[Chemistry Class Notes] on Types of Reactions Experiment Pdf for Exam

Matter undergoes three different types of changes: physical changes, chemical changes, and nuclear changes. From these changes, the composition of a substance is not altered by physical changes, such as freezing and evaporation. Chemical changes, or in reactions, the formation of new substances are formed. These substances are formed when bonds are formed or broken. 

Types of Chemical Reactions Experiment

The types of chemical reaction experiment depend upon the reactivity of the chemicals. The types of reaction experiments are:

1. Combination reaction (Synthesis reaction experiment)

2. Decomposition reaction

3. Single displacement reaction experiment (Single replacement reaction)

4. Combustion reaction

Combination Reaction- 

In this reaction, two or more two molecules react (combine) and form a single new compound. This type of reaction experiment is also called a synthesis reaction experiment. One combination reaction represents the combination of two or more elements or molecules for the purpose of product formation. Synthesis reaction experiment can be represented as:

A + B → AB

Example: Formation of sodium chloride salt (NaCl) 

2 Na (s) + Cl2 (g) → 2NaCl (s) 

Reaction of elements with oxygen. Metal and non-metals react readily with the free oxygen and form oxides.

2 Mg (S) + O2 (g) → 2MgO (s)

Decomposition Reaction– 

In this type of reaction, complex compounds break into simpler ones. For this reaction, a source of energy is required to break the existing bonds of the complex compound. Decomposition reaction represents the breaking down of the complex compound bond for the formation of simpler compounds. This type of reaction can be represented as 

AB → A + B

This type of reaction occurs in the presence of light, heat, or electricity. When the binary compound is decomposed to form a product, it is called a simple decomposition reaction.  

2 HgO (s) → 2 Hg (l) + O2 (g)

In the decomposition reaction, the reactant can get converted into either elemental form or compound form. In the decomposition of calcium carbonate (CaCO3), calcium oxide and carbon dioxide molecule is formed as a product. Bases or alkalis get decomposed on heating.

2 NaOH (s) + Na2O (s) + H2O (g)

Single Displacement Reaction Experiment-

In this type of reaction one element of the reactant replaces the similar type of element of the different reactant compound. This type of reaction is also known as a single replacement reaction experiment. This type of reaction depends upon the reactivity of the elements. Highly reactive elements replace low reactive elements. Single displacement reaction experiment can be represented as:

A + BC → AC + B

Example: Mg (s) + Cu(NO3)2 (aq) → Mg(NO3)2 (aq) + Cu (s)

The above reaction represents that magnesium is more reactive than copper. Therefore, magnesium replaces copper. 

Combustion Reaction- 

Combustion reaction is a type of reaction in which reactants react with oxygen and release energy or heat in the surrounding. A combustion reaction takes place in the presence of oxygen. This type of reaction can be of two types: 

• Incomplete combustion

• Complete combustion

Organic compounds when undergoes complete combustion produces carbon dioxide, water molecules in the gaseous state, and energy. 

C3H8 (g) +5 O2 (g) → 3 CO2 (g) + 4 H2O (g)

Generally, hydrocarbons are used in combustion reactions for energy production. A combustion reaction is an exothermic reaction.

Double Displacement Reaction–

In these types of chemical reactions experiment the positive ions (cation) and negative ions (anion) exchange their position to form new compounds. Double displacement reactions generally occur in an ionic compound. Double displacement reaction is represented as:

AB + CD → AD + CB

In the above reaction, AB and CD are ionic compounds. In AB A is a cation and B is an anion. In CD C is a cation and D is an anion.

Comparison of Single Replacement Reaction Experiment and Double Displacement Reaction

In a single replacement reaction experiment, only one element replaces the other in the two reactants, depending upon the reactivity. While in a double displacement reaction reactants exchange the cation or anion of the two ionic compounds. In a single replacement reaction experiment, both elemental state and ionic state can participate. While in a double displacement reaction only ionic compounds can participate.

Did You Know?

• You may think that chemical reaction occurs only in the laboratories, but it also occurs in the human body, plants, and the environment.

• All types of chemical reactions do not occur at the same rate. Some reaction completes in a few minutes and some get completed in years.

• The rate of a chemical reaction can be altered by the addition of a catalyst.

• In physical changes, no chemical reaction occurs.

• When a single reaction completes in the series of the reaction, it is termed a chain reaction.