Review Charge Density FITCH Rules G1: Suzuki Is Success G2. Slow Me

Home , Amedeo Avogadro, Evangelista Torricelli, James Watt, Johannes Rydberg, Louis Harold Gray, Luigi Galvani

FITCH Rules “A” students work (without solutions manual) G1: Suzuki is Success ~ 10 problems/night. G2. Slow me down G3. Scientific Knowledge is Referential General Dr. Alanah Fitch G4. Watch out for Red Herrings Flanner Hall 402 G5. Chemists are Lazy 508-3119 ⎛qq12 ⎞ [email protected] Ek= ⎜ ⎟ C1. It’s all about charge el ⎝ + ⎠ rr12 Office Hours Th&F 2-3:30 pm C2. Everybody wants to “be like Mike”

⎛qq12 ⎞ C3. Size Matters Ek= ⎜ ⎟ el ⎝ + ⎠ rr12

Module #17A: Chemistry C4. Still Waters Run Deep Piranhas lurk Acid Base Visualization C5. Alpha Dogs eat first Review Charge What is an alpha dog? Density High charge, low volume

9 Jm It’s all about charge kx= 899. 10 2

C Galen, 170 Marie the Jewess, 300 Jabir ibn Galileo Galili Evangelista Torricelli Jean Picard Daniel Fahrenheit Blaise Pascal Robert Boyle, Isaac Newton Anders Celsius Charge on object 1 or 2, in coulombs Hawan, 721-815 An alchemist 1564-1642 1608-1647 1620-1682 1686-1737 1623-1662 1627-1691 1643-1727 1701-1744 ⎛qq12 ⎞ Energy= k ⎜ ⎟ Distance between the objects electrostatic ⎝ d ⎠

Charles Augustin James Watt Luigi Galvani Count Alessandro G Amedeo Avogadro John Dalton William Henry Jacques Charles Georg Simon Ohm Michael Faraday B. P. Emile Germain Henri Hess Coulomb 1735-1806 1736-1819 1737-1798 A A Volta, 1747-1827 1756-1856 1766-1844 1775-1836 1778-1850 1789-1854 1791-1867 Clapeyron 1802-1850 1799-1864

r1 d r2 Dmitri Mendeleev Johannes D. J. Willard Gibbs Justus von Thomas Graham Richard AC E James Joule Rudolph Clausius William Thompson Johann Balmer Francois-Marie James Maxwell 1834-1907 Van der Waals 1839-1903 Liebig (1803-1873 1805-1869 Erlenmeyer (1818-1889) 1822-1888 Lord Kelvin, 1825-1898 Raoult 1831-1879 1837-1923 1825-1909 1824-1907 1830-1901

rr12+

Gilbert N Johannes Lawrence Henderson Niels Bohr Erwin Schodinger Louis de Broglie Friedrich H. Hund Rolf Sievert, Fritz London Wolfgang Pauli Werner Karl Linus Pauling Louis Harold Gray Lewis Bronsted 1878-1942 1885-1962 1887-1961 (1892-1987) 1896-1997 1896-1966 1900-1954 1900-1958 Heisenberg 1901-1994 1905-1965 1875-1946 1879-1947 1901-1976 ⎛qq12 ⎞ Ek= ⎜ ⎟ el ⎝rr+ ⎠ 12Coulomb’s Law Review: Module 5 Fitch Rule G3: Science is Referential 1 It Takes energy to push these guys together Effect of ionic charge Repulsion repulsive 7.00E-14 3.00E+05 7.00E-14 M4+---M4+ As Charge increases M4+---M4+ The repulsive energy of like charged Positive 6.00E-145.00E-14 Or attractive energy of differently charged energy2.00E+05 M+3—M3+ Ions increases + It’s all about charge + 5.00E-143.00E-14 +1 charged ions are “losers” compared to more 1.00E+05 M+2—M2+ highly charged ions 4.00E-141.00E-14 M+3—M3+

0.00E+00 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 02468101214 -1.00E-143.00E-14 M-2—M2+ kJ/mole of charges -1.00E+05 2.00E-14 -3.00E-14 M+2—M2+ -3 3+ Electrostatic Interaction Energy (J) Energy Interaction Electrostatic ElectrostaticElectrostatic Interaction Interaction Energy Energy (J) (J) Electrostatic Interaction Energy (J) M —M Electrostatic Interaction Energy (J) Energy Interaction Electrostatic 1.00E-14 -2.00E+05 -5.00E-14 1+ +1 - M4----MM4+--M Attraction + 0.00E+00 -7.00E-14 -3.00E+05 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 Radius of ion (pm) nm distance attractive Radius of ion (pm) Negative ⎛qq12 ⎞ Ek= ⎜ ⎟ energy el ⎝ + ⎠ Review: Module 5 rr12

