Acids and Bases Flashcards
Solutions that are acidic tend to have pHs ____ than 7.
Less
Solutions that are basic tend to have pHs ______ than 7.
Greater
At 25°C only, the pH of pure water is
7.
What do acids do in acid/base reactions?
Donate H+
What do bases do in acid/base reactions?
Accept H+
In math equations, H+ can be replaced with
H3O +.
What are the strong acids?
HCl
HBr
HI
HNO3
H2SO4
HClO4
What are the strong bases?
Group 1A and 2A metals bonded to OH-
For solutions containing weak acids only, a useful formula is
[H+] = sqrt([weak acid]•Ka)
For solutions containing weak bases acids only, a useful formula is
[OH-] = sqrt([weak base]•Kb)
Percent ionization/dissociation for weak acid formula
% Diss = [H+]/[weak acid]o • 100%
As you dilute a weak acid or weak base, the percent ionization of the weak acid or weak base
Increases.
If a salt contains a weak acid, it will make a(n) _______ solution when dissolved into.
Acidic
If a salt contains a weak base, it will make a(n) _______ solution when dissolved in water.
Basic
Electronegative atoms make weak acids _________
Stronger.
CxHy groups make weak acids
Weaker.
Electronegative atoms make weak bases
Weaker.
CxHy groups make weak bases
Stronger.
Resonance makes a conjugate base ________ stable.
More
Buffer solutions must contain a ___________________.
Weak conjugate acid/base pair
Ex. HCOOH and HCOO-
pH at equivalence point in a strong acid/weak base titration
pH < 7 (due to CA of weak base)
pH at equivalence point in a weak acid/strong base titration
pH > 7 (due to CB of weak acid)
pH at equivalence point in a strong acid/strong base titration
pH = 7
pH at equivalence point in a weak acid/weak bad titration
pH could be greater than, less than, or equal to 7. Determined by whichever conjugate is stronger.
pH = pKa when
[HA] = [A-] (half-equivalence point)
Greater buffer capacity is related to having
more moles of weak acid or weak base in buffer solution.
An indicator should be selected for titration that has a pKa close to the pH at
the equivalence point.
