Effect of increasing temperature on equilibrium constant is given by
$\log {K_2} - \log {K_1} = \dfrac{{ - \Delta H}}{{2.303R}}\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$
Then for an endothermic reaction the false statement is:
A. $\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right] = $ positive
B. $\log {K_2} > \log {K_1}$
C. $\Delta H = $ positive
D. ${K_2} > {K_1}$
Answer
638.1k+ views
Hint:This question gives the knowledge about the temperature dependent activation energy equation. Activation energy is the least amount of energy required to energize or activate atoms or molecules in order to proceed a chemical reaction.
Formula used:
The temperature dependent activation energy equation is as follows:
$\log {K_2} - \log {K_1} = \dfrac{{ - \Delta H}}{{2.303R}}\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$
Where ${K_2}$ is second rate, ${K_1}$ is the first rate, $\Delta H$ is the change in enthalpy, $R$ is the gas constant, ${T_2}$ is the final temperature and ${T_1}$ is the initial temperature.
Complete step by step answer:
Activation energy is the least amount of energy required to energize or activate atoms or molecules in order to proceed a chemical reaction. With the increase in temperature, randomness increases which means the atoms or molecules start moving faster. Therefore, with this increase in temperature the probability of molecules to move with appropriate activation energy for collision also increases.
The temperature dependent activation energy equation is as follows:
$\log {K_2} - \log {K_1} = \dfrac{{ - \Delta H}}{{2.303R}}\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$
In endothermic reactions generally absorption of heat energy takes place which means the enthalpy will be positive.
$ \Rightarrow \Delta H = $ positive
Also for endothermic reactions final temperature is higher than initial temperature which means
$ \Rightarrow {T_2} > {T_1}$
Consider the temperature change from the equation of activation energy as follows:
$ \Rightarrow \left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$
On rearrangement, we get
$ \Rightarrow \left[ {\dfrac{{{T_1} - {T_2}}}{{{T_2}{T_1}}}} \right] < 0$
This concludes that $\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$ is negative.
Consider the rate from the equation of activation energy as follows:
$ \Rightarrow \log {K_2} - \log {K_1} > 0$
On rearranging, we get
$ \Rightarrow \log {K_2} > \log {K_1}$
Hence, option $A$ is the correct option.
Note:
Always remember the concept that with the increase in temperature, randomness increases which means the atoms or molecules start moving faster. Therefore, with this increase in temperature the probability of molecules to move with appropriate activation energy for collision also increases.
Formula used:
The temperature dependent activation energy equation is as follows:
$\log {K_2} - \log {K_1} = \dfrac{{ - \Delta H}}{{2.303R}}\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$
Where ${K_2}$ is second rate, ${K_1}$ is the first rate, $\Delta H$ is the change in enthalpy, $R$ is the gas constant, ${T_2}$ is the final temperature and ${T_1}$ is the initial temperature.
Complete step by step answer:
Activation energy is the least amount of energy required to energize or activate atoms or molecules in order to proceed a chemical reaction. With the increase in temperature, randomness increases which means the atoms or molecules start moving faster. Therefore, with this increase in temperature the probability of molecules to move with appropriate activation energy for collision also increases.
The temperature dependent activation energy equation is as follows:
$\log {K_2} - \log {K_1} = \dfrac{{ - \Delta H}}{{2.303R}}\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$
In endothermic reactions generally absorption of heat energy takes place which means the enthalpy will be positive.
$ \Rightarrow \Delta H = $ positive
Also for endothermic reactions final temperature is higher than initial temperature which means
$ \Rightarrow {T_2} > {T_1}$
Consider the temperature change from the equation of activation energy as follows:
$ \Rightarrow \left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$
On rearrangement, we get
$ \Rightarrow \left[ {\dfrac{{{T_1} - {T_2}}}{{{T_2}{T_1}}}} \right] < 0$
This concludes that $\left[ {\dfrac{1}{{{T_2}}} - \dfrac{1}{{{T_1}}}} \right]$ is negative.
Consider the rate from the equation of activation energy as follows:
$ \Rightarrow \log {K_2} - \log {K_1} > 0$
On rearranging, we get
$ \Rightarrow \log {K_2} > \log {K_1}$
Hence, option $A$ is the correct option.
Note:
Always remember the concept that with the increase in temperature, randomness increases which means the atoms or molecules start moving faster. Therefore, with this increase in temperature the probability of molecules to move with appropriate activation energy for collision also increases.
Recently Updated Pages
Write structures of the following compounds i 2 Chloro3methylpentane class 11 chemistry CBSE

What is BLO What is the full form of BLO class 8 social science CBSE

Explain the Treaty of Vienna of 1815 class 10 social science CBSE

A Paragraph on Pollution in about 100-150 Words

XIX+XXX A 49 B 51 C 55 D 44 class 5 maths CBSE

If x a + bt + ct2 where x is in meters and t is in class 11 physics CBSE

Trending doubts
One Metric ton is equal to kg A 10000 B 1000 C 100 class 11 physics CBSE

Find the value of the expression given below sin 30circ class 11 maths CBSE

What do you mean by retardation What is its SI uni class 11 physics CBSE

Draw a diagram of nephron and explain its structur class 11 biology CBSE

10 examples of friction in our daily life

Difference between physical and chemical change class 11 chemistry CBSE

