Equilibrium and types of equilibrium
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There are two types of equilibrium: physical and chemical. Physical equilibrium occurs when a system's physical state does not change over time, such as when a solid melts at a fixed temperature. Chemical equilibrium is reached when the rates of the forward and reverse reactions are equal and the concentrations of reactants and products remain constant. The equilibrium constant (K) is a ratio of product to reactant concentrations raised to their stoichiometric coefficients that remains constant at equilibrium. K can be used to determine whether the equilibrium favors reactants or products.
![For the general reaction :
K =
[C]c[D]d
[A]a[B]b
aA (g) + bB (g) cC (g) + dD (g)](https://image.slidesharecdn.com/equilibriumandtypesofequilibrium-160429161632/85/Equilibrium-and-types-of-equilibrium-6-320.jpg)
![For an example if we take the following reaction
than Kc and Kp can be obtained as follows :
Kc =
[NO2]2
[N2O4]
N2O4 (g) ↔ 2NO2 (g)
In most cases
Kc Kp
Kp =
NO2
P2
N2O4
P](https://image.slidesharecdn.com/equilibriumandtypesofequilibrium-160429161632/85/Equilibrium-and-types-of-equilibrium-9-320.jpg)
Equilibrium and types of equilibrium
- 1. Equilibrium and types of equilibrium
- 2. Equilibrium is defined as a state in which there are no observable changes as time goes by. Types of Equilibrium : There are two types of equilibrium: 1. Physical Equilibrium 2.Chemical Equilibrium
- 3. 1.Physical Equilibrium : A physical equilibrium is a system whose physical state does not change when dynamic equilibrium is achieved. When a solid is heated it starts melting at a certain fixed temperature (melting point). At this stage even continued, the temperature does not change until the whole of solid is converted into liquid.
- 4. 2. Chemical Equilibrium : chemical equilibrium is the state in which both reactants and products are present in concentration which have no further tendency to change with time. Chemical equilibrium is achieved when: 1.) the rates of the forward and reverse reactions are equal and 2.) the concentrations of the reactants and products remain constant
- 5. Law of Mass Action- For a reversible reaction at equilibrium and constant temperature, a certain ratio of reactant and product concentrations has a constant value (K). The Equilibrium Constant (K)- A number equal to the ratio of the equilibrium concentrations of products to the equilibrium concentrations of reactants each raised to the power of its stoichiometric coefficient.
- 6. For the general reaction : K = [C]c[D]d [A]a[B]b aA (g) + bB (g) cC (g) + dD (g)
- 7. Chemical equilibrium is defined by K. The magnitude of K will tell us if the equilibrium reaction favors the reactants or the products. If K » 1……..favors products. If K « 1……..favors reactants.
- 8. Equilibrium constants can be expressed using Kc or Kp. Kc uses the concentration of reactants and products to calculate the eq. constant. Kp uses the pressure of the gaseous reactants and products to calculate the eq. constant.
- 9. For an example if we take the following reaction than Kc and Kp can be obtained as follows : Kc = [NO2]2 [N2O4] N2O4 (g) ↔ 2NO2 (g) In most cases Kc Kp Kp = NO2 P2 N2O4 P
- 10. Relationship between Kc and Kp : Kp = Kc(RT)Dn Dn = moles of gaseous products – moles of gaseous reactants = (c + d) – (a + b) aA (g) + bB (g) cC (g) + dD (g) For following reaction Relationship between Kc and Kp can be gives as under