Are there differences in predicted electrostatic effect? Ion Symbol Charge Radius (pm) Charge/radius 7.00E-14 hydrogen D+ 1 4 0.25 Energy of attraction of differently charged ions H+ should lithium Li+ 1 1 89.66666667 0.011152416 Or energy of repulsion of same charged ions behave 5.00E-14 sodium Na+ 1 127.4285714 0.007847534 Decreases differently With increasing size of ion potasium K+ 1 164 0.006097561 Size Matters cesium Cs+ 1 192.8333333 0.005185825 3.00E-14

beryllium Be2+ 2 59 0.033898305 Be2+ and Mg2+ 1.00E-14 magnesiumMg2+ 2 85 0.023529412 should behave calcium Ca2+ 2 129.5 0.015444015 differently 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 strontium Sr2+ 2 143.3333333 0.013953488 -1.00E-14 barium Ba2+ 2 149 0.013422819

oxide O2- -2 124.2 -0.01610306 2- 2- -3.00E-14 O and, maybe, S sulfide S2- -2 170 -0.011764706 should behave Electrostatic Interaction Energy (J) selenide Se2- -2 184 -0.010869565 differently -5.00E-14 telluride Te2- -2 207 -0.009661836

fluoride F- -1 116.625 -0.008574491 F- should -7.00E-14 chloride Cl- -1 167 -0.005988024 behave Radius of ion (pm) bromide Br- -1 182 -0.005494505 differently ⎛qq12 ⎞ iodine I- -1 206 -0.004854369 ⎛qq12 ⎞ Ek= ⎜ ⎟ Ek= ⎜ ⎟ el ⎝ + ⎠ el ⎝ + ⎠ Review: Module 5 rr12 Review: Module 5 rr12 2 D+ Some 0.04 Common Be2+ anions 0.03

Mg2+ 0.02

Li+ 0.01

0 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 2.5 Charge/(average ionic radius) ionic Charge/(average Charge/(average ionic radius) ionic Charge/(average

F- -0.01 O2 - -0.02 Which is ⎛ q ⎞ Some of the points don’t fall Charge on ion ⎜ 1 ⎟ ⎝ ⎠ Within a “cluster” Alpha? r1 Review: Module 5 http://www.chemistry.wustl.edu/~courses/genchem/Tutorials/Ions/ions.html

“A” students work (without solutions manual) ~ 10 problems/night.

Dr. Alanah Fitch Flanner Hall 402 508-3119 [email protected]

Office Hours Th&F 2-3:30 pm Low charge Charge is Module #17A: Density Distributed Acid Base Visualization NOT an Throughout Review Biological Alpha dog The volume Dependence on

Review: Module 5 Acid/base reactions 3 H and salt bonding in : ALAdehydratase 2 ALAD 2 Pb catalyst 1

4 Pb

3D structure of ALAD directs Reactants into proper orientation Review Acid Base Definitions: Module 6 hemoglobin 3D structure controlled by proper hydrogen and ionic bonds, pH dependent!!!!!!!

2+ 1 Larger Pb ion distorts the ALAD ALA builds up structure prevents biocatalytic function S - O

S - Pb2+ HS OH Zn2+ NH2 cys S - 2 S -

Ionic bond C Oh, Card me PleaSe O Acts like GABA O C - O - OH- O Distorts: 2+ CO 2- S- H Pb Neural signaling 3 Neural development 3- PO4 - S2- S (insoluble) H bonding possible Charge is due to ACID/BASE chemistry Review Acid Base Definitions: Module 6 4 Acid base reactions RNH33+ → RN+ H+ With N and COOH, C-OH ← “A” students work Control charge sites on Proteins, allowing folding N N (without solutions manual) + N N +H+ ~ 10 problems/night. H

Dr. Alanah Fitch Flanner Hall 402 508-3119 [email protected]

Office Hours Th&F 2-3:30 pm

Module #17A: Acid Base Visualization Review Acid/base definitions Hemeglobin

Acid-Base Definitions Acid is a sour taste

Hard soap

NaOH (lye) Soft soap + Or KOH (pot ash) Ca(OH)2 (lime)

saponification

Bases Latin for soap dissolve fatty acids and oils Foliate papillae are situated on the edge of the tongue slightly anterior of the circumvallate line. They are predominantly sensitive to sour tastes. Innervated from your by the glossopharyngeal (lXth cranial) nerve. On average 5.4 foliate papillae per skin, making side of the tongue, 117 taste buds per foliate papillae, total = 1280 foliate taste soaps (feel buds per tongue. slippery) 5 In 1849 a Harvard chemistry professor, John Webster argued with a colleague, Dr. Chemical Definition of Acid/Base Parkman, about money he owed the colleague for some dinosaur bones. He killed his fellow Professor and attempted to hide the crime by dissolving the body in a vat Svante Arrhenius Of “lime” (Ca(OH)2) and then burning the remaining bones. An acid is a species that produces proton ions in solution

