
How does the equilibrium constant change with temperature?
Answer
438.6k+ views
Hint : In order to answer the question, to know how the equilibrium constant changes with temperature, we should go through both the exothermic reaction and the endothermic reaction. And we will discuss more about this topic.
Complete Step By Step Answer:
Yes, the equilibrium constant varies with the change in temperature. The equilibrium constant of an exothermic reaction decreases as the temperature decreases. However, in an endothermic reaction, the equilibrium constant increases with increase in temperature.
For an exothermic reaction $ (\Delta H\;is{\text{ }}negative) $ , $ K $ decreases with an increase in temperature.
For an endothermic reaction $ (\Delta H\;is{\text{ }}positive) $ , $ K $ increases with an increased temperature.
We can calculate the effect of changing temperature on the equilibrium constant by using the van't Hoff equation:
$ \dfrac{{d\,\ln \,K}}{{dT}} = \dfrac{{\Delta {H^\circ }}}{{R{T^2}}} $ , where $ R $ is the Ideal Gas Constant.
If we integrate the above equation from $ {T_1}\,to\,{T_2} $ , we get-
$ \ln (\dfrac{{{K_2}}}{{{K_1}}}) = \dfrac{{\Delta {H^\circ }}}{R}(\dfrac{1}{{{T_1}}} - \dfrac{1}{{{T_2}}}) $
Thus, if we know the $ \Delta {H^\circ } $ and the equilibrium constant at one temperature, we can calculate the equilibrium constant at some other temperature.
Note :
Le Chatelier's principle states that a change in temperature, pressure, or concentration of reactants in an equilibrated system will stimulate a response that partially offsets the change to establish a new equilibrium. In the case of changing temperature, adding or removing heat shifts the equilibrium.
Complete Step By Step Answer:
Yes, the equilibrium constant varies with the change in temperature. The equilibrium constant of an exothermic reaction decreases as the temperature decreases. However, in an endothermic reaction, the equilibrium constant increases with increase in temperature.
For an exothermic reaction $ (\Delta H\;is{\text{ }}negative) $ , $ K $ decreases with an increase in temperature.
For an endothermic reaction $ (\Delta H\;is{\text{ }}positive) $ , $ K $ increases with an increased temperature.
We can calculate the effect of changing temperature on the equilibrium constant by using the van't Hoff equation:
$ \dfrac{{d\,\ln \,K}}{{dT}} = \dfrac{{\Delta {H^\circ }}}{{R{T^2}}} $ , where $ R $ is the Ideal Gas Constant.
If we integrate the above equation from $ {T_1}\,to\,{T_2} $ , we get-
$ \ln (\dfrac{{{K_2}}}{{{K_1}}}) = \dfrac{{\Delta {H^\circ }}}{R}(\dfrac{1}{{{T_1}}} - \dfrac{1}{{{T_2}}}) $
Thus, if we know the $ \Delta {H^\circ } $ and the equilibrium constant at one temperature, we can calculate the equilibrium constant at some other temperature.
Note :
Le Chatelier's principle states that a change in temperature, pressure, or concentration of reactants in an equilibrated system will stimulate a response that partially offsets the change to establish a new equilibrium. In the case of changing temperature, adding or removing heat shifts the equilibrium.
Recently Updated Pages
Express the following as a fraction and simplify a class 7 maths CBSE

The length and width of a rectangle are in ratio of class 7 maths CBSE

The ratio of the income to the expenditure of a family class 7 maths CBSE

How do you write 025 million in scientific notatio class 7 maths CBSE

How do you convert 295 meters per second to kilometers class 7 maths CBSE

Write the following in Roman numerals 25819 class 7 maths CBSE

Trending doubts
State and prove Bernoullis theorem class 11 physics CBSE

What are Quantum numbers Explain the quantum number class 11 chemistry CBSE

Write the differences between monocot plants and dicot class 11 biology CBSE

1 ton equals to A 100 kg B 1000 kg C 10 kg D 10000 class 11 physics CBSE

State the laws of reflection of light

In northern hemisphere 21st March is called as A Vernal class 11 social science CBSE
