CBSE Class 11 - Chemistry - Chapter: Equilibrium - What are Irreversible and Reversible Reactions? (#eduvictors)(#cbse2020)(#class11Chemistry)

What are Irreversible and Reversible Reactions? 

CBSE Class 11 - Chemistry - Chapter: Equilibrium 

Q1: What is equilibrium?

Answer: It is a state in a process when two opposing processes (forward and reverse) occur simultaneously at the same rate. The free

energy change at equilibrium state is zero i.e., ΔG = 0.

Q2: What are reversible reactions? Give examples.

Answer:  Chemical reactions in which the entire amounts of reactants are converted into products are termed irreversible reactions.  

Irreversible reactions form the basis of quantitative chemical analysis such as volumetric analysis.

Examples are:

The reaction between led nitrate and potassium chromate is an irreversible reaction.

Pb(NO₃)₂ (aq)  + K₂CrO₄ (aq)   →    PbCrO₄ (s)   + 2KNO₃ (aq)

The reaction between a strong acid and strong base are irreversible.

HCl + NaOH  →  NaCl  + H₂O

Q3: What are reversible reactions? Give examples.

Answer: The reactions in which only a part of the total amount of reactants is converted into products are called reversible reactions. When molecules begin to react, the rate of the forward reaction is faster than the rate of the reverse reaction. In the chemical equations for the reversible reactions, the reactants and products are separated by the symbols (⇌).

Examples are:

Neutralisation between an acid and a base either of which or both are weak like

CH₃CHOOH + NaOH    ⇌   CH₃COONa + H₂O

Esterification reaction

CH₃CHOOH + C₂H₅OH ⇌  CH₃COOC₂H₅ + H₂O

Evaporation of water in a closed container.

H₂O (l)  ⇌ H₂O (g)

Thermal decomposition of Calcium carbonate

CaCO₃(s) ⇌ CaO(s) + CO₂(g)

Q4: Under what condition, a reversible process becomes irreversible?

Answer: If one of the products (gaseous) is allowed to escape out (i.e., in an open vessel) or the reaction results in the formation of a precipitate.

☞See also:

How to learn about Chemical Formula?
All about Names of the Chemical Elements
Mole Concept 
Discoveries In Atomic Structure
Law of Chemical Combinations
Thermodynamics

Four New Elements Added in Periodic Table
Quiz On Gases

Ch 9 - Hydrogen (Very Short Q & A)

Ch14 - Environmental Chemistry - Atmospheric Pollution (Concept Points)