Types of Chemical Reaction, Examples, Examples, Examples - Coggle Diagram
Types of Chemical Reaction
Reactions in which two or more reactants combine to form one product are called
A + B ⇨ AB
When carbon is burnt in oxygen (air), carbon dioxide is formed. In this reaction, carbon is combined with oxygen.
C + O2 ⇨ CO2
Carbon + Oxygen ⇨ Carbon dioxide
When magnesium is burnt in air (oxygen), magnesium oxide is formed. In this reaction, magnesium is combined with oxygen.
Mg + O2 ⇨ 2MgO
Magnesium + Oxygen ⇨ Magnesium oxide
When hydrogen reacts with chlorine, hydrogen chloride is formed.
H2 + Cl2 ⇨ 2HCl
Hydrogen + Chlorine ⇨ Hydrogen chloride
Reactions in which one compound decomposes in two or more compounds or element are known as DECOMPOSITION REACTION. Decomposition reaction is just opposite of combination reaction.
AB ⇨ A + B
When calcium carbonate is heated, it decomposes into calcium oxide and carbon dioxide
CaCO3 ⇨ CaO + CO2
Calcium carbonate ⇨ Calcium oxide + Carbon dioxide
Reactions in which compounds decompose into simpler compounds because of passing of electricity, are known as Electrolytic Decomposition.
Example: When electricity is passed in water, it decomposes into hydrogen and oxygen.
2H2O(l) --> 2H2(g) + O2(g)
Photolysis or Photo Decomposition Reaction
Reactions in which a compound decomposes because of sunlight are known as Photolysis or Photo Decomposition Reaction.
Example: When silver chloride is put in sunlight, it decomposes into silver metal and chlorine gas.
2AgCl(s) (white) Sunlight−→−−−−− 2Ag(s) (grey) + Cl2(g)
The decomposition of a substance on heating is known as Thermal Decomposition.
Example: 2Pb(NO3)2(s) heat−→− 2PbO(s) + 4NO2(g) + O2(g)
When ferric hydroxide is heated, it decomposes into ferric oxide and water
2Fe(OH)3 ⇨ Fe2O3 + 3H2O
Ferric hydroxide ⇨ Ferric oxide + Water
When lead nitrate is heated, it decomposes into lead oxide, nitrogen dioxide and oxygen.
2Pb(NO3)2 ⇨ 2PbO + 4NO2 + O2
Lead nitrate ⇨ Lead oxide + Nitrogen oxide + Oxygen
3. Displacement Reaction
The chemical reactions in which a more reactive element displaces a less reactive element from a compound is known as Displacement Reactions. Displacement reactions are also known as Substitution Reaction or Single Displacement/ replacement reactions.
A + BC → AC + B
When zinc reacts with copper sulphate, it forms zinc sulphate and copper metal.
Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)
When zinc reacts with hydrochloric acid, it gives hydrogen gas and zinc chloride.
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
When silver metal is dipped in copper nitrate, no reaction takes place because silver metal is less reactive than copper.
Ag + Cu(NO3 )2 ⇨ No reaction takes place
A combustion reaction is a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat. Combustion reactions must involve O2 as one reactant. The combustion of hydrogen gas produces water vapor
Combustion of methane.
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)
Combustion of methanol (also known as wood alcohol)
2CH3OH(g) + 3O2(g) → 2CO2(g) + 4H2O(g)
4.Double Displacement [Reaction]
Reactions in which ions are exchanged between two reactants forming new compounds are called Double Displacement Reactions.
AB + CD → AC + BD
When the solution of barium chloride reacts with the solution of sodium sulphate, white precipitate of barium sulphate is formed along with sodium chloride.
BaCl2(aq) + Na2SO4(aq) → BaSO4(s) (Precipitate) + 2NaCl(aq)
When sodium hydroxide (a base) reacts with hydrochloric acid, sodium chloride and water are formed.
NaOH + HCl ⇨ NaCl + H2O
The reaction between silver nitrate and sodium chloride is a double displacement reaction. The silver trades its nitrite ion for the sodium's chloride ion, causing the sodium to pick up the nitrate anion.
AgNO3 + NaCl → AgCl + NaNO3
A neutralization reaction is the reaction of an acid and a base.
HX + BOH --> BX + HOH
Acid Base Salt Water
A neutralization reaction produces a salt and water.
H2SO4 (aq) + 2 KOH (aq) --> K2SO4 (aq) + 2 H2O (l)
The expected products are water and barium nitrate, so the initial chemical reaction is
HNO3(aq) + Ba(OH)2(aq) → H2O(ℓ) + Ba(NO3)2(aq)
To balance the equation, we need to realize that there will be two H2O molecules, so two HNO3 molecules are required
2HNO3(aq) + Ba(OH)2(aq) → 2H2O(ℓ) + Ba(NO3)2(aq)
This chemical equation is now balanced.
The expected products are water and calcium phosphate, so the initial chemical equation is
H3PO4(aq) + Ca(OH)2(aq) → H2O(ℓ) + Ca3(PO4)2(s)
According to the solubility rules, Ca3(PO4)2 is insoluble, so it has an (s) phase label. To balance this equation, we need two phosphate ions and three calcium ions; we end up with six water molecules to balance the equation
2H3PO4(aq) + 3Ca(OH)2(aq) → 6H2O(ℓ) + Ca3(PO4)2(s)
This chemical equation is now balanced.
The products of the neutralization reaction will be water and calcium oxalate
H2C2O4(s) + Ca(OH)2(s) → 2H2O(ℓ) + CaC2O4(s)
Because nothing is dissolved, there are no substances to separate into ions, so the net ionic equation is the equation of the three solids and one liquid.
4H+(aq) + Ti(OH)4(s) → 4H2O(ℓ) + Ti4+(aq)