$$4.09 \\times 10$$^{23}$$ atoms

Question 1

Which of the following best describes an element?

Accepted Answer

A substance that contains only one type of atom and cannot be broken down by chemical means.

Question 2

A sample of lead (Pb) has a mass of 22.7 g and a volume of 2.0 cm$$^3. $$What is the density of the sample?

Accepted Answer

$$11.35\ \text{g/cm}^3$$

Question 3

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

Accepted Answer

Melting point

Question 4

A 153 g rectangular solid has edge lengths 8.2 cm, 5.1 cm, and 4.7 cm. Will this object sink in water? (Density of water = $$1.00\ \text{g/cm}^3)$$

Accepted Answer

Yes, because its density is greater than water.

Question 5

Which separation technique would be most effective for separating iron filings from sand?

Accepted Answer

Magnet

Question 6

Which of the following is a chemical change?

Accepted Answer

Burning paper

Question 7

A compound contains 12.1% carbon, 16.2% oxygen, and 71.7% chlorine by mass. If you have a 254 g sample, how many grams of chlorine are present?

Accepted Answer

$$182.1\ \text{g}$$

Question 8

Which statement about mixtures is correct?

Accepted Answer

Mixtures can be separated by physical means.

Question 9

Which of the following is an example of a homogeneous mixture?

Accepted Answer

Salt water

Question 10

How many atoms are in 0.68 moles of zinc? ($$1\ \text{mol} = 6.02 \times 10$$^{23}$$ atoms)

Accepted Answer

$$4.09 \times 10$$^{23}$$ atoms

Question 11

Which property is intensive?

Accepted Answer

Density

Question 12

Which of the following changes is exothermic?

Accepted Answer

Water freezing

Question 13

A 119.5 g solid cylinder has a radius of 1.8 cm and a height of 1.5 cm. What is its density?

Accepted Answer

$$7.87\ \text{g/cm}^3$$

Question 14

Which of the following is a diatomic element?

Accepted Answer

O$$_2$$

Question 15

Which statement best describes the Law of Conservation of Energy?

Accepted Answer

Energy cannot be created or destroyed, only transformed.

Question 16

Which of the following is an example of an alloy?

Accepted Answer

14K gold

Question 17

A 550 g sample of chromium(III) oxide (Cr$$_2O$_3) $$has 378 g Cr. How many grams of Cr are in a 212 g sample?

Accepted Answer

$$145.6\ \text{g}$$

Question 18

Which of the following is NOT a pure substance?

Accepted Answer

Bronze

Question 19

Which process is used to separate a homogeneous mixture based on differences in boiling points?

Accepted Answer

Distillation

Question 20

How many moles are in $$3.79 \times 10$$^{23}$$ atoms of zinc?

Accepted Answer

$$0.63$$ moles

Question 21

Which of the following is a polyatomic element?

Accepted Answer

Sulfur (S$$_8)$$

Fundamental Concepts in General Chemistry: Matter, Classification, Properties, and the Mole

Study Guide - Practice Questions