Equilibria Flashcards
What is equilibrium mixture?
This is when products are formed when they react together an dthe reactants formed again, so that instead of reactants or products you get a mixture of both.
Eventually you get a mixture in which rhe proportions of all three components remain constant
What is Le Chatelier’s principle?
If a system at equilibrium is disturbed, the equilibrium moves
in the direction that tends to reduce the disturbance.
What happens if you increase reactant at equilibrium?
If the proportion of reactants in the equilibrium mixture is increased, the equilibrium is moved to the left, or in the backward direction.
What happens if you increase reactant at equilibrium?
If the proportion of reactants in the equilibrium mixture is increased, the equilibrium is moved to the left, or in the backward direction.
What happens to equilibrium when you add a catalyst?
Catalysts have no effect on the position of equilibrium so they do not alter composition of the equilibrium mixture
do allow equilibrium co be reached
more quickly
What factors affect the position of the equilibrium?
Temperature
The concentration or species involved
The pressure
In terms of Le Chatelier principle - what happens when you increase concentration at equilibrium?
Le Chatelier’s principle says that the equilibrium will shift in the direction that tends to reduce the concentration of this reactant.
Explain how increasing concentration of reactants (in Le Chatelier principle) affect the reaction?
A(aq) + B(aq) <==> C(aq) + D(aq)
Adding some extra A - this would increase the concentration of A. The only way that this system can reduce the concentration of A, is by some of A reacting with B (so forming more C and D). So, adding more A uses up more B, produces more C and D, and moves the equilibrium to the right.
What conditions need to be meet for the reaction to reach equilibrium?
Equilibrium can only be reached in a closed system (one where the reactant and products can’t escape).
Equilibrium can be approached from either direction (in from liquid or from vapor) and the final equilibrium position will be the same (as long as conditions, such as temperature and pressure, stay the same).
Equilibrium is a dynamic process. It is reached when the rates of two opposing processes, which are going on all the time
When equilibrium is reached macroscopic properties in the system do not change over time: density, concentration, colour, and pressure
How does a chemical reaction go to equilibrium?
A + B <==> C + D
At the start of the reaction the forward rate is fast, because A and B are plentiful. There is no reverse reaction because there is no C and D.
Then as the concentrations of C and D build up, the reverse reaction speeds up. At the same time the concentrations of A and B decrease so the forward reaction slows down.
A point is reached where exactly the same number of particles are changing from A + B to C + D as are changing from C + D to A+ B. Equilibrium has been reached.
{The equilibrium mixture can have any proportions of reactants and products - the proportion depends on the conditions: temperature, pressure and concentration}
What happens if you increase temperature at equilibrium according to Le Chatelier’s principle?
Le Chatelier’s principle tells us that if you increase the temperature, the equilibrium moves in the direction that cools the system down. To do this it will move in the direction which absorbs heat (is endothermic)
What experiment can be done to support Le Chatellers principle?
1) You contain the gas mixture is in a syringe.
2) You then put the syringe immersed in warm water along with another syringe containing the same volume of air for comparison.
3) The plunger of the syringe containing air will rise as the air expands. The plunger of the syringe containing (reactant gas) will also rise but by a greater amount. This indicates that more molecules of gas have been formed in this syringe. (this is because the equilibrium moved position)
Why is le chataliers principle important to understand?
help find the best conditions for increasing the yield of a chemical reaction
What can ammonia be used for?
It can be used to make fertilizers
It can be used to make synthetic fibres
What factors effect Kc
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