X- or A- is an anion who Solution is partnered with the cation, H+

Acid: HX +− HXaq→+ H aq X aq

+− HA→+ H A Strong Weak aq aq aq acid acid

In a STRONG acid the anion can not provide enough electrostatic attraction to hold onto the H+ (proton) In a WEAK acid the anion is very charge dense and holds onto the H+ Review Acid Base Definitions: Module 6

Some

Galen, 170 Marie the Jewess, 300 Jabir ibn Galileo Galili Evangelista Torricelli Jean Picard Daniel Fahrenheit Blaise Pascal Robert Boyle, Isaac Newton Anders Celsius Hawan, 721-815 An alchemist 1564-1642 1608-1647 1620-1682 1686-1737 1623-1662 1627-1691 1643-1727 1701-1744 Common anions

Dmitri Mendeleev Johannes D. J. Willard Gibbs Justus von Thomas Graham Richard AC E James Joule Rudolph Clausius William Thompson Johann Balmer Francois-Marie James Maxwell 1834-1907 Van der Waals 1839-1903 Liebig (1803-1873 1805-1869 Erlenmeyer (1818-1889) 1822-1888 Lord Kelvin, 1825-1898 Raoult 1831-1879 1837-1923 1825-1909 1824-1907 1830-1901

Fitch Rule G3: Science is Referential http://www.chemistry.wustl.edu/~courses/genchem/Tutorials/Ions/ions.html 6 Who gives up and who holds onto a proton? Low Charge Density Intermediate Charge Density We saw that q/r > ~0.08 seemed to be “big” High Charge Density Which of these anions are not “alpha dogs” No Clean Socks Oh Card me PleeeeaSe!! name formula charge radius charge/radius No perchlorate ClO4- 1 236 0.004237288 - - - OH- CO 2- PO 3- S2- NO3 Cl HSO4 3 4 Clean nitrate NO3- 1 189 0.005291005 Socks bromide Br- 1 182 0.005494505 H+ Low Charge Density High Charge Density chloride Cl- 1 167 0.005988024 H2O HSO4- 1 ? ? Anions Give up protons Anions hold onto protons H2PO4- 1 ? ? hydrogen sulfide HS- 1 ? ? STRONG acids WEAK acids HPO42- 2 ? ? hydrogen carbonate HCO3- 1 163 0.006134969 Weak to acetate CH3COO- 1 159 0.006289308 Intermediate Oh formate HCOO- 1 158 0.006329114 +− → +− nitrite NO2- 1 155 0.006451613 HXaq→+ H aq X aq HX← H+ X Card aq aq aq hydroxide OH- 1 140 0.007142857 Completely falls apart Me fluoride F- 1 116.625 0.008574491 X- tries to hold onto some protons; PleaSe sulfate SO42- 2 230 0.008695652 are “alpha dogs” carbonate CO32- 2 185 0.010810811 Double arrow → +− sulfide S2- 2 170 0.011764706 HO← H+ OH 2 l aq aq phosphate PO43- 3 238 0.012605042 Review Acid Base Definitions: Module 6 Water is an Arrhenius acid

Another very common type of Weak Acid - ….COOH Some Weak Acids with COO- functional group (Carboxylate)

O C - O Formic Acid Acetic Acid Butanoic Acid S - H (Ants) Vinegar HOAc (OAc = acetate) Gives Condensed Structural Formula gives a clue as to the Smell of Important Functional Group Rancid Blue represents negative charge O OH H3C O O butter causes potential field HCOOH HCOOH What do you see? Is the negative charge fully localized? OH H3C OH O HCOOH CH COOH 3 CH3CH2CH2COOH O H C Dissociate temporarily

Proton actually resides H H H Somewhere between Two highly negatively Charged oxygen

Will Be Used Over and Different modeler Review Acid Base Definitions: Module 6 Gave opposite color scheme (Red = large neg charge) Over In Example Problems http://academic.reed.edu/chemistry/alan/ED/JCE/figlist.html 7 Strong Bases (SB) Chemical Definition of Acid/Base hydroxides which have low charge density cations as partners

