Equilibrium

Question 1

Define equilibrium

Answer 1

Equilibrium is the state of process in which properties like temperature and pressure, concentration of system, etc. do not show any change with the passage of time

Question 2

Classification of chemical reaction

Answer 2

• Chemical reactions which proceed nearly to completion, and only negligible amount of reactants are left.
• Chemical reactions in which only small amount of products are formed, and most of the reactants remain unchanged.
• reactions in which concentration of reactants and products are comparable and system reaches equilibrium.

Question 3

• Characteristics of chemical equilibrium

Answer 3

• Chemical reactions are molecular in nature
• reactions can occur in forward and backward reactions. Such that rate of a reaction is equal to a rate of backward reaction.
• variables like temperature pressure and concentration do not change the time.
• equilibrium is dynamic in nature( System is moving constantly). but reaction occurs to be in a standstill.
• The system should be a closed system.
• Chemical equilibrium can be attained from either side
• catalyst do not alter equilibrium, but only increases the rate of reaction

Question 4

Law of mass action

Answer 4

According to law of mass action, the rate of chemical reactionary any particular temperature is proportional to the product of molar concentration of the reactants with each concentration term raised to the power equal to the number of molecules of the respective reactants, taking part in the reaction

R @ to[A]a [B]b

Question 5

As a convention…

Answer 5

As a convention, only concentration of gaseous, reactants, and products or reactants and the products. In aqueous form need to be considered.
- concentration of solids and liquids are taken as unity.

Question 6

What happens if the equilibrium constant of gaseous, reactants and products are considered?

Answer 6

If equilibrium, constant of gaseous, reactants and products are considered, it is rather easy to measure the pressure and hence equilibrium. Constant is expressed in terms of pressure.

Question 7

Relation between Kp and Kc

Answer 7

Kp= Kc (RT) ^( delta ng)

1. Delta ng =0, Kp=Kc
2. Delta ng<0. Kp<Kc
3. Delta ng>0, Kp>Kc

Question 8

Types of equilibrium

Answer 8

• homogeneous equilibrium; those reactions in which reactants and products are in the same phase.
• heterogeneous equilibrium, those reactions in which reactants and products are not in the same phase.

Question 9

Applications of equilibrium, constant

Answer 9

• predicting the extent of a reaction(Kc)
  (Extent :How much reactants are converted to products)
• The numerical value of equilibrium constant indicates the extent of the reaction.
  (It does not tell us the rate at which the reaction was achieved. A higher value of K suggests the concentration of product is high.)

Question 10

Describe the reaction quotient.

Answer 10

• The reaction question helps in predicting the direction of reaction
• The reaction quotient is a measure of the relative amount of products and reactants present in the reaction at a given time.
• it is same as Kc but the value fluctuates as system reacts. Kc’s value is fixed but Q has multiple values