Chemical Equilibrium Systems Including Acids and Bases Flashcards
Static Equilibrium:
Equal and opposite forces are applied. Like a stand-still game of tug-of-war.
Dynamic Equilibrium:
The rate of both processeses are occurring equally.
Gas equilibrium must be contained in a…
sealed container/closed system.
Aqueous equilibrium (for Chem 30) can occur in an open beaker because…
the rate of evaporation is insignificant.
How do you recognize the products in an equilibrium graph?
They start at 0 mol/L.
How do you recognize the reactants in an equilibrium graph?
They start at a given concentration. (not 0 mol/L)
How do you infer the coefficients in equilibrium equations from a graph?
The rate of change = slope, and the slope relates to the coefficient. The larger the coefficient, the steeper the slope.
When can you tell equilibrium is reached on a graph?
When the concentrations stop changing.
What two things is the rate of reaction affected by?
Concentration of reactants, pressure in the equation (changes coefficients).
If Kc>1:
Products are favoured, reaction proceeds > 50%
If Kc<1:
Reactants are favoured, reaction proceeds < 50%
What is not included in a Kc expression?
Pure solids, water (in aqueous equilibrium), and pure liquids (in gaseous equilibrium).
How do you complete an ICE chart step-by-step?
- Label.
I = [initial] mol/L
C = [change] mol/L
E = [equilibrium] mol/L - Place in given values, if the initial [ ] of a substance is not given, assume it is 0.
- Find the change value and use it to find the change value of everything else, multiplying by coefficients if necessary.
- Find final equilibrium values and use them in sub and solve equations.
Le Chatelier’s Principle:
If stress is applied to a system at equilibrium, the system responds to minimize that stress. Any stress that causes a response will change concentration.
What effect do catalysts have on equilibrium?
They do not effect the position of equilibrium, they only cause the system to reach equilibrium more rapidly. (Kc is unaffected)
What type of equilibrium system(s) does pressure affect?
Gaseous equilibrium.
What will adding or removing a reactant or product do to equilibrium?
It will shift equilibrium away from what is added or towards what is removed.
How will increasing/decreasing pressure affect equilibrium?
An increase in pressure will shift the equilibrium towards the side that has fewer gaseous mols. A decrease in pressure will shift the equilibrium towards the side the has more gaseous moles. If the gaseous mols are equal, there will be no effect.
How does temperature affect equilibrium?
Follows the add-away rule. With an increase in temperature (exothermic), the rate of reverse reaction increases and equilibrium shifts left. Kc will get smaller. With a decrease in temperature (exothermic), the rate of reverse reaction decreases and the equilibrium shifts right. Kc will get larger.
Acid:
A substance that donates protons (H+(aq)).
Strong Acid:
Ionizes 100%.
Weak Acid:
Ionizes partially at most concentrations
Base:
Dissolves in water, bitter, slippery, litmus turns blue, conductive, and neutralizes acids. Accepts protons (H+(aq)) and dissociates 100% at all concentrations.
When strong acids are put at equilibrium, which side is favoured?
Products.
What makes an acid organic?
It has carbon and oxygen