Question 1

Which of the following best describes a molecule of $$\mathrm{H_2SO_4} in $$terms of its atomic composition?

Accepted Answer

It contains 2 atoms of hydrogen, 1 atom of sulfur, and 4 atoms of oxygen.

Question 2

If you have 3 molecules of $$\mathrm{Ca_3$(PO_4$)_2}$$, how many oxygen atoms are present?

Accepted Answer

$$24$$ oxygen atoms

Question 3

Which statement correctly distinguishes a pure substance from a mixture?

Accepted Answer

A pure substance has a fixed composition and constant properties, while a mixture has variable composition and properties.

Question 4

How many atoms are present in 2 molecules of $$\mathrm{H_2SO_4}$$?

Accepted Answer

$$20$$ atoms

Question 5

Which of the following is an example of a simple pure substance?

Accepted Answer

$$\mathrm{O_2$}$$

Question 6

What is the atomicity of glucose ($$\mathrm{C_6H_{12}O_6$}$$)?

Accepted Answer

$$24$$

Question 7

Which property is NOT characteristic of a mixture?

Accepted Answer

Fixed composition

Question 8

A metallic bond is best described as:

Accepted Answer

A lattice of positive ions surrounded by a sea of delocalized electrons.

Question 9

Which of the following is a correct example of a compound?

Accepted Answer

$$\mathrm{H_2O}$$

Question 10

If you have 5 molecules of $$\mathrm{$$CaSO_4$$ \cdot 5H_2O}$$, how many hydrogen atoms are present?

Accepted Answer

$$50$$ hydrogen atoms

Question 11

Which of the following statements about pure substances is correct?

Accepted Answer

They have constant melting and boiling points.

Question 12

What is the total number of atoms in 3 molecules of $$\mathrm{C_6H_{12}O_6$}$$?

Accepted Answer

$$72$$ atoms

Question 13

Which of the following is NOT a characteristic of a pure substance?

Accepted Answer

Variable composition

Question 14

Which of the following is a mixture?

Accepted Answer

Air

Question 15

How many phosphorus atoms are present in 3 molecules of $$\mathrm{Ca_3$(PO_4$)_2}$$?

Accepted Answer

$$6$$ phosphorus atoms

Question 16

Which of the following is a correct example of a mixture?

Accepted Answer

Salt water

Question 17

What is the coefficient in the formula $$2 \mathrm{H_2SO_4}$$ and what does it represent?

Accepted Answer

The coefficient is $$2$$ and it represents the number of molecules.

Question 18

Which of the following is NOT a simple substance?

Accepted Answer

$$\mathrm{H_2O}$$

Question 19

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

Accepted Answer

A compound has a fixed ratio of elements, while a mixture has variable ratios.

Question 20

Which of the following is an example of a metallic bond?

Accepted Answer

Bonding in magnesium metal ($$\mathrm{Mg})$$

Atoms, Molecules, and Classification of Substances

Study Guide - Practice Questions