Equilibria

Question 1

how can equilibrium be reached?

Answer 1

in a closed system
- reacted and products can’t escape

Question 2

How do you know when equilibrium has been reached?

Answer 2

when the properties of the system (e.g. colour density) don’t change with time

Question 3

What are the features of dynamic equilibrium?

Answer 3

Forward rate = backward rate

Concentration remains constant

Question 4

What is Le Chatelier’s principle?

Answer 4

Equilibrium will shift to oppose the change

Question 5

What three factors affect a position of equilibrium?

Answer 5

concentration
Pressure
Temperature

Question 6

How does concentration affect the position of equilibrium?

Answer 6

add a chemical (inc concentration) equilibrium moves to get rid of it

remove a chemical (decrease concentration) equilibrium move to make more of it

Question 7

How does pressure affect the position of equilibrium?

Answer 7

only affects chemical equilibrium that involves gases

raise pressure - equilibrium moves lower it
Lower pressure - equilibrium moves to raise it

Question 8

How is the temperature affect the position of equilibrium?

Answer 8

Increase temp - equilibrium moves to cool it

decreased temp - equilibrium moves to heat it

Question 9

what is an exothermic reaction?

Answer 9

Gives out heat to the surroundings

Question 10

What is an endothermic reaction?

Answer 10

Takes and heat from surroundings

Question 11

What happens to equilibrium if temperature is increased?

Answer 11

shifts to oppose this equilibrium

shifts to endothermic direction to try reduce temperature by absorbing added heat

Question 12

what happens to equilibrium if temperature is decreased.

Answer 12

equilibrium shifts in exothermic Direction to try increase the temperature by giving out the added heat

Question 13

what effect does a catalyst have on the yield and position of equilibrium?

Answer 13

none

Question 14

what effect does equilibrium have on yeild?

Answer 14

equilibrium shift to right = yield increases
Shifts two left = yield decreases

Question 15

What is the haber process formula?

Answer 15

N2 + 3H2 ⇌ 2NH3

Question 16

what is the Haber process?

Answer 16

The synthesis of ammonia from nitrogen and hydrogen

Question 17

what is the optimum temperature in the Haber process?

Answer 17

The Haber processes exothermic

the best equilibrium yield of ammonia is obtained at low temperatures

so equilibrium moved to the right

rate of reaction is slow

Question 18

what is the optimum pressure in the Haber process?

Answer 18

the Haber process is favoured at high-pressure

increasing the pressure moves equilibrium to the side with fewer moles of gas

Higher pressure produces greater equilibrium of ammonia

Question 19

What is a compromised condition?

Answer 19

Give a balance between yield rate and cost

Question 20

what is homogeneous equilibrium?

Answer 20

A system where reactant and products are in the same phase

Question 21

What is the equation for Kc

Answer 21

Kc = [C] [D] (products)
————
[A] [B] (reactants)

Question 22

Where is equilibrium if Kc value is less than 1

Answer 22

equilibrium lies towards the reactants

Question 23

Where is equilibrium if Kc value is greater than 1

Answer 23

towards the products