Reversible reactions and dynamic equilibrium

Question 1

What is a reversible reacton?

Answer 1

-products of chemical reaction can react to produce original reactants :)

Question 2

finish off the sentence:

• if a reversible reaction is exothermic in one direction it is…
• energy transferred in each case is

Answer 2

• endothermic in the opposite direction

- the same amount/equal

Question 3

what is the definition of equilibrium?

Answer 3

-when the reverse and forward reaction occur at the exact same rate- rates are equal

Question 4

How is equilbrium reached?

Answer 4

• When a reversible reaction occurs in apparatus which prevents the escape of reactants and products (closed system basically)
• equilibrium is reached when the forward and reverse reactions occur at the same rate

Question 5

What happens if a system is at equilibrium and a change is made to any condition?

Answer 5

-the system responds to counteract the change

Question 6

What is the effect of changing concentration?

Answer 6

-If the concentration of one of the reactants or products is changed, the system is no longer at equilibrium and the concentrations of all the substances will change until equilibrium is reached again.

Question 7

What will happen if the concentration of reactants is increased?

Answer 7

• if the concentration of a reactant is increased, system will try to decrease it by forming more products until equilibrium is reached again

Question 8

what will happen if the concentration of product is decreased?

Answer 8

• If the concentration of a product is decreased, system tries to increase it by reacting more reactants until equilibrium is reached again.

Question 9

What will happen if the temperature of a system at equilibrium is increased?

Answer 9

-equilibrium will shift and favour the endothermic reaction to try and decrease temperature

-the relative amount of products increases for an endothermic reaction
• the relative amount of products decreases for an exothermic reaction.

Question 10

what will happen if the temperature of a system at equilibrium is decreased?

Answer 10

• equilibrium will shift and favour the exothermic reaction to increase the temperature and produce more heat

-more products formed for exothermic reaction
less reactants for endothermic reaction

Question 11

What will happen if the pressure is increased in a gaseous reaction?

Answer 11

• equilibrium will shift toward the side with smaller number of molecules to try and decrease pressure
• look at symbol equation and count the big numbers for each side!

Question 12

what will happen if pressure is decreased in gaseous rewaction?

Answer 12

• equilibrium will shift toward side with larger number of molecules to try and increase pressure
• to work out: count big numbers in equation on both sides!

Question 13

what would happen if the pressure was equal on both sides?

Answer 13

-same number of molecules on both side-no effect