Svante Arrhenius ⎛qq12 ⎞ Ek= ⎜ ⎟ el ⎝ + ⎠ rr12 An acid is a species that produces proton ions in solution A base is a species that produces hydroxide ions in solution 1. q is low (+1) Group 1 (Li+, Na+, K+) Solution −+ MOH→+ OHaq M aq completely +− LiOH⎯→⎯⎯⎯⎯⎯+ Liaq OH aq Acid: HX Base: 2. r is large Group 2 cations 2+ Strong Weak Strong Be But only larger ones acid acid base Mg2+ Ca2+ Not Ra2+ because dispersion forces come into play Sr2+ 2+ completely 2 +− Ba Ca() OH⎯→⎯⎯⎯⎯⎯+ Ca2 OH Where M+ is some cation Ra2+ 2 aq aq Review Acid Base Definitions: Module 6

Who gives up and who holds onto a hydroxide? Low Charge Density Intermediate Charge Density High Charge Density “A” students work No Clean Socks Oh Card me PleeeeaSe!! (without solutions manual) ~ 10 problems/night. - - - OH- CO 2- PO 3- S2- NO3 Cl HSO4 3 4

H+ STRONG acids WEAK acids Dr. Alanah Fitch Flanner Hall 402 Group 1 cations (1+) 508-3119 [email protected] Strong Bases Group 2 cations (2+) Office Hours Th&F 2-3:30 pm

Module #17A: Acid BaseVisualization Weak bases are produced by an alternative manner Our next step is to look Review More Acid Base Definitions Review Acid Base Definitions: Module 6 To an alternative definition

8 Bronsted and Lowry definitions

- - Galen, 170 Marie the Jewess, 300 Jabir ibn Galileo Galili Evangelista Torricelli Jean Picard Daniel Fahrenheit Blaise Pascal Robert Boyle, Isaac Newton Anders Celsius B and X are bases (anions) which can accept protons Hawan, 721-815 An alchemist 1564-1642 1608-1647 1620-1682 1686-1737 1623-1662 1627-1691 1643-1727 1701-1744 −+→ BHHBaq+ aq← aq

−+→ Charles Augustin James Watt Luigi Galvani Count Alessandro G Amedeo Avogadro John Dalton William Henry Jacques Charles Georg Simon Ohm Michael Faraday B. P. Emile Germain Henri Hess Coulomb 1735-1806 1736-1819 1737-1798 A A Volta, 1747-1827 1756-1856 1766-1844 1775-1836 1778-1850 1789-1854 1791-1867 Clapeyron 1802-1850 XHHXaq+ aq← aq 1799-1864 HX and HB are species which can donate protons → −+ Dmitri Mendeleev Johannes D. J. Willard Gibbs HX← X+ H Justus von Thomas Graham Richard AC E James Joule Rudolph Clausius William Thompson Johann Balmer Francois-Marie James Maxwell 1834-1907 Van der Waals 1839-1903 aq aq aq Liebig (1803-1873 1805-1869 Erlenmeyer (1818-1889) 1822-1888 Lord Kelvin, 1825-1898 Raoult 1831-1879 1837-1923 1825-1909 1824-1907 1830-1901 → −+ HBaq← B aq+ H aq

Ludwig Boltzman Henri Louis Henri Bequerel Jacobus van’t Hoff Johannes Rydberg J. J. Thomson Heinrich R. Hertz, Max Planck Svante ArreheniusWalther Nernst Marie Curie Fritz Haber Thomas M Lowry 1844-1906 LeChatlier 1852-1908 1852-1911 1854-1919 1856-1940 1857-1894 1858-1947 1859-1927 1864-1941 1867-1934 1868-1934 1874-1936 1850-1936 −++ → BHHBaq aq← aq A proton donor → −+ Bronsted acid HXaq← X aq+ H aq Gilbert N Johannes Lawrence Henderson Niels Bohr Erwin Schodinger Louis de Broglie Friedrich H. Hund Rolf Sievert, Fritz London Wolfgang Pauli Werner Karl Linus Pauling Louis Harold Gray Lewis Bronsted 1878-1942 1885-1962 1887-1961 (1892-1987) 1896-1997 1896-1966 1900-1954 1900-1958 Heisenberg 1901-1994 1905-1965 A proton acceptor 1875-1946 1879-1947 1901-1976 − ++→ − BHXHBXaq aq← aq aq (Bronsted base) Fitch Rule G3: Science is Referential

