Chapter 2: Chemical Equilibrium Flashcards
Do better than Arman (33 cards)
the term that describes a situation where microscopic changes occur but macroscopic do not, because forward and reverse reaction rates are equal.
Dynamic equilibrium.
What must there be for an equilibrium to exist
a closed system
What are the 7 characteristics of a system in equilibrium?
- The system is closed
- Opposite reactions occur at the same rate.
- Equilibrium was reached.
- The concentration of products/reacts are constant.
- Macroscopic properties remain constant.
- Temperature is constant.
- The reaction started with either reactants or products.
What says that if a closed system at equilibrium is subject to a change, a process will occur to counteract that change.
Le Châtelier’s Principle
What, surprisingly, does not affect the position of an equilibrium?
Catalysts.
If you add heat to a system, how will it shift?
In a way to use up the heat (away from heat)
If you remove heat from a system, how will it shift?
To produce heat (towards heat)
If you increase the concentration of a substance in an equilibrium, how will it shift?
To reduce concentration (shift away from substance).
If you decrease the concentration of a substance in equilibrium, how will it shift?
To increase concentration (towards substance).
If you total pressure is increased, what will happen?
Shift towards side with least moles of gas (as shown by coefficients).
If the total pressure is decreased, what will happen?
Shift towards side with more moles of gas (as shown by coefficients).
If the pressure of a particular substance is increased, what will happen?
Shift away from that substance.
How do you alter the concentration of certain ions in equilibrium?
By adding solutions that contain that ion in it, or solutions that will combine with that ion in a certain ratio.
When an equilibrium shifts, the amount each substance shifts depends on what?
Mole ratios.
An equilibrium graph represents what exactly?
How each substance in an equilibrium shifts to accomodate a change and reach an equilibrium again.
What is done to solve the problem in the Haber Process
Moderate temperature and high pressure.
What is a spontaneous reaction?
A reaction that occurs by itself, without interference.
Most spontaneous reactions are what type of reaction?
Exothermic, because it does not always require activation energy.
Why is it unlikely that a spontaneous reaction would be endothermic?
Because endothermic reactions require significant activation energy to react.
How are endothermic reactions still sometimes able to be spontaneous?
Through randomness.
Which word describes the amount of randomness in a system?
Entropy
What can generally be said about the entropy of a system?
It is favoured over ordered states, shifts towards most random side.
What is the symbol for entropy?
Delta-S
What are the two factors that determine spontaneity?
Enthalpy and Entropy.
