Last night’s homework:

Problems 4-6 on page 282

Questions 7-11 on page 283

Write chemical equations for each of the following reactions.

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

FeCl3 + NaOH → Fe(OH)3 + NaCl

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

FeCl3 + NaOH → Fe(OH)3 + NaCl

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

FeCl3 + NaOH → Fe(OH)3 + NaCl

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

FeCl3 + NaOH → Fe(OH)3 + NaCl

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

FeCl3 + NaOH → Fe(OH)3 + NaCl

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

FeCl3 + NaOH → Fe(OH)3 + NaCl

4. In water, iron(III) chloride reacts with sodium hydroxide, producing solid iron(III) hydroxide and sodium chloride.

FeCl3 + NaOH → Fe(OH)3 + NaCl

FeCl3 + NaOH → Fe(OH)3 + NaCl

FeCl3 + NaOH → Fe(OH)3 + NaCl

FeClNaOH

FeClNaOH

FeCl3 + NaOH → Fe(OH)3 + NaCl

Fe 1Cl 3Na 1O 1H 1

Fe 1Cl 1Na 1O 3H 3

FeCl3 + NaOH → Fe(OH)3 + NaCl

Fe 1Cl 3Na 1O 1H 1

Fe 1Cl 1Na 1O 3H 3

FeCl3 + NaOH → Fe(OH)3 + 3NaCl

Fe 1Cl 3Na 1O 1H 1

Fe 1Cl 1Na 1O 3H 3

FeCl3 + NaOH → Fe(OH)3 + 3NaCl

Fe 1Cl 3Na 1O 1H 1

Fe 1Cl 3Na 3O 3H 3

FeCl3 + NaOH → Fe(OH)3 + 3NaCl

Fe 1Cl 3Na 1O 1H 1

Fe 1Cl 3Na 3O 3H 3

FeCl3 + 3NaOH → Fe(OH)3 + 3NaCl

Fe 1Cl 3Na 1O 1H 1

Fe 1Cl 3Na 3O 3H 3

FeCl3 + 3NaOH → Fe(OH)3 + 3NaCl

Fe 1Cl 3Na 3O 3H 3

Fe 1Cl 3Na 3O 3H 3

FeCl3 + 3NaOH → Fe(OH)3 + 3NaCl

Fe 1Cl 3Na 3O 3H 3

Fe 1Cl 3Na 3O 3H 3

5. Liquid carbon disulfide reacts with oxygen gas, producing carbon dioxide gas and sulfur dioxide gas.

5. Liquid carbon disulfide reacts with oxygen gas, producing carbon dioxide gas and sulfur dioxide gas.

CS2 + O2 → CO2 + SO2

CS2 + O2 → CO2 + SO2

CS2 + O2 → CO2 + SO2

COS

COS

CS2 + O2 → CO2 + SO2

C 1O 4S 1

C 1O 2S 2

CS2 + O2 → CO2 + 2SO2

C 1O 4S 1

C 1O 2S 2

CS2 + O2 → CO2 + 2SO2

C 1O 6S 2

C 1O 2S 2

CS2 + 3O2 → CO2 + 2SO2

C 1O 6S 2

C 1O 2S 2

CS2 + 3O2 → CO2 + 2SO2

C 1O 6S 2

C 1O 6S 2

CS2 + 3O2 → CO2 + 2SO2

C 1O 6S 2

C 1O 6S 2

6. Solid zinc and aqueous hydrogen sulfate react to produce hydrogen gas and aqueous zinc sulfate.

6. Solid zinc and aqueous hydrogen sulfate react to produce hydrogen gas and aqueous zinc sulfate.

Zn + H2SO4 → H2 + ZnSO4

Zn + H2SO4 → H2 + ZnSO4

ZnHSO

ZnHSO

Zn + H2SO4 → H2 + ZnSO4

Zn 1H 2S 1O 4

Zn 1H 2S 1O 4

7. List three types of evidence that a chemical reaction has occurred.

7. List three types of evidence that a chemical reaction has occurred.

Changes in:

• Temperature

• Color

Appearance of:

• Odor

• Gas bubbles

• Solid precipitate

8. Compare and contrast a skeleton equation and a chemical equation.

8. Compare and contrast a skeleton equation and a chemical equation.

Both show formulas of reactants and products.

Chemical equation also shows relative amounts.

9. Why is it important that a chemical equation be balanced?

9. Why is it important that a chemical equation be balanced?

Mass is neither created nor destroyed.

10. When balancing a chemical equation, can you adjust the number that is subscripted to a substance formula?

10. When balancing a chemical equation, can you adjust the number that is subscripted to a substance formula?

No

10. When balancing a chemical equation, can you adjust the number that is subscripted to a substance formula?

NoH2O → H2 + O2

10. When balancing a chemical equation, can you adjust the number that is subscripted to a substance formula?

NoH2O → H2 + O2

H2O2 → H2 + O2

11. Why is it important that to reduce the coefficients in a balanced equation to the lowest possible whole-number ratio?

11. Why is it important that to reduce the coefficients in a balanced equation to the lowest possible whole-number ratio?

Clearly shows the relative amounts.

.