unit 3 KA4 - equilibria

Question 1

what occurs in a closed system

Answer 1

reversible reactions attain a state of dynamic equilibrium when the rates of forward and reverse reaction are equal

Question 2

what conditions are required for the reversible reactions to attain a state of dynamic equilibrium

Answer 2

• closed system

- rates of forward and reverse reactions are equal

Question 3

when do the concentrations of reactants and products remain constant

Answer 3

at equilibrium

Question 4

is it true that the concentrations of reactants and products remain constant but are rarely equal

Answer 4

yes

Question 5

how to chemists maximize profits

Answer 5

they employ strategies to move the position of equilibrium in favor of the products

Question 6

what can be predicted in a given reversible reaction

Answer 6

the effect of altering temperature or pressure or of adding/removing certain reactants/products

Question 7

what does the addition of a catalyst do

Answer 7

it increases the rates of the forward and reverse reactions equally

Question 8

what is the relationship between catalysts and equilibrium

Answer 8

catalysts increase the rate at which equilibrium is achieved but do not affect the position of the equilibrium

Question 9

what effect does increasing temperature in an exothermic reaction have on the position of the equilibrium

Answer 9

it shifts the position to the left because an increase in temperature will lead to the endothermic reaction being favoured

Question 10

what effect does decreasing the temperature on an exothermic reaction have on the position of the equilibrium

Answer 10

it shifts the positiion to the right because the decreased temperature leads to the exothermic reaction being favoured

Question 11

what effect does increasing the temperature on an endothermic reaction have on the position of the equilibrium

Answer 11

it shifts the position to the right because the endothermic reaction is favoured

Question 12

what effect does decreasing the temperature of an endothermic reaction have on the position of the equilibrium

Answer 12

it shifts it to the left because the exothermic reaction is favoured

Question 13

what effect does increasing the pressure have on a reaction where there are more moles of gas on the right than the left have on the position of the equilibrium

Answer 13

it moves to the left because it favours the side with the less pressure

Question 14

what effect does decreasing the pressure of a reaction where the products have higher moles of gas than the reactants have on the position of the equilibrium

Answer 14

it shifts to the right because the side with the highest pressure ie the highest moles of gas is favoured

Question 15

what effect does a catalyst have on the position of the equilibrium

Answer 15

none

Question 16

what effect does changing concentration of reactants have on the position of the equilibrium

Answer 16

shifts to the right because there are more reactants to turn into products

Question 17

what effect does changing to concentration of products have on the position of the equilibrium

Answer 17

it shifts it to the left because there are more products that they want to turn back into reactants