Chemistry Test #2 Flashcards
Buffered solution
- Resists change in pH
- Weak acids or bases with a common ion
What is the domain of Kinetics?
The reaction pathway, getting over the hill. Rate of reaction depends on the pathway from reactants to products. How fast the reaction is.
What does thermodynamics tell us?
Whether a reaction is spontaneous based only on the properties of reactants and products. How stable a reaction is.
What do thermodynamics allow us to predict?
The direction which a process will occur.
What is the common ion effect?
Same ions - eq shift bc of addition of ions already present in solution
What is the common ion effect an application of?
Le Chatelier’s Principle
What kind of solution makes up a buffer solution?
Weak acids + strong base
Strong acid + weak base
What are you adding when you add base
OH-
What are you adding when you add acid
H+
When does [HA] = [A-]
Half equivalence point
pH=pKa
What is the equivalence point for a strong acid and strong base?
pH = 7
What is q
Heat: transfer of energy between two objects due to a temperature difference.
What is w
Work: defined as a force acting over a distance.
Why can you only add small quantities to a buffered solution?
Large qualities overload one side and there is no longer equilibrium.
What happens when you add OH-
absorbs H+, less reactant causes a shift of equilibrium.
What does a lower pKa mean?
Lower pH, more acidic, stronger acid, higher H+
What happens if you increase the concentration of a aqueous solution that has a common ion with the reactant?
Solubility decreases.
What is the equation for Gibbs free energy?
∆G = ∆H - T∆S
∆H = Change in enthalpy
T = Temperature
∆S = Change in entropy (Disorder)
∆G = Gibbs Free energy
What is the equation for internal energy?
∆E = q + w
What does is mean if q is negative?
Exothermic