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Types of Chemical Types of Chemical ReactionsReactions
Writing Chemical ReactionsWriting Chemical Reactions
Types of ReactionsTypes of Reactions
Many chemical Many chemical reactions have reactions have defining defining characteristics characteristics which allow which allow them to be them to be classified as to classified as to type.type.
Types of Chemical Types of Chemical ReactionsReactions
The five types of chemical reactions The five types of chemical reactions in this unit are:in this unit are: CombinationCombination DecompositionDecomposition Single ReplacementSingle Replacement Double ReplacementDouble Replacement CombustionCombustion
Combination ReactionsCombination Reactions
Two or more substances combine to Two or more substances combine to form form one substanceone substance.. The general form is A + X The general form is A + X AXAX
Example:Example: Magnesium + oxygen Magnesium + oxygen
magnesium oxidemagnesium oxide 2Mg + O2Mg + O22 2MgO 2MgO
Magnesium + OxygenMagnesium + Oxygen
Combination ReactionsCombination Reactions
Combination reactions may also be Combination reactions may also be called called compositioncomposition or or synthesis synthesis reactionsreactions..
Some types of combination reactions:Some types of combination reactions: Combination of elementsCombination of elements
K + ClK + Cl22 One product will be formedOne product will be formed
Combination ReactionsCombination Reactions
K + ClK + Cl22
Write the ions: KWrite the ions: K++ Cl Cl--
Balance the charges: KClBalance the charges: KCl
Balance the equation: Balance the equation: 22K + ClK + Cl2 2 22KClKCl
Combination ReactionsCombination Reactions
Some types of combination Some types of combination reactions:reactions: Oxide + water Oxide + water
Nonmetal oxide + water Nonmetal oxide + water acid acidSOSO22 + H + H22O O H H22SOSO33
Metal oxide + water Metal oxide + water base baseBaO + HBaO + H22O O Ba(OH) Ba(OH)22
Combination ReactionsCombination Reactions
Some types of combination Some types of combination reactions:reactions: Metal oxides + nonmetal Metal oxides + nonmetal
oxidesoxidesNaNa22O + COO + CO22 Na Na22COCO33
CaO + SOCaO + SO2 2 CaSO CaSO33
Decomposition Decomposition ReactionsReactions
One substance reacts to form two or One substance reacts to form two or more substances. more substances. The general form is AX The general form is AX A + X A + X
Example:Example: Water can be decomposed by Water can be decomposed by
electrolysis.electrolysis. 2H2H22O O 2H 2H22 + O + O22
Electrolysis of WaterElectrolysis of Water
Decomposition Decomposition ReactionsReactions
Types of Decomposition Reactions:Types of Decomposition Reactions: Decomposition of carbonatesDecomposition of carbonates
When heated, some When heated, some carbonatescarbonates break down to form an break down to form an oxideoxide and and carbon dioxidecarbon dioxide..
CaCOCaCO33 CaO + CO CaO + CO22
HH22COCO33 H H22O + COO + CO22
Decomposition Decomposition ReactionsReactions
Types of decomposition reactions:Types of decomposition reactions: Some Some metal hydroxidesmetal hydroxides decompose decompose
into into oxidesoxides and and waterwater when heated. when heated.Ca(OH)Ca(OH)22 CaO + H CaO + H22OO
Note that this is the reverse of a Note that this is the reverse of a similar combination reaction.similar combination reaction.
Decomposition Decomposition ReactionsReactions
Types of decomposition reactions:Types of decomposition reactions: Metal chloratesMetal chlorates decompose into decompose into
chlorideschlorides and and oxygenoxygen when heated. when heated.2KClO2KClO33 2KCl + 3O 2KCl + 3O22
Zn(ClOZn(ClO33))22 ZnCl ZnCl22 + 3O + 3O22
Some of these reactions are used in Some of these reactions are used in explosives.explosives.
