unit 7 chemical reactions types of reactions. type of reactions chemical reactions are classified...
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Unit 7 Chemical Reactions
Types of Reactions
Type of ReactionsChemical reactions are classified into five general types
Synthesis (also called combination or addition)
Decomposition Single Replacement (also called single
displacement) Double Replacement(also called double
displacement) Combustion
Synthesis (Combination) Two or more elements or simple compounds combine to form (synthesize) one product
A + B AB2Mg + O2 2MgO
2Na + Cl2 2NaCl
SO3 + H2O H2SO4
When two elements combine in synthesis, the product is a compound made of their respective ions.
Combination (Synthesis) YouTube - Reaction of Sodium & Chlorine
(with subtitles)
Synthesis (practice)• Predict the products. Write and balance
the following synthesis reaction equations.• Sodium metal reacts with chlorine gas Na(s) + Cl2(g) • Solid Magnesium reacts with fluorine gas Mg(s) + F2(g) • Aluminum metal reacts with fluorine gas Al(s) + F2(g)
Combination (Synthesis) Practice
• Predict the products. Write and balance the following synthesis reaction equations.
• Sodium metal reacts with chlorine gas 2 Na(s) + Cl2(g) 2 NaCl• Solid Magnesium reacts with fluorine gas Mg(s) + F2(g) MgF2• Aluminum metal reacts with fluorine gas 2Al(s) + 3 F2(g) 2AlF3
DecompositionOne substance is broken down (split) into two or more simpler substances.
AB A + B
2HgO 2Hg + O2
2KClO3 2KCl + 3 O2
a compound made of two elements, decomposes into those elements.
DecompositionYouTube - ammonium dichromate volcano
Decomposition Practice•Predict the products. Then, write
and balance the following decomposition reaction equations:
•Solid Lead (IV) oxide decomposes PbO2(s)
•Aluminum nitride decomposes AlN(s)
Decomposition Practice•Predict the products. Then, write
and balance the following decomposition reaction equations:
•Solid Lead (IV) oxide decomposes PbO2 (s) Pb (s) + O2 (g)
•Aluminum nitride decomposes 2AlN(s) 2 Al (s) + N2 (g)
Learning Check 1Classify the following reactions as 1) combination or 2) decomposition:
___A. H2 + Br2 2HBr
___B. Al2(CO3)3 Al2O3 + 3CO2
___C. 4 Al + 3C Al4C3
Solution 1Classify the following reactions as 1) combination or 2) decomposition:
_1_A. H2 + Br2 2HBr
_2_B. Al2(CO3)3 Al2O3 + 3CO2
_1_C. 4 Al + 3C Al4C3
Single Replacement (Displacement)One element takes the place of an element in a reacting compound.
A + BC AC + B
Zn + 2HCl ZnCl2 + H2
Fe + CuSO4 FeSO4 +
Cu
A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-).
Whether one metal will displace another metal from a compound depends on the relative reactivity's of the two metals.
Single Replacement (Displacement) Practice
YouTube - Thermite reaction
Single Replacement Displacement)
The activity series of metals lists metals in order of decreasing reactivity.
A metal will replace any metal listed below.
Lithium
Potassium
Calcium
Sodium
Magnesium
Aluminum
Zinc
Iron
Lead
Hydrogen
Copper
Mercury
silver
Single Replacement (Displacement) Practice
•Sodium chloride solid reacts with fluorine gas
NaCl(s) + F2(g)
•Aluminum metal reacts with aqueous copper (II) nitrate
Al(s)+ Cu(NO3)2(aq)
Single Replacement (Displacement) Practice
•Sodium chloride solid reacts with fluorine gas
2NaCl(s) + F2(g) 2 NaF(s) + Cl2(g)
Note that fluorine (nonmetal) replaces chlorine (nonmetal) in the compound
•Aluminum metal reacts with aqueous copper (II) nitrate
2 Al(s)+ 3Cu(NO3)2(aq) 3Cu(s) + 2 Al(NO3)3
Double Replacement (Displacement)
Two elements in reactants take the place of each other
AB + CD AD + CB
AgNO3 + NaCl AgCl +
NaNO3
ZnS + 2HCl ZnCl2 +
H2S
Double Replacement (Displacement)
YouTube - Double Replacement Reactions
• Think about it like “foil”ing in algebra, first and last ions go together ; inside ions go together
• Example:
AgNO3(aq) + NaCl(s) AgCl(s) + NaNO3(aq)
• Another example:
K2SO4(aq) + Ba(NO3)2(aq) KNO3(aq) + BaSO4(s)
Classify the following reactions as 1) single replacement 2) double replacement
__A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2
__B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3
__C. 3C + Fe2O3 2Fe + 3CO
Classify the following reactions as 1) single replacement 2) double replacement
1_A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2
2_B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3
1_C. 3C + Fe2O3 2Fe + 3CO
Double Replacement Practice
• Predict the products. Balance the equation
1. HCl(aq) + AgNO3(aq)
2. CaCl2(aq) + Na3PO4(aq)
Double Replacement Practice
• Predict the products. Balance the equation
1. HCl(aq) + AgNO3(aq) HNO3 + AgCl
2. CaCl2(aq) + Na3PO4(aq) Ca3(PO4)2 + NaCl
CombustionA reaction in which a hydrocarbon (compound made up of H and C) reacts with oxygen and the products are carbon dioxide and water
CH4 + 2O2 CO2 + 2H2O
C3H8 + 5O2 3CO2 + 4H2O
Combustion•Combustion reactions
occur when a hydrocarbon reacts with oxygen gas.
•This is also called burning!!! In order to burn something you need the 3 things in the “fire triangle”:1) A Fuel (hydrocarbon)2) Oxygen to burn it with3) Something to ignite the reaction (spark)
Products in combustion are ALWAYS carbon dioxide and water. (although incomplete burning does cause some by-products like carbon monoxide)
Combustion PracticeComplete and Balance the combustion
equation
___C5H12 + ___O2
Combustion PracticeBalance the combustion equation
__C5H12 + _8_O2 5CO2 + _6H2O
Unit 8 Chemical Reactions
Types of Reactions
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