Question 1

Which of the following best describes an alloy such as brass?

Accepted Answer

A homogeneous mixture of metals

Question 2

A student is given a sample of 14K gold jewelry. Which statement about this sample is correct?

Accepted Answer

It is a homogeneous mixture (alloy) of gold and other metals

Question 3

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

Accepted Answer

Reactivity with water

Question 4

A solid cylinder has a radius of 2.0 cm, a height of 5.0 cm, and a mass of 157 g. What is its density? (Use π ≈ 3.14)

Accepted Answer

2.50 g/cm³

Question 5

Which of the following statements about elements and compounds is correct?

Accepted Answer

Elements contain only one type of atom, while compounds contain two or more different atoms chemically bonded

Question 6

A sample of a substance has a mass of 50.0 g and occupies a volume of 62.5 mL. Will it float or sink in water at 4°C?

Accepted Answer

It will float, because its density is less than 1.00 g/cm³

Question 7

Which method would be most effective for separating a mixture of sand and iron filings?

Accepted Answer

Using a magnet

Question 8

Which of the following is an example of an allotrope?

Accepted Answer

O₂ and O₃ (oxygen and ozone)

Question 9

A student has 3.00 moles of carbon atoms. How many atoms does this represent?

Accepted Answer

1.81 × 10²⁴ atoms

Question 10

Which of the following is an intensive property?

Accepted Answer

Density

Question 11

Which process is endothermic?

Accepted Answer

Ice melting

Question 12

A mixture of salt and water is best classified as:

Accepted Answer

A homogeneous mixture (solution)

Question 13

Which of the following changes is a chemical change?

Accepted Answer

Electrolysis of water to produce hydrogen and oxygen gases

Question 14

A sample of neon contains 1.20 × 10²⁴ atoms. What is the mass of this sample? (Ne atomic mass ≈ 20.18 g/mol)

Accepted Answer

40.2 g

Question 15

Which of the following best explains why water boils at a constant temperature under constant pressure?

Accepted Answer

Boiling point is an intensive property

Question 16

Which of the following statements about the law of conservation of energy is correct?

Accepted Answer

Energy can be transformed from one form to another but cannot be created or destroyed

Question 17

A rectangular block has dimensions 3.0 cm × 4.0 cm × 5.0 cm and a mass of 180 g. What is its density?

Accepted Answer

3.0 g/cm³

Question 18

Which of the following is a heterogeneous mixture?

Accepted Answer

Sand in water

Question 19

Which of the following best describes the difference between a molecule and an atom?

Accepted Answer

A molecule consists of two or more atoms bonded together, while an atom is a single particle

Question 20

Which separation technique would be most appropriate to separate a mixture of ethanol and water?

Accepted Answer

Distillation

Introduction to Matter, Classification, and Basic Quantitative Chemistry

Study Guide - Practice Questions