Chemical equilibrium
The concept of Dynamic Equilibrium
The equilibrium reaction is a reaction in which the reaction product (product) can react again to form the original substances (reactants). So the reaction goes both ways (reversible):
At the reaction rate to the right = the reaction rate to the left
How can we know that a back and forth reaction has reached equilibrium?
When equilibrium is reached the amount of the substances both reactants and products no longer changes. The amount of the substance is proportional to mole and concentration so that when the equilibrium of moles and concentrations of the substances remain.
Characteristic of equilibrium reaction:
"Substances of the left side (reactants) are never exhausted"
In the event of equilibrium, the price of equilibrium constant (Kc) can be determined. The value is determined by using the ratio of the concentrations of the substances when the equilibrium is reached.
From the form of the above equation can be concluded:
If nikai K> 1 then the result / product generated a lot
If nikai K <1 then the result / product produced a little
FACTORS AFFECTING CHEMICAL REACTIONS OF CHEMICALS
1. Factor of Concentration Change
Based on the Le Chatelier Principle, if the reaction or reaction product concentration changes, the equilibrium will drift to reduce the effect of concentration changes that occur until new equilibrium is obtained.
There are two ways to change the concentration of substances, namely:
A. Increase / decrease the concentration of reagents or reaction products
If the concentration of reagents is increased, then the equilibrium will shift to the right. Conversely, if the reagent concentration is lowered, the reagent concentration will shift to the left
If the concentration of the reaction product is increased, then the equilibrium will shift to the left. Conversely, if the concentration of the reaction product is lowered, then the equilibrium will shift to the right.
B. Dilution
Dilution (addition of a liquid solvent such as water) will decrease the concentration of reagents of the solutes in it. For the following equilibrium reaction:
AA + bB <-> cC + dD
Dilution will only shift equilibrium if:
Total mole of reagent ≠ Total mole of reaction product
2. Pressure and Volume Changes
The effect of pressure change on reaction equilibrium applies only to reaction systems involving gas. Under Le Chatelier Principle, if the pressure of a reaction system is changed, the equilibrium will shift to reduce the effect of this pressure change.
If the pressure increases, the equilibrium will shift in the direction with a total of fewer moles
If the pressure decreases, the equilibrium will shift in the direction with a total of more moles.
3. Temperature Changes
Temperature changes associated with heat release or absorption. In the equilibrium reaction, if the reaction to the right absorbs heat (the endotherm reaction), then the reaction to the left will release the heat (exothermic reaction). Vice versa. However, the writing of the termokimianya equation will refer to the reaction to the right.
By Le Chatelier Principles:
When the reaction temperature is raised, the equilibrium will shift toward a heat-absorbing reaction (an edoterm reaction)
When the reaction temperature is lowered, the equilibrium will shift toward a heat-releasing reaction (exothermic reaction)
Please check the following vidio:
https://www.youtube.com/watch?v=V0Ak5e7L90M
Give an example of equilibrium reaction?
BalasHapus2 SO2(g) + O2(g) ←⎯⎯⎯⎯→ 2 SO3(g)
HapusExplain the differences along with exothermic reaction examples and endothermic reactions
BalasHapus1. The endothermic reaction absorbs energy from the surrounding environment, whereas in the exothermic reaction energy is released into the environment.
Hapus2. The enthalpy change for the exothermic reaction is negative, and for the endothermic reaction it is positive.
3. Usually, the direction of the spontaneous exothermic reaction, and the opposite of the same reaction is the endotherm.
4. In the endothermic reaction, the product has a higher energy than the energy of the reaction. Therefore, the less stable product of the reactants. In exothermic reactions, products are more stable than reactants, because their energy is lower than the energy of the reactants.
why If the concentration of reagents is increased, then the equilibrium will shift to the right?
BalasHapusBecause it will cause the value of Qc to be smaller than Kc. To return to a balanced state, the reaction will shift toward the product (to the right).
HapusWhy at the time of equilibrium, reagents still exist in the system?
BalasHapusBecause the product can react again to form the reagent in a state of equilibrium dynamic rate to the product equal to preaksi so that the reagent will not run out
HapusPlease explain about reagent ..
BalasHapusreagent is Substances or chemical compounds added with the aim of bringing about a chemical reaction or added to see if the reaction occurs
HapusHow to connect between kc to kp?
BalasHapusThe relationship between Kc and Kp can be derived as:
HapusKp = Kc (RT) Δn
Where Δn is the difference (number of right gas coefficients) and (number of left gas coefficients).