1. Chemical Equations
Part I

2. Chemical Change
One or more substances are converted into different substances.
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3. Chemical Reaction
One or more substances are converted into different substances.
represented with chemical equations
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4. Indicators of a Chemical Reaction
Evolution of heat and light
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5. Indicators of a Chemical Reaction
Production of a gas
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6. Indicators of a Chemical Reaction
Formation of a precipitate
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7. Indicators of a Chemical Reaction
Color Change
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8. Halogen Displacement Colour change Yes Yes No Yes No No KBr added
KI added
KI added
Bromine water
KCl added
Chlorine water
Iodine water
KBr added
KCl added
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Colour change Yes Yes No Yes No No

9. Chemical Property
Ability of a substance to undergo a change that transforms it into a different substance.
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10. Chemical Equations
Use symbols and formulas to represent the identities and relative amounts of the reactants and products in a chemical reaction.
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11. Chemical Equations: Symbols
→ = yields (results of reaction)
(s) = solid
(ℓ) = liquid
(g) = gas
(aq) = aqueous (dissolved in water)
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12. Symbols ↓ = precipitate = can be used in place of (s)
↑ = gaseous state
can be used in place of (g)
A precipitate is a solid that is produced as a result of a chemical reaction in solution and that separates from the solution.
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13. Symbols ↔ or →← = reaction is reversible products re-form the
original reactants
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14. Chemical Equations: Idenities
Word Equation: reactants and products in a chemical reaction are represented by words.
carbon + oxygen yields carbon dioxide
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15. Chemical Equation: Identities
Formula Equation: reactants and products in a chemical reaction are represented by symbols or formulas
C + O2 → CO2
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16. Two Main Parts
Reactants – substance(s) that combine chemically in a chemical reaction.
Products – substance(s) formed by a chemical change.
Example:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Reactants Products
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17. Reactants & Products Mg(s) + 2HCl(aq) → MgCl2(aq) + H2 (g)
Reactants: magnesium metal
hydrochloric acid
Products: magnesium chloride
hydrogen gas
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18. Simple Chemical Reactions
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion
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19. Synthesis Two or more substances combine to form a new compound.
Example:
2C(s) + O2 (g) → 2CO(g)
Carbon + oxygen gas produces carbon monoxide
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20. Decomposition
A single compound produces two or more simpler substances.
Example ∆
2HgO(s) → 2Hg(ℓ) + O2(g)
heated mercury (II) oxide produces
liquid mercury and oxygen gas
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21. Single Replacement
One element replaces a similar element in a compound.
Example
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2 (g)
Magnesium metal plus hydrochloric acid produces magnesium chloride in solution and hydrogen gas
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22. Double Replacement
Ions of two compounds exchange places in an aqueous solution to form two new compounds.
Example
FeS(s) HCl(aq) → H2S(g) + FeCl2(aq)
Solid iron (II) sulfide plus hydrochloric acid yields hydrogen sulfide gas plus iron (II) chloride
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23. Combustion
A substance combines with oxygen, releasing a large amount of energy in the form of light and heat.
Example H2(g) + O2(g) → 2H2O(g)
Hydrogen gas burned in the oxygen
produces water
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24. Classifying Chemical Reactions
Classify the equations on the next five slides as either
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion
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25. Equation 1
2NaI + F2 (g) → 2NaF + I2(g)
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26. Equation 2
N2(g) + 3H2(g) → 2NH3(g)
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27. Equation 3
C2H6 + 5O2(g) → 3H2O(g) + 2CO2(g)
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28. Equation 4 2AgCl(aq)+BaBr2(aq) → 2AgBr(aq)+ BaCl2(aq) 2/19/2019
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29. Equation 5
2H2O(ℓ) → 2H2(g) + O2(g)
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30. Classifying Reactions
Answers
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31. Single Replacement Equation
2NaI + F2(g) → 2NaF + I2(g)
One ion, fluorine (F), exchanged places with iodine (I) in NaI.
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32. Synthesis Reaction Equation 2 N2(g) + 3H2(g) → 2NH3(g)
Nitrogen, N2, combined with hydrogen, H2, to form ammonia
Nitrogen and hydrogen are diatomic when written ALONE.
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33. Combustion Reaction Equation 3 C2H6 + 5O2(g) → 3H2O(g) + 2CO2(g)
C2H6, ethane, burned in oxygen produced water and carbon dioxide
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34. Double Replacement Reaction
Equation 4
2AgCl(aq) + BaBr2(aq) → 2AgBr(aq)+ BaCl2(aq)
Two ions, chloride (Cl-) and bromide (Br-) exchanged partners.
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35. Decomposition Reaction
Equation 5
2H2O(ℓ) → 2H2(g) O2(g)
Water, H2O broke up into hydrogen gas, H2, and oxygen gas, O2.
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36. Videos of Chemical Reactions
Copy and paste the urls below to see examples of reactions.
1. Synthesis
2. Single Replacement :
3. Double Replacement:
4. Decomposition:
5. Combustion:
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