Ch19 (Glencoe) - Balancing Chemical Equations

Question 1

How many carbon atoms are represented below?

CH₄

Answer 1

1

This is a molecule of methane. The carbon atom is the black atom in the center. The other 4 atoms are hydrogen atoms.

CH₄

Question 2

How many oxygen atoms are represented below?

2O₂

Answer 2

4

(Count the 4 red atoms in the two oxygen molecules)

Question 3

How many carbon atoms are represented below?

CO₂

Answer 3

1

CO₂ is called carbon dioxide. It has one carbon atom.

(Carbon is the black atom in the middle)

Question 4

How many water molecules are represented below?

2H₂O

Answer 4

2

“2H₂O” means 2 water molecules

Question 5

How many atoms, total, are represented below?

CH₄ + 2O₂

Answer 5

9

(There are 9 atoms total. Count ‘em)

Question 6

How would you represent the molecule below in a chemical equation?

Answer 6

CH₄

Question 7

How would you represent what is below in a chemical equation?

“Two Molecules of Oxygen”

Answer 7

2O₂

Question 8

Look at the chemical equation below. How many molecules of methane (CH₄) are shown?

CH₄ + 2O₂ → CO₂ + 2H₂O

Answer 8

1

Question 9

How would you represent what is below in a chemical equation?

“Two molecules of water”

Answer 9

2H₂O

Question 10

How would you represent what is below in a chemical equation?

Answer 10

CO₂

Question 11

How would you represent what is below in a chemical equation?

Answer 11

CO₂ + 2H₂O

Question 12

How would you represent what is below in a chemical equation?

Answer 12

CH₄ + 20₂

Question 13

What is the chemical formula for this compound?

Answer 13

Fe₂O₃

Question 14

What is the chemical formula for this?

Answer 14

3Fe₂O₃

(3 molecules of Iron Oxide)

Question 15

What is the chemical formula for this?

Answer 15

4Na

(Four individual atoms of Sodium)

Question 16

What is the chemical formula for this?

Answer 16

ZnCl₂

(One molecule of zinc chloride)

Question 17

What is the chemical formula for this?

Answer 17

4ZnCl_{<span>2</span>}

(Four molecules of zinc chloride)

Question 18

What is the chemical formula for this?

Answer 18

NaCl

Question 19

What is the chemical formula for this?

Answer 19

3NaCl

Question 20

What is the chemical formula for this?

Answer 20

Cl₂

(One molecule of chlorine)

Question 21

What is the chemical formula for this?

Answer 21

5Cl₂

(5 molecules of chlorine)

Question 22

What is the chemical formula for this?

Answer 22

Zn(OH)₂

(One molecule of zinc hydroxide)

Question 23

What is the chemical formula for this?

Answer 23

3Zn(OH)_{<span>2</span>}

(3 molecules of zinc hydroxide)

Question 24

What is the chemical formula for this?

Answer 24

CaBr₂

(one molecule of calcium bromide)

Question 25

What is the chemical formula for this?

Answer 25

3CaBr₂

(3 molecules of calcium bromide)

Question 26

What is the chemical formula for this?

Answer 26

H_{<span>2</span>}0

(One molecule of water)

Question 27

What is the chemical formula for this?

Answer 27

6H₂0

(6 molecules of water)

Question 28

You will see this little guy often. What is he?

Answer 28

Hydroxide

(Oxygen and Hydrogen pair up like this so often, we sometimes just treat them like a single object.)

Question 29

What is the chemical formula for this?

Answer 29

3OH

Question 30

What is the chemical formula for this?

Answer 30

Al(OH)₃

(one molecule of aluminum hydroxide)

Question 31

What is the chemical formula for this?

Answer 31

2Al(OH)₃

(2 molecules of aluminum hydroxide)