1. Write the linking rx 2. Identify the mass balance component BHHB−++ → aq aq← aq Example: Mass balance for B What is conjugate base of: 1. Occurs as both a “base” and “acid” form +− HClO→+ H ClO HClO4 2. The 2 forms are “linked” by the reaction 44,,aq aq aq +− H2O HO2 laqaq→+ H OH, Linking 3. The 2 forms are “conjugated” reactions + PH4 - ++ 4. The anion B is the “conjugate” base of HB PH43→+ Haq PH → −+ Mass balance component HXaq← X aq+ H aq What is conjugate acid of: Mass balance for X −+ - CN,aq+→ H aq HCN aq CN 1. Occurs as both a “base” and “acid” form −+ −Linking 2- SO2 +→ H HSO SO 2. The 2 forms are “linked” by the reaction 4,,aq aq4 aq reactions 4 3. The 2 forms are “conjugated” 4. The HX is the conjugate acid of X- 9 conjugate base charge radius charge/radius conjugate acid ClO4- 1 236 0.004237288 HClO4 In every Bronsted-Lowry Acid-base reaction NO3- 1 189 0.005291005 HNO3 Br- 1 182 0.005494505 HBr the position of the equilibrium favors transfer of Cl- 1 167 0.005988024 HClO4 the proton to the stronger base. HSO4- 1 ? ? H2SO4 H2PO4- 1 ? ? H3PO4 HS- 1 ? ? H2S HPO42- 2 ? ? H2PO4- HCO3- 1 163 0.006134969 H2CO3

CH3COO- 1 159 0.006289308 H(CH3COO) q1 q1 ↑↑↑> ↑ HCOO- 1 158 0.006329114 H(HCOO) r r NO2- 1 155 0.006451613 HNO2 1 1 OH- 1 140 0.007142857 HOH Get proton F- 1 116.625 0.008574491 HF q1 q ↑ > 1 SO42- 2 230 0.008695652 HSO4- ↓ r1 CO32- 2 185 0.010810811 HCO3- r1 S2- 2 170 0.011764706 HS- PO43- 3 238 0.012605042 HPO42- Alpha dogs eat first Notice, that some anions occur in multiple rx

Predict who gets the proton B- or X- : Water can be one of the conjugate pairs − → − BHXHBXaq++ aq← aq aq → +− HXaq← H aq+ X aq

q + → + q1 1 HO+ H HO ↓ ↑ 23l aq← aq r1 r1 +− Oh HO++ HX→ HO X Cl- OH- 23l aq← aq aq H Br- N ••O •• O I- H - 2- Card (me) The acid HX donates a proton to water No NO3 CO3 - -3 P(lea) Clean ClO4 PO4 it is a proton donor = acid - -2 S(e) Socks HSO4 S The water molecule takes a proton from HX H2O it is a proton acceptor = base -3 Water PO4 Is Neither one intermediate Water is a Bronsted-Lowry Base

10 We looked at 2 water reactions Weak bases are made by a BL reaction with water

→ +− RHORHOH++← 2 l aq aq → +−Acts as Arrhenius Acid HO← H+ OH 2 l aq, aq source of protons +− NH++ H O→ NH OH + → + 32()aql ← 4 () aq aq HO+ H← HO Acts as Bronsted-Lowry Base 23l aq, aq proton acceptor → +− HO++ HO← HO OH 223llaq, aq Base 2 Acid 2 Who is a proton donor (BL acid)? Water

Acid 1 Base 1 Who is a proton acceptor (BL base)? Ammonia The ability of water to act as both acid/base Is called amphoteric What functional groups are “R”?

http://core.ecu.edu/phys/flurchickk/AtomicMolecularSystems/molecularStructures/molecularStructures.html

Write reaction to show the unbonded electrons on R (where R is N in ammonia) net neutral Molecule ammonia, NH3

Is the charge evenly distributed? −+ HO2 +→: R OHaq RH+ aq Is there a region of high charge Density? Write the reaction to show that electrons on R are attracted to proton on water In this model blue is negative charge causing a potential field −+ and red is Positive charge HO⋅⋅ H: + R → OHaq RH aq + opposite potential field

+− → +−RHORHOH+→ + NH32++ H O← NH 4 OH 2 aq aq

Compounds in which H on NH3 has been replaced by –C groups react Nitrogen typically contains a set of unbonded electrons Similarly NH3 CH3NH2 which give Large charge density near the N atom R C2H5NH2 (C2H5)2NH C H NH Review Acid Base Definitions: Module 6 6 5 2

11 http://www.chem.uic.edu/web1/PDF/CH13.PDF

NH3

→ +− NH32++ H O← NH 4 OH N

C C C CH NH 3 2 C C C → +− CH32 NH++ H 2 O← CH 33 NH OH

In this image electrons are red → +− (CH) NH++ H O←( CH) NH OH 3 2 232 2 aniline

(CH65) NH 2

(CH3)2NH

→ +− (CH65) NH 2++ HO 2←( CH 65) NH 3 OH

2 There is one more type of acid/ 1 Base reaction to consider

Solution

Acid: HX Base:

Strong Weak Strong Weak acid acid base base −+ +− MOH→+ OHaq M aq RHORHOH+→2 aq aq + 3D structure of ALAD directs Bronsted Lowry Arrhenius Reactants into proper orientation proton acceptor (base) hydroxide donor Review Acid Base Definitions: Module 6 - + 3D structure controlled by proper ionization of COO and RNH3 (base) 12 Lewis Acids and Bases: “A” students work Base is an electron pair donor (without solutions manual) Lewis acid is an electron-pair acceptor; ~ 10 problems/night.

