definitions. arrhenius acids and bases acids release hydrogen ions in water. bases release hydroxide...
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Arrhenius Acids and BasesAcids release hydrogen ions in water.Bases release hydroxide ions in water.
An acid is a substance that produces hydronium ions, H3O+, when dissolved in water.
Lewis DefinitionsA Lewis acid is a substance than can accept (and share) an electron pair.A Lewis base is a substance than can donate (and share) an electron pair.
Lewis Acid
Brønsted-Lowry DefinitionsA Brønsted-Lowry acid is a proton donor; it donates a hydrogen ion, H+.A Brønsted-Lowry base is a proton acceptor; it accepts a hydrogen ion, H+.
Brønsted-Lowry
Arrheniusacids
Acid Definitions
Acid Definitions
Lewis acids
Brønsted-Lowry
Arrheniusacids
The Arrhenius model of acidsand bases was broadened bythe Brønsted-Lowry model.
The Lewis acid-base model isthe most general in scope.
The Lewis definition of an acidincludes any substance thatis an electron pair acceptor;a Lewis base is any substancethat can act as an electron pair donor.
Ralph A. Burns, Fundamentals of Chemistry 1999, page 483
Lewis acids
Brønsted-Lowry
Arrheniusacids
The Arrhenius model of acidsand bases was broadened bythe Brønsted-Lowry model.
The Lewis acid-base model isthe most general in scope.
The Lewis definition of an acidincludes any substance thatis an electron pair acceptor;a Lewis base is any substancethat can act as an electron pair donor.
Ralph A. Burns, Fundamentals of Chemistry 1999, page 483
Acid Definitions
Acid – Base Systems
Type Acid Base
Arrhenius H+ or H3O + producer
OH - producer
Brønsted-
Lowry
Proton (H +) donor
Proton (H +) acceptor
Lewis Electron-pair acceptor
Electron-pair donor
Arrhenius Acid
1+
+ +
hydronium ion
H3O+
1-
chloride ion
Cl-
water
H2O
hydrogen chloride
HCl
(an Arrhenius acid)
Any substance that releases H+ ions as the only positive ion in the aqueous solution.
DefinitionsDefinitions
ArrheniusArrhenius - In aqueous solution… - In aqueous solution…
HCl + H2O H3O+ + Cl– •AcidsAcids form hydronium ions (H3O+)
H
HH H H
H
ClClO O
–+
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DefinitionsDefinitions
ArrheniusArrhenius - In aqueous solution… - In aqueous solution…
•BasesBases form hydroxide ions (OH-)
NH3 + H2O NH4+ + OH-
H
H
HH H
H
N NO O–+
H
H
H H
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Arrhenius Bases and Their Properties
According to the definition of Arrhenius a:
BaseBase - "a substance whose water solution yields...
Are NaOH and NH3 considered to be Arrhenius bases?
1) Bases are electroytes
Dissociation equation for NH3
NH3(g) + H2O(l) NH41+(aq) + OH1-(aq)
Dissociation equation for NaOH
NaOH(s) Na1+(aq) + OH1-(aq)
2) Bases cause indicatorsindicators to turn a characteristic color
3) Bases neutralize acidsNaOH(aq) + HCl(aq) NaCl(aq) + H2O(l)
YES
4) Water solutions of bases tasted bitter and feel slippery.
hydroxide ions (OH-) as the only negative ions."
Neutralization
NeutralizationNeutralization is a chemical reaction between an acid and a base to produce a salt (an ionic compound) and water.
NaOH(aq) + HCl(aq) NaCl(aq) + H2O(l)base acid salt water
Some neutralization reactions:
H2SO4(aq) + NaOH(aq) Na2SO4 + HOH
sulfuric acid sodium hydroxide sodium sulfate water
HC2H3O2(aq) + Ca(OH)2(aq) Ca(C2H3O2)2 + HOH
acetic acid calcium hydroxide calcium acetate water
2 2
2 2
NeutralizationNeutralization
ACID + BASE ACID + BASE SALT + WATER SALT + WATER
HCl + NaOH HCl + NaOH NaCl + H NaCl + H22OO
HCHC22HH33OO22 + NaOH + NaOH NaC NaC22HH33OO22 + H + H22OO
• Salts can be neutral, acidic, or basic.
• Neutralization does not mean pH = 7.
weak
strong strong
strong
neutral
basic
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ACID + BASE ACID + BASE SALT + WATER SALT + WATER
HCl + NaOH HCl + NaOH NaCl + H NaCl + H22OO
HCHC22HH33OO22 + NaOH + NaOH NaC NaC22HH33OO22 + H + H22OO
• Salts can be neutral, acidic, or basic.
• Neutralization does not mean pH = 7.
weak
strong strong
strong
neutral
basic
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Salts
SaltsSalts - Ionic compounds containing a positive ion other than the hydrogen ion and a negative ion other than the hydroxide ion.
i.e., a metal and a non-metal
Under what conditions do salts conduct current?
