Respuesta :
The question is incomplete, here is the complete question:
Use Le Châtelier's principle to predict how the equilibrium for the weak base methylamine responds to the indicated changes.
[tex]CH_3NH_2(aq.)+H_2O(l)\rightleftharpoons CH_3NH_3^+(aq.)+OH^-(aq.);\Delta H^o_{rxn}=103kJ/mol[/tex]
1) adding KOH
2) Increasing the temperature
Answer:
For 1: The reaction will shift in left direction that is towards the reactants.
For 2: The reaction will shift in right direction that is towards the product.
Explanation:
For the given chemical equation:
[tex]CH_3NH_2(aq.)+H_2O(l)\rightleftharpoons CH_3NH_3^+(aq.)+OH^-(aq);\Delta H^o_{rxn}=103kJ/mol[/tex]
We are given:
[tex]\Delta H^o_{rxn}=103kJ/mol[/tex]
As, enthalpy of the reaction is positive. So, it is an endothermic reaction.
For an endothermic reaction, heat is getting absorbed during a chemical reaction and is written on the reactant side.
[tex]A+\text{heat}\rightleftharpoons B[/tex]
Any change in the equilibrium is studied on the basis of Le-Chatelier's principle. This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.
- For 1: Adding KOH
As, hydroxide ions are present on the product side of the reaction. So, when more hydroxide ion is added, the concentration of hydroxide ion increases on the product side.
According to Le-Chatelier's principle, to minimize the effect, the equilibrium will shift in the direction where hydroxide ion concentration decreases, which is to the reactant side.
Hence, the reaction will shift in left direction that is towards the reactants.
- For 2: Increasing the temperature
As, heat is getting absorbed during a chemical reaction. This means that temperature is getting increased on the reactant side. If the temperature in the equilibrium is increased, the equilibrium will shift in the direction where, temperature is getting decreased.
Hence, the reaction will shift in right direction that is towards the product.
In the first case, the reaction will shift in the left towards the reactants and in the second case, the reaction will shift towards the product or the right side.
What is Le Principle?
Le principle states the change in the position of the equilibrium shifts due to disturbances in the dynamic equilibrium of a reaction.
The chemical reaction can be shown as:
[tex]\rm CH_{3}NH_{2} + H_{2}O \leftrightharpoons CH_{3}NH_{3}^{+} + OH^{-}, \Delta H_{rxn} = 103 kJ/mol[/tex]
From the reaction, it can be said that the reaction is endothermic as the value of the reaction is positive.
In the first case when potassium hydroxide is added then the reaction shift towards the reactant side on the left.
Hydroxide is present on the right side that is a product, so when the KOH is added then the concentration of the hydroxide ion increases.
So in order to minimize the equilibrium disturbance the reaction shift in the direction of the reactant so the concentration of the hydroxide can be decreased.
In the second case, when the temperature is increased then the reaction shift towards the product side on the right of the reaction because the heat gets absorbed in the reaction.
When the temperature in the equilibrium is increased then the reaction shifts towards the side where the temperature is low and hence towards the product.
Therefore, in the first case, the reaction shifts in the left and then in the second case in the right direction.
Learn more about Le principle here:
https://brainly.com/question/2142998
