LE CHATLIER'S PRINCIPLE

Question 1

Define le Chatelier’s principle. (1)

Answer 1

Le Chatelier’s Principle states that if a system in equilibrium is subjected to a change in concentration, temperature, volume, or pressure, the equilibrium will shift to counteract the imposed change, thus maintaining equilibrium.

Question 2

why is Le Chatelier’s principle important? (1)

Answer 2

It helps predict how a system at equilibrium will respond to changes in its conditions and allows us to manipulate conditions to favour the desired reaction.

Question 3

what are the key concepts when changing the concentration in an equilibrium mixture? (1)

Answer 3

Changes in concentration: If the concentration of a reactant or product is increased, the equilibrium will shift to consume or produce the added substance.

Question 4

what are the key concepts when changing the pressure in an equilibrium mixture? (1)

Answer 4

Changes in pressure/volume: For gaseous reactions, an increase in pressure (or decrease in volume) will shift the equilibrium towards the side with fewer moles of gas.

Question 5

what are the key concepts when changing the temperature in an equilibrium mixture? (1)

Answer 5

Changes in temperature: The effect of temperature change depends on whether the reaction is exothermic or endothermic.

Question 6

what happens if you increase the concentration of the reactants in an equilibrium mixture? (1)

Answer 6

Increase in reactants: Equilibrium shifts towards products

Question 7

what happens if you decrease the concentration of the reactants in an equilibrium mixture? (1)

Answer 7

Decrease in reactants: Equilibrium shifts towards reactants.

Question 8

what happens if you decrease the concentration of the products in an equilibrium mixture? (1)

Answer 8

Decrease in products: Equilibrium shifts towards products.

Question 9

what happens if you increase the concentration of the products in an equilibrium mixture? (1)

Answer 9

Decrease in reactants: Equilibrium shifts towards reactants.

Question 10

what happens if you increase the pressure (decrease the volume) in an equilibrium mixture? (1)

Answer 10

Increase in pressure (decrease in volume): Equilibrium shifts towards the side with fewer moles of gas.

Question 11

what happens if you decrease the pressure (increase the volume) in an equilibrium mixture? (1)

Answer 11

Decrease in pressure (increase in volume): Equilibrium shifts towards the side with more moles of gas.

Question 12

what happens if you change the temperature of an exothermic reaction in an equilibrium mixture? (1)

Answer 12

Exothermic reaction (heat is released): Increasing temperature shifts equilibrium towards the reactants (left).

Question 13

what happens if you change the temperature of an endothermic reaction in an equilibrium mixture? (1)

Answer 13

Endothermic reaction (heat is absorbed): Increasing temperature shifts equilibrium towards the products (right).

Question 14

what are the characteristics of an exothermic reaction? (1)

Answer 14

exothermic reactions release heat to the surroundings.

Question 15

what are the characteristics of an endothermic reaction? (1)

Answer 15

endothermic reactions absorb heat from the surroundings.

Question 16

what effect does a temperature increase have on a exothermic reaction in an equilibrium mixture? (1)

Answer 16

Increasing temperature shifts equilibrium towards the reactants (left).

Question 17

what effect does a temperature increase have on a endothermic reaction in an equilibrium mixture? (1)

Answer 17

Increasing temperature shifts equilibrium towards the products (right).

Question 18

what effect does a temperature decrease have on a exothermic reaction in an equilibrium mixture? (1)

Answer 18

Decreasing temperature shifts equilibrium towards the products (right).

Question 19

what effect does a temperature decrease have on a endothermic reaction in an equilibrium mixture? (1)

Answer 19

Decreasing temperature shifts equilibrium towards the reactants (left).

Question 20

what effect does increasing the temperature of an exothermic reaction have on the Kc constant? (1)

Answer 20

K decreases with increasing temperature

Question 21

what effect does increasing the temperature of an endothermic reaction have on the Kc constant? (1)

Answer 21

K increases with increasing temperature.

Question 22

define the equilibrium constant. (1)

Answer 22

The equilibrium constant, denoted as K, is a numerical value that expresses the ratio of concentrations of products to reactants at equilibrium for a chemical reaction.