Chapter 16: Acid and Base Equalibria Flashcards
What is acid dissociation?
The production of a hydronium ion and a conjugate base in solution.
How do you find the degree of ionization?
Take the change in concentrations (x) and divide by the known concentration of the original acid ( ___ M).
What is Ka what is it used for?
It is the ionization constant for acids; It tells us whether the solution is basic, neutral, or acidic.
What is the relationship between Ka and acid strength?
The stronger the acid, the larger the ionization constant Ka will be.
What is the rule of 100 and what does it help you do?
If the concentration of an acid is with 100 times the Ka value, then you can assume that the concentration does not change significantly between each species. This means that in a ionization constant problem, anything with ___ - X can just become ____, because the change is so small, it is insignificant.
What is a polyprotic acid and what does this do to acid ionization problems?
It is where an acid has multiple hydrogen ions that can stripped from each molecule. It makes it so that you have to do two calculations of a change factor (x) and the second problem uses the data from the 1st part of the problem to do so [x from Ka1].
What is the difference between Ka and Kb?
A stands for acid ionization, B stands for base ionization.
What is hydrolysis?
When an ion reacts with H2O from the production of hydroxide/hydronium and conj. acid/base from a base/acid rxn respectively.
How do different strong/weak acid and base combinations affect hydrolysis with a salt solution?
Strong Acid + Strong Base —> The salt has no reaction, solution is neutral.
Strong Acid + Weak Base —> Produces a hydronium ion, solution is acidic.
Weak Acid + Strong Base —> Produces a hydroxide ion, solution is basic.
Weak Acid + Weak Base —> Both ions hydrolyze. To determine pH depends on strength of each species. If:
Ka > Kb —> Acidic Solution
Ka = Kb —> Neutral Solution
Ka Basic Solution
How do you obtain Ka or Kb from knowing one?
Kw = Ka * Kb
Where Kw is the ion-product constant for H2O.
Kw = 1e^-14
What is the common ion effect?
A shift in ionic equilibrium by adding some ion that is part of the equilibrium of the solution.
Example: Adding HCl to a weak acid and water solution yields the increase in hydronium ions, which shifts the equilibrium to the right.
What is a buffer?
A solution that can resist change in pH when limiting the amount of acid or base added.
What are the steps to solving a buffer problem?
- Convert all givens to useable measurements.
- Make an ICE Table.
- Solve for remaining components of x.
- Answer the question(s).
How do you compare two solutions?; One is a buffer and the other is a normal solution.
Find pH numbers and subtract one calculated number from the other to find the differences between them.
What is Henderson-Hasselbalch Equilibrium?
It is an equation to determine the pH when combining acids and bases in solution. Equation:
pH = pKa (pH of acid) + log ( base conc. / acid conc.)
