types of chemical reactions single replacement reactions double replacement reactions combustion...

Types of Chemical Reactions

Single Replacement Reactions

Double Replacement Reactions

Combustion Reactions

Recall

Synthesis ReactionsTwo or more substances combine to form one

substance.The general form is A + X AXDecomposition ReactionsOne substance reacts to form two or more

substances. The general form is AX A+X

Single Replacement Reactions

A metal will replace a metal ion in a compound.The general form is A + BX AX + B

A nonmetal will replace a nonmetal ion in a compound.The general form is Y+BX BY + X

Single Replacement Reactions

• Examples:

– Ni + AgNO3 NiNO3 + Ag

• Nickel replaces the metallic ion Ag+ (metal replaces metal ion)

• The silver becomes free silver and the nickel becomes the nickel (II) ion.

• Ni + AgNO3 Ag + Ni(NO3)2

–Balance the equation:

–Ni + 2AgNO3 2Ag + Ni(NO3)2

Thermite Reaction

• Steve Spangler Video Thermite

Thermite Reaction

• Al + Fe2O3

• Aluminum will replace iron (III) as was seen in the video.

• Iron (III) becomes Fe and aluminum metal becomes Al3+.

• 2Al + Fe2O3 Al2O3 + 2Fe

Double Replacement Reactions

Ions of two compounds exchange places with each other.

Reactants must be two ionic compounds, in aqueous solution

The general form is AX+BY = AY + BX

Remember the Demonstration!!!!!!!!

Word - Lead (II) Nitrate + Potassium Iodide --> Potassium Nitrate + Lead Iodide

Skeletal - Pb(NO3)2 (aq) + 2KI (aq) --> 2KNO3 (aq) + PbI2 (s)

What occurred???

This is a double displacement reaction

Double ReplacementNaOH + CuSO4 The Na+ and Cu2+ switch places.Na+ combines with SO4

2- to form Na2SO4.

Cu2+ combines with OH- to form Cu(OH)2

NaOH + CuSO4 Na2SO4 + Cu(OH)2

2NaOH + CuSO4 Na2SO4 + Cu(OH)2

Double Replacement

• CuSO4 + Na2CO3

• Cu2+ combines with CO32- to form

CuCO3.

• Na+ combines with SO42- to form

Na2SO4.

• CuSO4 + Na2CO3 CuCO3 + Na2SO4

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)

2

Recognition

You need to be able to recognize which reaction is taking place

Practice Examples:• H2 + O2

• H2O

• Zn + H2SO4

• HgO

• KBr + Cl2

• AgNO3 + NaCl • Mg(OH)2 + H2SO3

Synthesis Decomposition Single Displacement Decomposition Single Displacement Double Replacement Double Replacement

Combustion Reactions• Combustion means “add Oxygen”

Normally, a compound composed of only C, H, (and maybe O) is reacted with oxygen – usually called “burning”

• If the combustion is complete, the products will be CO2 and H2O.

• If the combustion is incomplete, , the products will be CO (or possibly just C) and H2O.

Combustion ReactionWhen a substance combines with

oxygen, a combustion reaction results.The combustion reaction may also be an

example of an earlier type such as 2Mg + O2 2MgO.

The combustion reaction may be burning of a fuel.

Combustion Reactions• Combustion reactions involve

light and heat energy released.• Natural gas, propane, gasoline,

etc. are burned to produce heat energy.

• Most of these organic reactions produce water and carbon dioxide.

Combustion ReactionWhen hydrocarbon compounds CxHx are

burned in oxygen, the products are water and carbon dioxide.

CH4 + O2 CO2 + H2O

CH4 + 2O2 CO2 + 2H2O

Demonstration

Combustion Reactions

Generally combustion reactions involve the burning of a Hydrocarbon (CxHx) in Oxygen.

Other elements can also burn with Oxygen2Mg + O2 2MgO+ Energy

2H2 + O2 2H2O+ Energy (basis behind fuel cell energy)

P4 + 5O2 P4O10 + Energy (matches)

PracticeClassify each of the following as to type:

H2 + Cl2 2HClSynthesis

Ca + 2H2O Ca(OH)2 + H2

Single Displacement

Practice2CO + O2 2CO2

Synthesis and Combustion

2KClO3 2KCl + 3O2

Decomposition

PracticeFeS + 2HCl FeCl2 + H2S

Double Replacement

Zn + 2HCl ? ZnCl2+ H2

Single Displacement