acids and bases intro. acid/base definitions arrhenius model acids produce hydrogen ions in...
TRANSCRIPT
![Page 1: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/1.jpg)
Acids and Acids and Bases introBases intro
![Page 2: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/2.jpg)
Acid/Base Definitions Arrhenius Model
Acids produce hydrogen ions in aqueous solutions
Bases produce hydroxide ions in aqueous solutions
Bronsted-Lowry Model Acids are proton donors Bases are proton acceptors
![Page 3: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/3.jpg)
Acid DissociationAcid Dissociation
HA H+ + A-
Acid Proton Conjugate
base
][
]][[
HA
AHKa
Alternately, H+ may be written in its hydrated form, H3O+ (hydronium ion)
![Page 4: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/4.jpg)
for example…for example…
HCl H+ + Cl-
Acid Proton Conjugate
base
][
]][[
HCl
ClHKa
![Page 5: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/5.jpg)
Dissociation of Strong AcidsDissociation of Strong AcidsStrong acids are assumed to dissociate completely in solution.
Large Ka or small Ka?Reactant favored or product favored?
![Page 6: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/6.jpg)
Dissociation Constants: Strong Dissociation Constants: Strong AcidsAcids
AcidFormul
aConjugate
BaseKa
Perchloric HClO4 ClO4- Very large
Hydriodic HI I- Very large
Hydrobromic HBr Br- Very large
Hydrochloric HCl Cl- Very large
Nitric HNO3 NO3- Very large
Sulfuric H2SO4 HSO4- Very large
Hydronium ion H3O+ H2O 1.0
![Page 7: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/7.jpg)
Dissociation of Weak AcidsDissociation of Weak AcidsWeak acids are assumed to dissociate only slightly (less than 5%) in solution.
Large Ka or small Ka?Reactant favored or product favored?
![Page 8: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/8.jpg)
Dissociation Constants: Weak Dissociation Constants: Weak AcidsAcids
Acid FormulaConjugate Base
Ka
Iodic HIO3 IO3- 1.7 x 10-1
Oxalic H2C2O4 HC2O4- 5.9 x 10-2
Sulfurous H2SO3 HSO3- 1.5 x 10-2
Phosphoric H3PO4 H2PO4- 7.5 x 10-3
Citric H3C6H5O7 H2C6H5O7- 7.1 x 10-4
Nitrous HNO2 NO2- 4.6 x 10-4
Hydrofluoric HF F- 3.5 x 10-4
Formic HCOOH HCOO- 1.8 x 10-4
Benzoic C6H5COOH C6H5COO- 6.5 x 10-5
Acetic CH3COOH CH3COO- 1.8 x 10-5
Carbonic H2CO3 HCO3- 4.3 x 10-7
Hypochlorous HClO ClO- 3.0 x 10-8
Hydrocyanic HCN CN- 4.9 x 10-10
![Page 9: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/9.jpg)
Self-Ionization of WaterSelf-Ionization of Water
H2O + H2O H3O+ + OH-
At 25, [H3O+] = [OH-] = 1 x 10-7
Kw is a constant at 25 C:
Kw = [H3O+][OH-]
Kw = (1 x 10-7)(1 x 10-7) = 1 x 10-14
![Page 10: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/10.jpg)
Calculating pH, Calculating pH, pOHpOHpH = -log10(H3O+)
pOH = -log10(OH-)
Relationship between pH and Relationship between pH and pOHpOH pH + pOH = 14
Finding [HFinding [H33OO++], [OH], [OH--] from pH, pOH] from pH, pOH
[H3O+] = 10-pH
[OH-] = 10-pOH
![Page 11: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/11.jpg)
pH and pOH Calculations
H + O H -
pH pO H
[O H -] = 1 x 10 - 1 4
[H + ]
[H + ] = 1 x 10 - 1 4
[O H -]
p O H = 14 - p H
p H = 14 - p O H
pOH
= -l
og[O
H- ]
pH =
-log
[H+
]
[OH
- ] = 1
0-pO
H
[H+
] = 1
0-pH
![Page 12: Acids and Bases intro. Acid/Base Definitions Arrhenius Model Acids produce hydrogen ions in aqueous solutions Bases produce hydroxide ions in aqueous](https://reader036.vdocuments.net/reader036/viewer/2022062304/56649e625503460f94b5e052/html5/thumbnails/12.jpg)
pH pH ScalScal
ee