Types of Chemical Reactions Chemistry Types of Chemical Reactions

Types of Chemical Reactions Many chemical reactions have defining characteristics which allow them to be classified as a type.

Types of Chemical Reactions Learning Targets: Describe the five general types of reactions. Predict the products of the five general types of reactions.

Types of Chemical Reactions The five types of chemical reactions in this unit are: Synthesis Decomposition Single Replacement Double Replacement Combustion 5 Types of Reactions Video

Synthesis Reactions Two or more substances combine to form one substance. The general form is A + X AX Example: Magnesium + oxygen  magnesium oxide 2Mg + O2  2MgO

Synthesis Reactions Synthesis reactions may also be called composition or combination reactions. Some types of synthesis reactions: Combination of elements K + Cl2  what is the product? One product will be formed

Synthesis Reactions KCl 2K + Cl2  2KCl Write the equation K + Cl2  Balance the equation: KCl 2K + Cl2  2KCl

Synthesis Reactions Examples of synthesis reactions: SO2 + H2O  H2SO3 BaO + H2O  Ba(OH)2 Na2O + CO2  Na2CO3 CaO + SO2  CaSO3

Synthesis Reactions Elements or compounds combine to form ONE product The only synthesis reactions you will be asked to determine would be the very simple ones with only 1 possible answer A + B = AB (A is positive, B is negative) E.g. K + Cl2 = KCl

Decomposition Reactions One substance reacts to form two or more substances. The general form is AX  A + X Example: Water can be decomposed by electrolysis.(don’ forget diatomic molecules) 2H2O  2H2 + O2

Decomposition Reactions Examples of Decomposition Reactions: CaCO3  CaO + CO2 H2CO3  H2O + CO2 Ca(OH)2  CaO + H2O 2KClO3  2KCl + 3O2 Zn(ClO3)2  ZnCl2 + 3O2

Decomposition Reactions Some substances can easily decompose: Ammonium hydroxide is actually ammonia gas dissolved in water. NH4OH  NH3 + H2O Some acids decompose into water and an oxide. H2SO3  H2O + SO2

Decomposition Reactions The only decomposition reactions you will be asked to determine would be the simple ones with only 1 possible answer E.g. 2H2O  2H2 + O2

Types of Chemical Reactions Single Replacement Reactions Double Replacement Reactions Combustion Reactions

Recall Synthesis Reactions Two or more substances combine to form one substance. The general form is A + X AX Decomposition Reactions One 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+ +B+X-AX + B A nonmetal(-) will replace a nonmetal ion in a compound. The general form is Y-+B+X-  BY + X

Single Replacement Reactions Examples: Ni + AgNO3  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 Thermite Video

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  2Fe + Al2O3

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

Double Replacement NaOH + CuSO4  The Na+ and Cu2+ switch places. Na+ combines with SO42- 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(aq)  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 ® Synthesis H2O ® Decomposition Zn + H2SO4 ® HgO ® KBr + Cl2 ® AgNO3 + NaCl ® Mg(OH)2 + H2SO3 ® Synthesis Decomposition Single Replacement Double Replacement

Classifying Chemical Reactions - Flintstones Video

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 Reaction When a substance combines with oxygen, a combustion reaction can result. The combustion reaction may also be an example of an earlier type such as 2Mg + O2  2MgO. An example of a combustion reaction is burning of fuel like gas or oil.

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 Reaction When hydrocarbon compounds CxHx are burned in oxygen, the products are water and carbon dioxide. CH4 + O2  CO2 + H2O CH4 + 2O2  CO2 + 2H2O

Combustion Reactions Generally combustion reactions involve the burning of a Hydrocarbon (CxHx) in Oxygen. Other elements can also burn with Oxygen 2Mg + O2  2MgO + Energy 2H2 + O2  2H2O + Energy (basis behind fuel cell energy) P4 + 5O2  P4O10 + Energy (matches)

So you want to make a product video

Practice Classify each of the following as to type: H2 + Cl2  2HCl Synthesis Ca + 2H2O  Ca(OH)2 + H2 Single replacement

Practice 2CO + O2  2CO2 2KClO3  2KCl + 3O2 Synthesis and combustion Decomposition

Practice FeS + 2HCl  FeCl2 + H2S Zn + HCl  ? Double replacement Single replacement Zn + 2HCl  ZnCl2 + H2

End of Day 2 Types of Chemical Reactions Worksheet