Equilibrium Flashcards
What is a reversible reaction?
Products can reform initial reactants by re-reactants. Reactions take place in both directions at the same time.
What is dynamic equilibrium.
Forward and backward reactions are happening at the same rate.
What is equilibrium?
Concentration of products and reactants remains the same or constant.
What factors affect the position of equilibrium?
Temperature
Pressure
Concentration
How does concentration affect position of equilibrium ?
If the concentration of a recant is increased, the equilibrium will shift to the side of the reaction with the least moles therefore trying to reduce the concentration of the reaction.
State La Chateliers principle.
If a factor affecting rate of reaction is altered, the position of equilibrium shifts to oppose the change to minimise the affect of the change.
State how pressure affects rate of reaction.
When pressure increases, the reaction shifts to the region with fewer molecules to reduce the pressure.
When pressure decreases the reaction shifts to the side win more molecules.
But if same molecules the change in pressure has no effect.
How does a change in pressure affect a reaction with equal moles on both sides ?
No effect
What happens if you increase the temperature of an exothermic reaction ?
It will shift to favour the endothermic reaction to decrease the temperature of surroundings.
What happens if you decrease the temperature of an exothermic reaction ?
Shifts to the right to favour the exothermic reaction to increase the surrounding temperature.
What is an exothermic reaction and it’s symbol.
Negative triangle
Transfers energy to the surroundings to increase surrounding temperature.
Products lower than reactants
What is the symbol and what is an endothermic reaction.
Positive triangle
Absorbs energy from surroundings to reduce surrounding heat.
Products more energy than reactants.
What is the effect of a catalyst on equilibrium ?
Adding a catalyst does not affect the position of equilibrium. Only increases the rate of reaction so the position of equilibrium is revalued faster. But increases forward and backward reaction at same rate.
How is % yield calculated ??
(Actual yield/ theoretical yield) x100
What type of reaction is the hater process and how do you know this.
An exothermic reaction because an increase in temperature decreases yield of ammonia.
What temperature does the haber process occur at and why ?
450 degrees Celsius because although % yield of ammonia will not be at its maximum, a compromise will be made so the reaction occurs at a reasonable rate with a Hugh enough rate to make the reaction economically viable.
What pressure does the haber process occur at and why ?
200 atmospheres. Avery high pressure isn’t used because costs of minting a high pressure would be too high and would therefore mean the reaction wouldn’t be efficient.
What % yield is created by the haber process.
20%
What catalyst is added to the haber process and how does this work.
Iron
Increases rate of reaction without affecting position of equilibrium.
In industry how is ethanol mainly produced ?
Hydration of ethene
What type of reaction is hydration ethene to produce ethanol ?
Exothermic reaction
How is ethanol production optimised during hydration of ethene.
Low temperature to about backward reaction because it is an exothermic reaction.
How is it ensured that all ethene is used up in ethanol production ?
Increases steam concentration but not too much because it could dilute the phosphoric acid catalyst.
What catalyst is added to ethanol production ?
Phosphoric acid.