Dr. Alanah Fitch Flanner Hall 402 508-3119 [email protected]

Office Hours Th&F 2-3:30 pm

Module #17A: Acid Base Visualization Not proton donor! One more kind of Acid/Base reaction

⎛qq12 ⎞ Highly chared Ek= ⎜ ⎟ el ⎝rr+ ⎠ Cations can 12 Act as Lewis 3+ 2 + q ↑ → + acids FeHO()++ HO← FeOHHO()( ) HO = stronger effect 2 6()aq22l 5 () aq 3 r ↓

•• ⎡ •• ⎤ 33+ • ⎢ + • ⎥ + Al+⋅⋅→• O HAlOHH• ⋅⋅⋅⋅⋅aq + ⎣⎢ ⎦⎥ H

Aluminum ion is an electron pair acceptor = Lewis acid 13 ATOM SIZE (NOT ION) Size (A) 1.34 1.74 1.31 1.18 “A” students work (without solutions manual) Charge +1 +2 +2 +3 ~ 10 problems/night. Charge/size 0.75 1.15 2.30 3.39

Dr. Alanah Fitch Flanner Hall 402 Produce protons 508-3119 [email protected]

Office Hours Th&F 2-3:30 pm

Module #17A: Acid BaseVisualization

Salts

Ionic salts can act as acids and bases Predict what happens when the following salts +− MXsaqaq→+ M X Are added to water Na+ Cl- −−−−() n n1 Require + XHOHXOHaq +→2 aq +aq Na does not “grab” OH from water, no effect High charge Bronsted-Lowry Base Cl- does not “grab” H from water, no effect Density neutral •• ⎡ •• ⎤ 33+ • + • ions+ Al+⋅⋅→• O HAlOHH⎢ • ⋅⋅⋅⋅⋅⎥ + + - ⎢ aq ⎥ NH4 Cl Arrhenius Acid: forms ⎣ ⎦ protons Lewis Acid ++acidic H NH42,,aq+→ H O NH 323 aq H + O q

3+ ()n 1 −+ + MHOMOHH+→2 () aq + l + - Bronsted Lowry Base: Generic Lewis Acid Na CH3COO Proton acceptor

−− ++ basic CH323 COOaq+→ H O CH COOH aq OH q + NH42,,aq+→ H O NH 323 aq H + O q l Arrhenius acid

14 FITCH Rules What about NH4F? Arrhenius Acid: forms protons + → + G1: Suzuki is Success NH++ HO← NH HO acidic 42,,aql 323 aq q G2. Slow me down − → −Bronsted Lowry Base: FHOHFOH++← G3. Scientific Knowledge is Referential aq2 l aq aq Proton acceptor General G4. Watch out for Red Herrings basic G5. Chemists are Lazy ⎛qq12 ⎞ Ek= ⎜ ⎟ C1. It’s all about charge el ⎝ + ⎠ rr12 Who controls the pH? C2. Everybody wants to “be like Mike” ⎛qq12 ⎞ C3. Size Matters Ek= ⎜ ⎟ el ⎝ + ⎠ rr12 Chemistry C4. Still Waters Run Deep Piranhas lurk Here we need to define one of our C5. Alpha Dogs eat first comparison numbers

Definition of Ka Definition of Kb “a” stands for “acid dissociation” −+ “b” stands for “base reaction” [ AHOaq][ 3 aq] +−[] HO+→ HA HO A +KMKeq55 ==[] a +− 23l aq, aq aq RHORHOH+→ + HAaq 2 aq aq

−+ [][]AHO3 +− aq aq −+ []RH[ OH] K = AHO aq aq eq [] [ aq][ 3 aq] K = = eq HAaq [] H2 O []Ka RHO l [][]2 HAaq

Density of water is 1 g/mL +− What is the molarity of liquid water? [ RH][aq OH] aq KHOK[]== eq2 b []R 3 3 ⎛⎛11gHgH O O 10⎞10⎞⎛⎛mLmL 1mole1mole⎞⎞⎛⎛ H H O O ⎞⎞ ⎜⎜ 2 2 ⎟⎟⎜⎜ ⎟⎟⎜⎜ 2 2 ⎟⎟ = ⎝⎝ ⎠⎠⎝⎝ ⎠⎠⎝⎝ 5555. ⎠M⎠ mLmL LL 1818gHgH2 2 O O +− []RHaq[ OH] aq K = b []R

15 What about NH4F? What about NH4ClO?

++ ++ NH+→ H O NH H + O −10 NH+→ H O NH H + O −10 42,,aq 323 aq q Kxa = 56. 10 42,,aq 323 aq q Kxa = 56. 10

− → − −11 − → − −7 FHOHFOH++← Kxb = 14. 10 ClO++ H O← HClO OH Kxb = 36. 10 aq2 l aq aq aq2 l aq aq Who controls the pH? Who controls the pH?

