3.4. Equilibrium Flashcards
What is the symbol for a reversible reaction?
What is meant by “dynamic” equlibrium?
Both forward and reverse reactions are still occuring at equal rates.
What is meant by a “closed system”?
A system in from which no reactants or products can escape.
When is dynamic equilibrium reached?
When the rates of the forward and reverse reactions are equal and the concentrations of reactants and products are constant.
What is Le Chateliers’ principle?
If the conditions of a chemical system at equilibrium are changed, the system responds by minimising the effect of the changes.
What conditions can be altered to change the position of equilibrium?
temperature
pressure (if gases involved)
concentration
Why would the rate of the forward reaction be initially high?
Because we start with nothing but reactants, the concentration of these is at their highest
Why would the rate of the forward reaction decrease over time?
The concentration of reactants falls as they are turning into products.
Why would the rate of the reverse reaction be zero at start?
Because we start with nothing but reactants, the concentration of products is zero.
Why would the rate of the reverse reaction increase over time?
The concentration of products increases as reactants are turning into products
At what point is dynamic equilibrium reached?
The point in time when the forward and reverse rates are equal
(you can be required to read this from a graph)
What effect does increasing temperature have on the position of equlibrium?
It moves it in favour of the endothermic reaction.
What effect does decreasing temperature have on the position of equlibrium?
It moves it in favour of the exothermic reaction.
What effect does decreasing pressure have on the position of equilibrium?
It moves it in the direction of the highest volume of gas
( highest number of moles)
What effect does increasing pressure have on the position of equilibrium?
It moves it in the direction of the lowest volume of gas
( lowest number of moles )
