write the types of chemical reactions? explain with example.
Answers
Types of Chemical Reactions
There are different types of chemical reactions and more than one way of classifying them. Here are some common reaction types:
1. Oxidation-Reduction or Redox Reaction
Redox (short for reduction-oxidation reaction) is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a reduction process and a complementary oxidation process, two key concepts involved with electron transfer processes.
The chemical species from which the electron is stripped is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. It can be explained in simple terms:
Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion.
Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion.
The reaction that occurs when In which I2 is reduced to I– and S2O32- (thiosulfate anion) is oxidized to S4O62- provides an example of a redox reaction:
2 S2O32−(aq) + I2(aq) → S4O62−(aq) + 2 I−(aq)
2. Direct Combination or Synthesis Reaction
In a synthesis reaction, two or more chemical species combine to form a more complex product.
A + B → AB
The combination of iron an sulfur to form iron (II) sulfide is an example of a synthesis reaction:
8 Fe + S8 → 8 FeS
3. Chemical Decomposition or Analysis Reaction
In a decomposition reaction, a compound is broken into smaller chemical species.
AB → A + B
The electrolysis of water into oxygen and hydrogen gas is an example of a decomposition reaction:
2 H2O → 2 H2 + O2
4. Single Displacement or Substitution Reaction
Substitution reaction (also known as single displacement reaction or single substitution reaction) is a chemical reaction during which one functional group in a chemical compound is replaced by another functional group.
A good example of a substitution reaction is halogenation. When chlorine gas (Cl-Cl) is irradiated, some of the molecules are split into two chlorine radicals (Cl.) whose free electrons are strongly nucleophilic. One of them breaks a weak C-H covalent bond and grabs the liberated proton to form the electrically neutral H-Cl. The other radical reforms a covalent bond with the CH3. to form CH3Cl (methyl chloride).
Substitution reaction : chlorination of methane
5. Metathesis or Double Displacement Reaction
In a double displacement or metathesis reaction two compounds exchange bonds or ions in order to form different compounds.
AB + CD → AD + CB
An example of a double displacement reaction occurs between sodium chloride and silver nitrate to form sodium nitrate and silver chloride.
NaCl(aq) + AgNO3(aq) → NaNO3(aq) + AgCl(s)
Direct Combination or Synthesis Reaction. ...
Chemical Decomposition or Analysis Reaction. ...
Single Displacement or Substitution Reaction. ...
Metathesis or Double Displacement Reaction. ...
Acid-Base Reaction. ...
Combustion. ...
Isomerization.