types of chemical reactions -...
TRANSCRIPT
Types of chemical reactions
What is a chemical reaction?Recall…A chemical reaction: A process in which newsubstances with new properties are formed
The original substances present are called REACTANTS.
Reactants undergo a chemical change in a chemical
reaction.
The new substances formed in a chemical reaction arecalled PRODUCTS
Chemical ReactionsFive Types of Chemical Reactions:
5. Combustion
2. Decomposition
3. Single Displacement
4. Double Displacement
1. Synthesis
Evidence that a chemical reaction has taken place?
Color/Odor Change
Difficult to reverse
Release/Absorption of Energy (heat)
Formation of a gas or solid
1. Synthesis Reactions
Combination of two or more simple substances combining to form one more complex substance.
General Form: A + B AB
+
Mg(s) + O2(g) 22
Synthesis of Magnesium Oxide
C(s) + O2(g)
S(s) + O2(g)
Synthesis Reactions:
Other Examples
MgO
CO2(g)
SO2(g)
PracticePredict the products.
Na(s) + Cl2(g)
Mg(s) + F2(g)
Al(s) + F2(g)
NaCl(s)
MgF2(s)
AlF3(s)
22
2 3 2
• Now, balance them.
2. Decomposition Reactions
Breaking down large, complex molecules or ionic compounds into smaller, simpler entities.
General Form: AB A + B
+
Ex. Decomposition Reaction
Decomposition of Hydrogen Peroxide
2 2
Predict the products.
Fe2O3(s)
NaCl(s)
CaF2(s)
H2O2(l)O2(g) + H2O(l)
3. Single Displacement
Reaction of an element with a compound that produces a new element and new compound.
A + BC AC + B
3. Single DisplacementExample: Zn + CuCl2
ZnClClCu +
General: AB + C AC + B
ClClZn Cu+
Single Displacement of Zinc and Chlorine
Zn(s) + HCl(aq) ZnCl2(aq) + H2(g)2
Zinc chloride and hydrogen gas
form in this single displacement
reaction
Ex. Single Replacement Reaction
Single Replacement Reactions
Write and balance the following single replacement reaction equation:
• K(s) + HCl(aq)
• NaCl(s) + F2(g)
• Al(s)+ Cu(NO3)2(aq)
2
Cu(s)+ Al(NO3)3(aq)232
2NaF(s) + Cl2(g)
3
KCl(s) + H2(g)2 22
Examples2KBr (aq) + Cl2 (aq)
CuSO4 (aq) + Zn (s)
Mg (s) + 2HCl (aq)
4. Double Displacement
Reaction of two compounds, where the positiveand negative ions in their respective compounds switch places to form two new compounds. This can only happen with ionic compounds
AB + CD AD + CB
Double Displacement
A double displacement reaction only occurs if one of the following three results are seen:
a precipitate is formed (check solubility rules)
a gas is produced
a change of pH occurs (a neutralization reaction)
4. Double displacement
Example: MgO + CaS
General: AB + CD AD + CB
SO
Mg Ca+
OS
Mg Ca+
Double Replacement ReactionsThink about it like “foil”ing in algebra, first and last ions go together + inside ions go together
Example 1
AgNO3(aq) + NaCl(s) AgCl(s) + NaNO3(aq)
2
Example 2
K2SO4(aq) + Ba(NO3)2(aq) KNO3(aq) + BaSO4(s)
Double Displacement Reaction
Predict the products of the following Double Displacement Reactions
Pb(NO3)2(aq) + KI(aq) 22
AgNO3(aq) + NaCl(aq)
Ni(NO3)2 (aq) + NaOH(aq)2
PbI2(s) + KNO3(aq)
AgCl(s) + NaNO3(aq)
Ni(OH) 2(s) + NaNO3(aq)
Practice
1. HCl(aq) + AgNO3(aq)
2. CaCl2(aq) + Na3PO4(aq)
3. Pb(NO3)2(aq) + BaCl2(aq)
4. FeCl3(aq) + NaOH(aq)
5. H2SO4(aq) + NaOH(aq)
6. KOH(aq) + CuSO4(aq)
Predict the products:
More commonly known as burning
5. Combustion Reactions
Easily identified (release of heat)
Heat Fuel
For combustion 3 things need to be present:
Oxygen
5. Combustion Reactions
Sulphur (in gasoline):
S(s) + O2(g) SO2(g) + Heat
2 H2(l) + O2(l) 2 H2O(g) + Heat
Rocket Fuel:
Hydrocarbons (Eg: methane):CH4(g) + O2(g) CO2(g) + H2O (g)
Mixed PracticeState the type of the following reactions & predict the products.
1. BaCl2 + H2SO4
2. C6H12 + O2
3. Zn + CuSO4
4. Cs + Br2
5. FeCO3