Decomposition Decomposition ReactionsReactions
Some substances can easily Some substances can easily decompose:decompose: Ammonium hydroxide is actually Ammonium hydroxide is actually
ammonia gas dissolved in water.ammonia gas dissolved in water.NHNH44OH OH NH NH33 + H + H22OO
Some acids decompose into water Some acids decompose into water and an oxide.and an oxide.HH22SOSO33 H H22O + SOO + SO22
Decomposition Decomposition ReactionsReactions
Some decomposition reactions Some decomposition reactions are difficult to predict.are difficult to predict.
The decomposition of nitrogen The decomposition of nitrogen triiodide, NItriiodide, NI33, is an example of an , is an example of an interesting decomposition interesting decomposition reaction.reaction.
Nitrogen triiodideNitrogen triiodide
Single Replacement Single Replacement ReactionsReactions
A metal will replace a metal ion in a A metal will replace a metal ion in a compound.compound. The general form is A + BX The general form is A + BX AX + B AX + B
A nonmetal will replace a nonmetal A nonmetal will replace a nonmetal ion in a compound.ion in a compound. The general form is Y + BX The general form is Y + BX BY + X BY + X
Single Replacement Single Replacement ReactionsReactions
Examples:Examples: Ni + AgNONi + AgNO33
Nickel replaces the metallic ion AgNickel replaces the metallic ion Ag++.. The silver becomes free silver and the The silver becomes free silver and the
nickel becomes the nickel(II) ion.nickel becomes the nickel(II) ion. Ni + AgNONi + AgNO33 Ag + Ni(NO Ag + Ni(NO33))22
Balance the equation:Balance the equation: Ni + 2AgNONi + 2AgNO33 2Ag + Ni(NO 2Ag + Ni(NO33))
Metal TreeMetal Tree
Single Replacement Single Replacement ReactionsReactions
Not all single replacement reactions Not all single replacement reactions that can be written actually happen. that can be written actually happen.
The metal must be more active than The metal must be more active than the metal ion.the metal ion.
Aluminum is more active than iron in Aluminum is more active than iron in Al + FeAl + Fe22OO33 in the following reaction: in the following reaction:
Thermite ReactionThermite Reaction
Thermite ReactionThermite Reaction
Al + FeAl + Fe22OO33 Aluminum will replace iron(III) as Aluminum will replace iron(III) as
was seen in the video.was seen in the video. Iron(III) becomes Fe and Iron(III) becomes Fe and
aluminum metal becomes Alaluminum metal becomes Al3+3+.. 22Al + FeAl + Fe22OO33 22Fe + AlFe + Al22OO33
Single Replacement Single Replacement ReactionsReactions
An active nonmetal can replace a An active nonmetal can replace a less active nonmetal.less active nonmetal. The halogen (FThe halogen (F22, Cl, Cl22, Br, Br22, I, I22) )
reactions are good examples.reactions are good examples. FF22 is the most active and I is the most active and I22 is is
the least.the least.ClCl22 +2 NaI +2 NaI 2 NaCl + I 2 NaCl + I22
Double Replacement Double Replacement ReactionsReactions
Ions of two compounds exchange Ions of two compounds exchange places with each other.places with each other. The general form is AX + BY The general form is AX + BY
AY + BXAY + BX
MetathesisMetathesis is an alternate name is an alternate name for double replacement reactions.for double replacement reactions.
NaOH + CuSONaOH + CuSO44
Double ReplacementDouble Replacement
NaOH + CuSONaOH + CuSO44 The NaThe Na++ and Cu and Cu2+2+ switch places. switch places. NaNa++ combines with SO combines with SO44
2-2- to form Na to form Na22SOSO4.4.
CuCu2+2+ combines with OH combines with OH-- to form Cu(OH) to form Cu(OH)22
NaOH + CuSONaOH + CuSO44 Na Na22SOSO44 + Cu(OH) + Cu(OH)22
22NaOH + CuSONaOH + CuSO44 Na Na22SOSO44 + Cu(OH) + Cu(OH)22
CuSOCuSO44 + Na + Na22COCO33
Double ReplacementDouble Replacement
CuSOCuSO44 + Na + Na22COCO33 CuCu2+ 2+ combines with COcombines with CO33
2-2- to form to form CuCOCuCO33..
