Balancing Chemical Equations

Question 1

How many carbon atoms are represented below?

Answer 1

1

(There is one carbon atom in one molecule of methane. The carbon atom is the black atom in the center)

Question 2

How many oxygen atoms are represented below?

Answer 2

4

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

Question 3

How many carbon atoms are represented below?

Answer 3

1

(Its the black one in the middle)

Question 4

How many water molecules are represented below?

Answer 4

2 water molecules

Question 5

How many atoms, total, are represented below?

Answer 5

9

(count ‘em)

Question 6

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

Answer 6

Question 7

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

Answer 7

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?

Answer 9

Question 10

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

Answer 10

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

**H₂0** (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** (If these three hydroxide groups were part of a larger molecule, perhaps stuck onto an aluminum atom, you might see them represented as follows: **Al(OH)₃**

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)