Question 1

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

Accepted Answer

Density

Question 2

A property that can only be observed by changing the chemical composition of a substance is called:

Accepted Answer

Chemical property

Question 3

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture with uniform composition throughout

Question 4

According to the law of conservation of mass, which equation is correct for a chemical reaction?

Accepted Answer

$$m_\mathrm{reactants} = m_\mathrm{products}$$

Question 5

Which of the following is NOT a pure substance?

Accepted Answer

Air

Question 6

Which statement about mixtures is correct?

Accepted Answer

Mixtures can be separated by physical means.

Question 7

Which of the following is a chemical property?

Accepted Answer

Ability to react with oxygen

Question 8

A student mixes sand and salt. Which type of matter is formed?

Accepted Answer

Heterogeneous mixture

Question 9

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 closed system.

Question 10

Which of the following is classified as a compound?

Accepted Answer

Water

Question 11

Which process is a physical change?

Accepted Answer

Melting of ice

Question 12

Which of the following statements is true about elements?

Accepted Answer

Elements consist of only one type of atom.

Question 13

A sample of matter has a uniform and definite composition. It is best classified as:

Accepted Answer

Pure substance

Question 14

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

Accepted Answer

Salad

Question 15

Which of the following changes would NOT be considered a chemical change?

Accepted Answer

Boiling water

Question 16

If 10 g of hydrogen reacts with 80 g of oxygen to form water, what is the total mass of water formed according to the law of conservation of mass?

Accepted Answer

$$90\ \mathrm{g}$$

Question 17

Which of the following best describes a compound?

Accepted Answer

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

Question 18

Which of the following is NOT a chemical property?

Accepted Answer

Melting point

Question 19

Which of the following is a correct statement about the classification of matter?

Accepted Answer

Elements and compounds are both pure substances.

Question 20

A student observes that the mass of a closed flask does not change during a chemical reaction. This observation supports which law?

Accepted Answer

Law of Conservation of Mass

Some Basic Concepts of Chemistry (Questions test 1)

Study Guide - Practice Questions