Solutions Flashcards
What is required for a chemical reaction to take place?
Collision energy: activation energy, the minimum value of energy required for the reaction to take place
Collision geometry: modules must collide with the correct orientation
What is a exothermic reaction?
Reaction where heat/energy is released
What is needed for an exothermic reaction to take place?
Need to give it a bit of energy
How much energy will the product of an exothermic reaction have?
Less than what it started out with
How much energy will the product of an endothermic reaction have?
More energy than the reactants
Which have higher activation energy, exothermic or endothermic reactions?
Endothermic reactions
What factors affect rate of reaction?
Temperature: increase increases rate of reaction as particle kinetic energy is increased
Concentration: increase increases rate of reaction due to increase in correctly oriented collisions
Particle size: decrease in size increases rate of rector due to increase in surface area
Pressure ( only gasses) & volume: increase pressure or decrease volume increases rate of reaction
Catalyst: reduces activation energy
Definition of equilibrium
At equilibrium the rate of the forward reaction = the rate of the reverse reaction
What are the conditions for equilibrium reactions?
They are dynamic
Must occur in a closed system
Concentrations must be constant
No macroscopic changes take place
What is the equilibrium constant?
Constant value for a certain reaction at a certain temperature
Formula for equlibrium constant
Google the answer
What is importat to remember when calculating equilibrium constant?
Units
How do you figure out what direction a reaction will favor?
Calculating the possible equilibrium constant. If it is lower the one given the forward reaction wil be favored, if it is high the backwards will se favored
What are the 3 possibilities for the solution of Q in comparison to k?
Q = k, equilibrium
Q > k, reaction go left, reverse reaction is favored
Q < k, reaction go right, forward reaction is favored
What does Le Chatelier’s principle state?
If we change something in a reaction it will adjust so equilibrium is reached again
How does added reactants change the equilibrium?
Reaction goes right, forward reaction is favoured
How does added products change the equilibrium?
Equilibrium goes left, reverse reaction is favoured
How does increase in pressure (decrease in volume) change the equilibrium? (Gasses only )
Side with less molecules is favoured
How does decrease in pressure (increase in volume) change the equilibrium? (Gasses only)
Side with more molecules is favoured
How does increase in temperature of an endothermic change the equilibrium?
Increase in product, reverse reaction is favoured
How does increase in temperature of an exothermic change the equilibrium?
Decreases product & forward reaction is favoured
What happens to the equilibrium constant k when temperature is changed?
It changes as well