NaCl(s) + H2O(l) Na1+(aq) + Cl1-(aq)
Formulas and names of common salts
SALT FORMULA Common Name
sodium chloride NaCl (table) salt
sodium nitrate NaNO3 Chile saltpeter
sodium bicarbonate NaHCO3 baking soda
potassium carbonate K2CO3 potash
ammonium chloride NH4Cl sal ammoniac
NaCl
Salt Formation
NaOH HCl
strongbase
strongacid
salt of a strong base and a strong acidNaCl
NaOH HC2H3O2
strongbase
weakacid
salt of a strong base and a weak acidNaC2H3O2
Note: that in each case H-OH (water) is formed
NaOH + HCl NaCl + H2O
NaOH + HC2H3O2 NaC2H3O2 + H2O
Salt Formation
NH3H2SO4
weakbase
strongacid
salt of a weak base and a strong acid(NH4) 2 SO4
NH3HC2H3O2
weakbase
weakacid
salt of a weak base and a weak acidNH4 C2H3O2
Note: that in each case H-OH (water) is also formed
NH4OH H2SO4
NH4OH + H2SO4 (NH4)2SO4 + H2O
NH4OH + HC2H3O2 NH4C2H3O2 + H2O
NH3H2SO4
weakbase
strongacid
salt of a weak base and a strong acid(NH4) 2 SO4
NH4OH H2SO4
ammonium ion
NH4+
hydroxide ion
OH-
1+ 1-
NH4+ OH-
1+ 1-
sulfuric acid
(NH4)2SO4
HOH
1+
HOH
1+
sulfate ion
2 NH4OH + H2SO4 (NH4)2SO4 + 2 HOH
waterammonium sulfate
2-
H2SO4
2 NH4OH + H2SO4 (NH4)2SO4 + 2 H2O
phosphoric acid ammonium hydroxide ammonium phosphate
Reactions that produce salt acid + base salt + water
H3PO4 NH4OH (NH4)3PO4 H2O
nitric acid magnesium hydroxide magnesium nitrateHNO3 Mg(OH)2 Mg(NO3)2 H2O
carbonic acid potassium hydroxide potassium carbonateH2CO3 KOH K2CO3 H2O
acetic acid aluminum hydroxide aluminum acetateHC2H3O2 Al(OH)3 Al(C2H3O2)3 H2O
perchloric acid barium hydroxide barium perchlorateHClO4 Ba(OH)2 Ba(ClO4)2 H2O
+ +and yields and water
Brønsted-Lowry Acids and Bases
1+
+
hydronium ion
H3O+
1-
chloride ion
Cl-
(base)
H2O
(acid)
HCl
+ -
Acid = any substance that donates a proton.
Base = any substance that accepts a proton.
Brønsted-Lowry Acids and Bases
1+
+
hydronium ion
H3O+
1-
chloride ion
Cl-
(base)
H2O
(acid)
HCl
+ -
Acid = any substance that donates a proton.
Base = any substance that accepts a proton.
Brønsted-Lowry Acids and Bases
(acid)
H2O
(base)
NH3
+-1+
+
ammonium ion
NH4+
1-
hydroxide ion
OH-
Brønsted-Lowry Acids and Bases
(acid)
H2O
(base)
NH3
+-1+
+
ammonium ion
NH4+
1-
hydroxide ion
OH-
Brønsted-Lowry Acids and Bases
1+
+
ammonium ion
NH4+
1-
hydroxide ion
OH-
(acid)
H2O
(base)
NH3
+-
Brønsted-Lowry Acids and Bases
1+
+
ammonium ion
NH4+
1-
hydroxide ion
OH-
(acid)
H2O
(base)
NH3
+-
DefinitionsDefinitions
Brønsted-LowryBrønsted-Lowry
HCl + H2O Cl– + H3O+
•AcidsAcids are proton (H+) donors.
•BasesBases are proton (H+) acceptors.
conjugate acidconjugate base
baseacid
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DefinitionsDefinitions
H2O + HNO3 H3O+ + NO3–
CBCAAB
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H
H
OH O
O
ON
Base Acid
DefinitionsDefinitions
Amphoteric - can be an acid or a base. - can be an acid or a base.
NH3 + H2O NH4+ + OH-
CA CBB A
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H
H
OH
N
Base Acid
H
H
DefinitionsDefinitions
F -
H2PO4-
H2O
HF
H3PO4
H3O+
Give the conjugate base for each of the following:
Polyprotic - an acid with more than one H - an acid with more than one H++
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DefinitionsDefinitions
Br -
HSO4-
CO32-
HBr
H2SO4
HCO3-
Give the conjugate acid for each of the following:
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DefinitionsDefinitions
LewisLewis• AcidsAcids are electron pair acceptors.
• BasesBases are electron pair donors.
Lewis base
Lewis acid
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