Acids and Bases Flashcards
strong acid - [H+] =
10^-pH
strong acid - -log(pH) =
[H+]
define Bronsted-Lowry acid
proton donor
define Bronsted-Lowry base
proton acceptor
number of protons in a molecule of monoprotic acid
1
number of protons in a molecule of diprotic acid
2
equation of Kw in the ionic production of water
Kw = [H+][OH-] = Kc[H2O]
Equation of Kc in the ionic production of water
Kc = [H+][OH-]/[H2O]
the effect of temperature on the pH of water and why
as temperature increases, pH decreases (as more [H+])
the effect of temperature on the ionic equilibrium of water
equilibrium moves to the right to oppose change
equation for ionic production of water
H2O -> H+ + OH-
is enthalpy change of the ionic product of water endo or exothermic
endothermic
how can water have a lower pH but still be neutral?
because H+ increases but it still = OH-
in pure water what does [OH-] =
[H+]
in pure water, what does Kw =
[H+]^2
in a strong base what does [H+] =
Kw/[OH-] or 10^-14/[OH-]
steps in calculating pH of mixtures of strong acids and strong bases
calculate mols of H+ and OH-
calculate XS mols H+ or OH-
calculate conc. of XS H+ or OH-
calculate pH
equation for a strong acid
HX -> H+ + X-
equation for a weak acid
HX H+ + X-
is HCl strong or weak
strong
are carboxylic acids strong or weak
weak
is sulphuric acid strong or weak
strong
is nitric acid strong or weak
strong
name a diprotic acid
sulphuric acid
is barium hydroxide strong or weak
strong
is potassium hydroxide strong or weak
strong
is ammonia strong or weak
weak
is sodium hydroxide strong or weak
strong
name a dibasic base
barium hydroxide
for a weak acid Ka =
[H+][A-]/[HA]
for a weak acid pKa =
-log Ka
units for Ka
moldm^-3
relationship between Ka and strength of acid
the bigger the value the stronger the acid
relationship between pKa and strength of acid
the smaller the value the stronger the acid
in a solution of a weak acid in water with nothing else added [H+] =
[A-]
in a solution of a weak acid in water with nothing else added [HA] initial =`
[HA]
in a solution of a weak acid in water with nothing else added Ka =`
[H+]^2/[HA]
equation for reaction of a weak acid and a strong base
HA + OH- -> A- + H2O
steps to finding the pH in reactions between weak acids and strong bases for XS HA
calculate mols HA calculate mols OH- calculate mols XS calculate mols HA left and A- formed use Ka to find [H+] find pH
steps to finding the pH in reactions between weak acids and strong bases for XS OH-
calculate mols HA calculate mols OH- calculate mols XS calculate conc. OH- use Kw to find H+ find pH
steps to finding the pH in reactions between weak acids and strong bases for when HA = OH-
calculate mols HA
calculate mols OH-
calculate mols XS
pH = pKa of weak acid
2H+ +CO3 2- ->
H2O + CO2
H+ + HCO3- ->
H2O + CO2
H+ + NH3 ->
NH4+
define equivalence point
mols of alkali equals mols of acid present
define buffer solutions
solution resists changes in pH when small amounts of acid or alkali are added
what sort of buffer solutions have pH > 7
basic buffer solutions
what sort of buffer solutions have pH < 7
acidic buffer solutions
component in acidic buffer solution
weak acid + one of its salts
component of basic buffer solution
weak base and one of its salts
which equation can you use to find pH of acidic buffer solutions
Ka = [HA]/[A-]
