Question 1

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

Accepted Answer

The density of gold

Question 2

Which statement best describes a chemical property?

Accepted Answer

It can be evaluated only by changing the chemical composition of a substance.

Question 3

A student mixes salt and water, creating a solution. According to the classification of matter, this solution is best described as:

Accepted Answer

A homogeneous mixture

Question 4

Which of the following is a pure substance?

Accepted Answer

Oxygen gas ($$O_2)$$

Question 5

Which of the following best illustrates the Law of Conservation of Mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 6

Which of the following is NOT a correct classification of matter?

Accepted Answer

Air as a compound

Question 7

A sample of matter is uniform throughout and can be separated into two substances by a physical process. How should it be classified?

Accepted Answer

Homogeneous mixture

Question 8

Which of the following changes is a chemical change?

Accepted Answer

Burning of wood

Question 9

If 10 g of hydrogen reacts with 80 g of oxygen to form water, what is the total mass of water produced according to the Law of Conservation of Mass?

Accepted Answer

$$90\ \mathrm{g}$$

Question 10

Which of the following is a chemical property of hydrogen gas?

Accepted Answer

It reacts explosively with oxygen.

Question 11

A mixture of sand and iron filings can be separated by using a magnet. This is an example of separating:

Accepted Answer

A heterogeneous mixture

Question 12

Which of the following statements about compounds is correct?

Accepted Answer

They can be broken down into simpler substances by chemical means.

Question 13

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

Accepted Answer

Salad with lettuce, tomatoes, and cucumbers

Question 14

Which process involves a physical change only?

Accepted Answer

Evaporation of alcohol

Question 15

A student claims that when sugar dissolves in water, a new substance is formed. Which concept best refutes this claim?

Accepted Answer

Dissolving is a physical change, not a chemical change.

Question 16

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

Accepted Answer

A compound has a fixed composition, while a mixture does not.

Question 17

Which of the following is a correct application of the Law of Conservation of Mass in a real-world scenario?

Accepted Answer

In a closed system, the mass of burning wood and the resulting ash and gases remains constant.

Question 18

Which of the following is NOT a physical property?

Accepted Answer

Ability to react with acid

Question 19

A sample of matter is made up of only one kind of atom. How is it classified?

Accepted Answer

Element

Question 20

Which of the following best explains why the mass of a sealed container does not change during a chemical reaction inside it?

Accepted Answer

The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction.

Fundamental Concepts in General Chemistry: Properties, Classification of Matter, and Laws of Chemical Combination

Study Guide - Practice Questions