+ - Reaction with largest Keq Since the concentrations of NH4 and F are equal the will be in control reaction with the largest Keq ClO- controls, solution goes basic

Ammonium controls, solution goes acidic

conjugate base charge radius charge/radius conjugate acid Ka “A” students work ClO4- 1 236 0.004237288 HClO4 (without solutions manual) NO3- 1 189 0.005291005 HNO3 ~ 10 problems/night. Br- 1 182 0.005494505 HBr Cl- 1 167 0.005988024 HClO4 HSO4- 1 ? ? H2SO4 H2PO4- 1 ? ? H3PO4 0.01 HS- 1 ? ? H2S 1.0X10-7 Dr. Alanah Fitch HPO42- 2 ? ? H2PO4- 6.1X10-8 Flanner Hall 402 HCO3- 1 163 0.006134969 H2CO3 4.4x10-7 508-3119 CH3COO- 1 159 0.006289308 H(CH3COO) 1.8x10-5 [email protected] HCOO- 1 158 0.006329114 H(HCOO) 1.9x10-4 NO2- 1 155 0.006451613 HNO2 6.0x10-4 Office Hours Th&F 2-3:30 pm OH- 1 140 0.007142857 HOH 1.OX10-14 F- 1 116.625 0.008574491 HF 6.9x10-4 SO42- 2 230 0.008695652 HSO4- 0.01 Module #17A: CO32- 2 185 0.010810811 HCO3- 4.7x10-11 Acid BaseVisualization S2- 2 170 0.011764706 HS- 1.2x10-13 PO43- 3 238 0.012605042 HPO42- 4.5x10-13 Using Ka and Kb Values for comparison

16 ? +− HO++ HA→ HO A 23l aq← , aq aq ? Electronegativity Who will the proton, “A” or water? Cl A water K − H a - ⎡ O•• ⎤ ⎢ • • ⎥ N HSO ⎢ • • ⎥ •• •• Huge 4 ⎢ •• ⎥ •• ⎢• O S OH ⎥ O ⎢• − − − ⎥ ⎢ •• •• ⎥ ⎢ • • ⎥ O ⎢ O• • ⎥ H •• ⎣⎢ − •• ⎦⎥ H • O • ⎡ • • ⎤ N -⎢ ⎥ •• -4 NO ⎢ ⎥ •• 2 •• •• O 4x10 ⎢ HO−− N O =⎥ -9 ⎢ •• •• ⎥ O Ka= 2.5x10 ⎢ ⎥ Br • • H ⎢ ⎥ •O • H ⎢ ⎥H ⎣ ⎦ •• • •• N -5 - HC−−C −O • 1.8x10 CH3COO •• •• O HBrO EN = 2.8 H O HH •• -10 • • •• N 5.6x10 HN• •H •• NH3 •• O H O H I What do you observe? How does Ka change with structure? This kind of question WILL be on exam What do you observe?

Acid-Base Behavior and Chemical Structure Which is strongest acid and why?

1.8x10-4

Ka = 1.8x10-5

Additional O pull e from Cl which in turn pulls e from OH group

6.3x10-5

17 14_02T

Values of Ka for Some Common Monoprotic Acids Values of Kb for Some Common weak bases

Formula Name Value of Ka* Formula Name Value of Kb*

− −2 − -12 HSO4 Hydrogen sulfate ion 1.2 x 10 SO4 sulfate ion 1.0 x 10 HClO Chlorous acid 1.2 x 10−2 1.4x10-11 2 F- fluoride −3 -11 HC2H2ClO2 Monochloracetic acid 1.35 x 10 NO2- Nitrite 1.7x10 HF Hydrofluoric acid 7.2 x 10−4 −4 HNO2 Nitrous acid 4.0 x 10 −5 HC2H3O2 Acetic acid 1.8 x 10 C2H3O2- Acetate 5.6 x 10-10 3+ −5 [Al(H2O)6] Hydrated aluminum(III) ion 1.4 x 10 HOCl Hypochlorous acid 3.5 x 10−8 OCl- 3.6x10-7 HCN Hydrocyanic acid 6.2 x 10−10 CN cyanide 1.7x10-5 + −10 -5 Increasing basic strength basic Increasing NH4 Ammonium ion 5.6 x 10 Increasing acid strength NH3 Ammonia 1.8x10 −10 -4 HOC6H5 Phenol 1.6 x 10 CO32- carbonate 2.1x10 PO423 phosphate 2.2x10-2 *The units of Kaare mol/L but are customarily omitted. *The units of Kbare mol/L but are customarily omitted. − −+ [ HA][ OH] [ AH][ ] − → − → −+ AHOHAOHKaq++2 ← aq aq base = HAaq← A aq+== H3 O aq K Acid Disociation K A l − []HA []Aaq

Blue is high electron density 4.38x10-4 “A” students work CH3NH2 (without solutions manual) → +− CH NH++ H O← CH NH OH 32 2 33 ~ 10 problems/night.

