10C- calculating pH-Table 1 Flashcards
Define
acidic solution
Solution containing a greater concentration of hydronium ions than hydroxide ions
Define
basic solution
Solution containing a greater concentration of hydroxide ions than hydronium ions
Define
neutral solution
Solution containing an equal concentration of hydronium and hydroxide ions
Define
autoionization
Process by which an atom or molecule spontaneously forms ions
Define
ionic product of water (Kw)
Expression of the concentration of ions present in water at 25 °C
Define
pH
Measure of the concentration of hydronium ions in a solution
Define
pH scale
pH values arranged on a logarithmic scale
Ionic(n.) product
definition
-Ionic product(n.)=The product of
concentrations of ionic species
Ionisation(v.)
definition
-Ionisation(v.)=Conversion of substance into
ions.
Acidity definition
-Acidity(adj.)=level of acid in a substance
what happens when water is ionised
H2O(l) + H2O(l) H3O+(aq) + OH−(aq)
water acts as a weak acid and weak base
list some monoprotic acids
hydrochloric acid (HCl), ammonium (NH4), nitric acid (HNO3), ethanoic acid (CH3COOH)
HANE (hydrochloric acid, ammonium, nitric acid, ethanoic acid)
define monoprotic
species that can only donate one proton, H+, during ionisation
list some diprotic acids
sulfuric acid (H2SO4), carbonic acid (H2CO3), hydrogen sulfide (H2S), selenous acid (H2SeO3)
SCHS ( sulfuric acid, carbonic acid, hydrogen sulfide, selenous acid)
define diprotic
species that can donate up to two protons, H+, during ionisation
list some triprotic acids
phosphoric acid (H3PO4), citric acid (C6H8O7), arsenic acid (H3AsO4), boric acid (H3BO3)
PCAB
define triprotic
species that can donate up to three protons, H+, during ionisation
list some amphiprotic acids
water (H2O), hydrogen sulfate ( HSO4(-)),hydrogen carbonate (HCO3(-)), di hydrogen phosphate (H2PO4(-)), hydrogen phosphate ( HPO4(2-))
define amphiprotic
species that can either donate or accept a proton, H+
define pH
measure of the concentration of hydronium ions in a solution
kW formula (aka ionic product formula)
Kw = [H3O+] × [OH−]
Kw = (1.00 × 10−7 M) × (1.00 × 10−7 M)
Kw = 1.00 × 10^−14 M2
pH formula
pH = −log10[H3O+]
what is kW
the ionic product of water: expression of the concentration of ions present in water at 25°C
Kw is always equal to 1.00 ⨉ 10-14 M^2 at 25°C
This formula only valid at 25 degrees Celsius
If neutral pH is still defined as when [H3O+] = [OH–], what would be considered neutral pH at 100°C, assumingKwis equal to 51.3 × 10–14M2?
H3O x OH = 51.3 x 10^-14
H3O=OH
H3O x H3O = 51.3 x 10^-14
H3O= √51.3 x 10^-14
H3O= 7.162 x 10^-7
pH= -log 10 (7.16 x 10^-7)
pH=6.14
Acid solutions ratio of H3O+ and OH- concentration
pH 7 < [H3O+] >1.0 × 10−7 M and [OH−] < 1.0 × 10−7M
Neutral solutions ratio of H3O+ and OH- concentration
pH = 7, [H3O+] = [OH−] = 1.0 × 10−7 M
basic solutions ratio of H3O+ and OH- concentration
pH 7 >[H3O+] <1.0 × 10−7 M and [OH−] >1.0 × 10−7M
how to calculate pH
pH = −log10[H3O+]
how to calculate H3O concentration
[H3O+] = 10^−pH
what factor is pH change
every increase or decrease in pH by 1 means that there was a change in the concentration of H3O by a factor of 10
Calculate the pH of a 0.30 M solution of hydrochloric acid at 25 .
[HCl] = [H3O+] = 0.30 M
pH = −log10[H3O+]
pH = −log10 (0.30 M)
pH = 0.52
Explain the
autoionisation of water.
-Pure water
undergoes a tiny degree of ionisation with itself
-This is possible
due to water’s amphiprotic nature
H2O(l){acid}
+ H2O(l){Base}⇌ H3O^(+)(aq) + OH^(-)
-There will be
very low concentrations of product as only a small amount of this reaction
will occur due to the strenght of the acid and base being low.
What does pH stand
for(not necessary but fun)
What
does pH stand for?=Potenz of hydrogen=power of hydrogen=
-p=power=originates
from the german word potenz
-H=hydrogen
What is the pH
scales and what does it do
-measurement of
acidity= simplified further using measurement of pH
-pH scale=
measurement of acidity of a solution on a scale of 0-14(this only valid at 25 degrees Celsius )