NaNa++ combines with SO combines with SO442-2- to form to form
NaNa22SOSO44.. CuSOCuSO44 + Na + Na22COCO33 CuCO CuCO33 + Na + Na22SOSO44
NaNa22COCO33 + HCl + HCl
Double ReplacementDouble Replacement
NaNa22COCO33 + HCl + HCl Notice that gas bubbles were Notice that gas bubbles were
produced rather than a produced rather than a precipitate.precipitate.
What was the gas?What was the gas? Write the double replacement Write the double replacement
reaction first.reaction first.
Double ReplacementDouble Replacement
NaNa22COCO33 + HCl + HCl NaNa++ combines with Cl combines with Cl-- to form NaCl. to form NaCl. HH++ combines with CO combines with CO33
2-2- to form H to form H22COCO33.. NaNa22COCO33 + 2HCl + 2HCl 2NaCl + H 2NaCl + H22COCO33
HH22COCO33 breaks up into H breaks up into H22O and COO and CO22..
Double ReplacementDouble Replacement
The gas formed was carbon dioxide.The gas formed was carbon dioxide. The final balanced reaction is: The final balanced reaction is:
NaNa22COCO3 3 + HCl + HCl NaCl + H NaCl + H22O + COO + CO22.. Balance the equation.Balance the equation. NaNa22COCO33 + 2HCl + 2HCl 2NaCl + H 2NaCl + H22O + COO + CO22
Combustion ReactionCombustion Reaction When a substance combines with When a substance combines with
oxygen, a combustion reaction oxygen, a combustion reaction results.results.
The combustion reaction may also The combustion reaction may also be an example of an earlier type be an example of an earlier type such as 2Mg + Osuch as 2Mg + O22 2MgO. 2MgO.
The combustion reaction may be The combustion reaction may be burning of a fuel.burning of a fuel.
Combustion ReactionCombustion Reaction
Methane, CHMethane, CH44, is natural gas., is natural gas. When hydrocarbon compounds are When hydrocarbon compounds are
burned in oxygen, the products burned in oxygen, the products are water and carbon dioxide.are water and carbon dioxide.
CHCH44 + O + O22 CO CO22 + H + H22OO CHCH44 + 2O + 2O22 CO CO22 + 2H + 2H22OO
Combustion ReactionsCombustion Reactions
Combustion reactions involve light Combustion reactions involve light and heat energy released.and heat energy released.
Natural gas, propane, gasoline, etc. Natural gas, propane, gasoline, etc. are burned to produce heat energy.are burned to produce heat energy.
Most of these organic reactions Most of these organic reactions produce water and carbon dioxide.produce water and carbon dioxide.
PracticePractice Classify each of the following as to Classify each of the following as to
type:type:
HH22 + Cl + Cl22 2HCl 2HCl CombinationCombination
Ca + 2HCa + 2H22O O Ca(OH) Ca(OH)22 + H + H22
Single replacementSingle replacement
PracticePractice
2CO + O2CO + O22 2CO 2CO22
Combination and combustionCombination and combustion
2KClO2KClO33 2KCl + 3O 2KCl + 3O22
DecompositionDecomposition
PracticePractice
FeS + 2HCl FeS + 2HCl FeCl FeCl22 + H + H22SS Double replacementDouble replacement
Zn + HCl Zn + HCl ? ? Single replacementSingle replacement Zn + 2HCl Zn + 2HCl ZnCl ZnCl22 + H + H22
Types of Chemical Types of Chemical ReactionsReactions
Read Chapter 8-2Read Chapter 8-2
Review nomenclatureReview nomenclature
Do all of the practice exercises Do all of the practice exercises given in class.given in class.