dynamic equilibrium 2.2

what does it mean when a chemical reaction is at equilibrium

the forward and reverse reactions are occurring at the same rate

what are some things to remember when a reaction is at equilibrium?

macroscopic properties (colour, concentrations, pressure and temperature) are constant

reaction is incomplete and both reactants and products are present

reactants are forming products at the same rate that products are forming reactants and the other way around

what does equilibrium position means + describe ‘to the left’ and ‘to the right’

equilibrium position means which direction of the reaction is favoured, what position does the reaction favours more.

when the equilibrium is ‘to the left’: the reaction favours the reverse reaction because there are more reactants present

when the position is ‘to the right’; the forward reaction is favoured because there are more products present

give a brief summary of what occurs to the rate of reactions (forward and reverse) of a reversible reaction

initially, the forward reaction is increased consuming the high concentration of reactants, and forming products. Because the concentration of reactants decrease, the reaction then begins to increase the rate of reverse reaction to then produce more reactants, slowing down the forward reaction. this occurs until both directions are equal and are occurring at the same rate.

what is an equilibrium constant

numerical value that relates the concentrations of reactants and products in a system at equilibrium

what can change the equilibrium constant

only temperature can affect the equilibrium (K) constant

differentiate between a small K and large K

small K= reaction favours the reactants (reverse reaction Is favoured, producing more reactants)

large K= reaction favours the products (forward reaction is favoured, producing more products)

define equilibrium yield

number of products present at equilibrium

define le chateliers principle and what does it state

based on the effect of changed conditions in a reaction at equilibrium. it states that when a reaction at equilibrium experiences a change, the reaction will adjust to oppose the change

what would happen if you add higher concentration of reactants?

eq. position would move to the right, favouring the forward reaction because the reactants must be consumed to produce products, re-establishing equilibrium

what would happen if you add higher concentration of products?

eq. position would move to the left, favouring the reverse reaction because the products must be consumed to produce reactants, re-establishing equilibrium

what would happen if you increase the temperature of a exothermic reaction

eq. position is to the left, favouring the reverse reaction. heat was released from the reaction, therefore the reverse reaction must occur to use heat, establishing equilibrium.

what would happen if you increase the temperature of an endothermic reaction

eq. position moves to the right, favouring the forward reaction because the heat must be used up. (heat is used up in the forward rxn)

what happens if you increase the conc of a substance?

favours the direction that uses up the substance. the side that has less particles

what happens if you increase the pressure?

favours the direction that decreases the pressure

what happens if you increase the temperature?

favours the direction that decreases the temperature

what happens if you add water to a reaction?

dilutes the substances, decreasing the concentration of all aqueous substances.

according to le chateliers principle; the reaction will favour the direction that produces more moles of aqueous substances because It will therefore increase the overall concentration of ions, re-establishing equilibrium.