Color change to red Explain Dr. Alanah Fitch NH -5 Flanner Hall 402 This 3 1.8x10 508-3119 → +− [email protected] NH++ H O← NH OH trend 32 4 Office Hours Th&F 2-3:30 pm

(CH) NH N 65 2 Module #17A: -10 C 3.8x10 Acid BaseVisualization C C → +− (CH) NH++ HO←( CH) NH OH C C 65 2 2 65 3 C Polyprotic acids Color change (red=electrons) Electrons can get “shoved” back onto molecule 18 Polyprotic acids can supply more than 1 proton Predict who gets the proton:

→ +− HCO23aq, ← H aq+ HCO 3 aq n−−−−()n1 XHOHXOHaq +→2 aq +aq

− → +−2 HCO33aq← H aq+ CO aq

2- - SO4 HSO4 2- - Think about CO3 HCO3 2- - HPO4 H2PO4 q1 PO 3- HPO -2 4 4 r S2- HS- 1 Commonly: Ka1 >>> Ka2 which means commonly (but not always!) only the first one makes the proton contribution.

Tartaric acid; wine OH O Oxalic acid; rhubard O O Orders HO General Trend OH Of magnitude 1 O OH HO OH Difference Ka Ka1 vs Ka2? And Ka2 KKaa12 KK −−−2 2 aa12 ∞ −−−2 2 HSO24 HSO 4 12. x 10 SO4 HSO∞ HSO12. x 10 SO −−−−2 7 2 24 4 4 −−−−2 7 25 HPO33 10010.. x HPO23 2610 x HPO3 − − −− HPO33 10010.. x HPO23 2610 x HPO3 10 2 8 2 − 2 − 8−−24 HSO23 17.. x 10 HSO3 64 x 10 SO3 HSO17.. x 10 HSO 6 4 x 10 SO 10 − − − − 23 3 − 3 − 2 5 2 − − 2 HCOO()59.. x 10 HCO() 6 4 x 10 CO () () 2 5 3 22 2 2 2 2 HCOO2 2 59.. x 10 HCO()2 6 4 x 10 CO2 10 () − − − − 2 − 2 3 5 2 − − HCHO() COO10.. x 10 HCHO COO 4 () 6 x 10 CHO COO () ()3 ()5 2− 2 () 22 22 2 222 2 222 2 HCHO22 22 COO2 10.. x 10 HCHO222 COO2 4 6 x 10 CHO222 COO 2 10 7... 5x 10−−−−−3 H PO 6 2 x 108 HPO213 4 2 x 10 −−−−3 8 25 HPO3 4 24 4 HPO34 7.. 5x 10 HPO24 6 2 x 10 HPO4 10 − − − − −4 5 − 2 7 − − 4 − 5 2 1 H33 C OH 5() COO3 7... 4 x 10 H23 C OH 5 COO3 17 () x 10 HC35 OH COO3 4 0 x 10 () H C OH() COO7.. 4 x 10 H C OH COO 17 () x 10 HC OH COO 10 () −−−− 33 5 3 −−−−23 5 3 35 3 HCHO8.. 0 x 105 HCHO 16 x 10 12 CHO2 HCHO8.. 0 x 105 HCHO 16 x 1012 CHO27 10 26 66 −−666 −−666 26 66 −−−−666 666 HCO44510.. x7 HCO 56 x 10 11 CO2 7 11 24 23 −−3 3 HCO23 44510..− x HCO3 56 x 10 CO3 10 8 −15 8 −−15 7 HS2 57. x 10 HS 110.x HS2 57. x 10 HS110. x 10 Do you notice >K >K OH HO Ka1 a2 a3 Anything? O HO OH HO

OH What explains what is HO O O O OH O Happening? Ascorbic Acid; polar bear liver Citric acid; oranges 19 “A” students work (without solutions manual) ~ 10 problems/night.

Dr. Alanah Fitch Flanner Hall 402 508-3119 [email protected]

Office Hours Th&F 2-3:30 pm

Module #17A: Acid Base Visualization