of 2.50 L and has a mass of 5.00 g. What is its density?

Accepted Answer

$$d = \frac{5.00\ \mathrm{g}}{2.50\ \mathrm{L}} = 2.00\ \mathrm{g/L}$$

Question 7

Which of the following best describes the difference between an element and a compound?

Accepted Answer

A compound is made of two or more elements chemically combined, while an element consists of only one type of atom.

Question 8

Which of the following measurements contains the correct number of significant figures?

Accepted Answer

0.0400 has three significant figures.

Question 9

Which statement about the structure of an atom is correct?

Accepted Answer

Protons and neutrons are found in the nucleus; electrons orbit the nucleus.

Question 10

A chemist mixes two clear solutions and observes the formation of a white solid. What type of change has occurred?

Accepted Answer

A chemical change, because a new substance (precipitate) formed.

Question 11

Which of the following is a real-world example of a covalent bond?

Accepted Answer

The bond between hydrogen and oxygen in $$\mathrm{H_2O}.$$

Question 12

A student records the following measurements: 12.34 g, 0.0567 g, and 123.4 g. How many significant figures are in the sum of these values?

Accepted Answer

3

Question 13

Which of the following best describes the state of matter in which particles are far apart and move freely?

Accepted Answer

Gas

Question 14

A hospital stores oxygen gas in a tank with a mass of 3200 g and a volume of 2240 L. What is the density of the oxygen gas?

Accepted Answer

$$d = \frac{3200\ \mathrm{g}}{2240\ \mathrm{L}} = 1.43\ \mathrm{g/L}$$

Question 15

Which of the following is NOT an SI base unit?

Accepted Answer

Gram

Question 16

Which of the following best explains why water ($$\mathrm{H_2O}) is $$considered a pure substance?

Accepted Answer

It has a fixed composition and distinct properties.

Question 17

A student needs to convert 25.0 cm to meters using SI units. What is the correct conversion?

Accepted Answer

$$25.0\ \mathrm{cm} 	imes \frac{1\ \mathrm{m}}{100\ \mathrm{cm}} = 0.250\ \mathrm{m}$$

Question 18

Which of the following is a correct statement about significant figures in multiplication and division?

Accepted Answer

The answer should have as many significant figures as the number with the fewest significant figures.

Question 19

Which of the following best describes the process of forming an ionic bond?

Accepted Answer

A metal transfers electrons to a nonmetal.

Question 20

A sample of ethanol has a mass of 78.5 g and a volume of 100.0 mL. What is the density of ethanol?

Accepted Answer

$$d = \frac{78.5\ \mathrm{g}}{100.0\ \mathrm{mL}} = 0.785\ \mathrm{g/mL}$$

Matter, Measurement, and Atomic Structure: General Chemistry Study Notes

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