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Efnafræði sýra og basa – upprifjun. Sýrur og basar. Sýrur og basar. Sýrur og basar. Sýrur. Have a sour taste. Vinegar is a solution of acetic acid. Citrus fruits contain citric acid. React with certain metals to produce hydrogen gas .
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Sýrur Have a sour taste. Vinegar is a solution of acetic acid. Citrus fruits contain citric acid. React with certain metals to produce hydrogen gas. React with carbonates and bicarbonates to produce carbon dioxide gas Basar Have a bitter taste. Feel slippery. Many soaps contain bases.
Eignileikarsýra • Mynda H+ (as H3O+) jónir í vatni (the hydronium ion is a hydrogen ion attached to a water molecule) • Súrar á bragðið • Æta málma • Súrar vatnslausnir leiða rafmagn • Hvarfast við basa og mynda salt og vatn • pH undir 7
Nafnakerfisýra Binary Ternary
Nafnayfirlitsýra Review • HBr(aq) • H2CO3 • H2SO3 • H2SO4 Sulfuric acid hydrobromicacid carbonicacid sulfurousacid
Name ‘Em! • HI (aq)HydroIodic acid • HCl(aq) Hydrochloric acid • H2SO3 Sulfurous acid • HNO3 peIodic acid • HIO4 – perIodic acid
Eiginleikarbasa • MyndaOH-jónir í vatni • Beiskir á bragðið, chalky • Vatnslausnirbasaleiðarafmagn • Sápukenndir, sleipir • Hvarfastviðsýrurogmynda salt ogvatn • pH stærra en7
Algengirbasar NaOHnatriumhydroxíðlye - vítissódi KOH kalíumhydroxíð liquid soap Ba(OH)2 barium hydroxide stabilizer for plastics Mg(OH)2 magnesium hydroxide “MOM” Milk of magnesia Al(OH)3 aluminum hydroxide Maalox (antacid)
Sýra/basiskilgreiningar • Skilgreining #1: Arrhenius (traditional) Sýrur – mynda H+ jónir (or hydronium ions H3O+) Basar – mynda OH- jónir (problem: some bases don’t have hydroxide ions!)
Arrhenius sýra er efni sem myndar H+ (H3O+) in water Arrhenius basi er efni sem myndar OH- in water
Sýra/basiSkilgreiningar • Skilgreining#2: Brønsted –Lowry Sýra – Róteindagjafi Basi – Róteindaþegi Róteind er vetnisatóm sem hefur misst rafeindina sína!
A Brønsted-Lowrysýraróteindagjafi A Brønsted-Lowrybasiróteindaþegi Tilsvarandi sýra Tilsvarandi basi Basi sýra
Sýru/basaTeorian The Brønsted definition means NH3 is aBASEin water — and water is itself anACID
HONORS ONLY! Tilsvarandisýrurogbasar ! Finniðsýruna, basann, tilsvarandi (konjugered) sýruogtilsvarandibasa í efnhvörvunumhéraðneðan: HCl + OH- Cl- + H2O H2O + H2SO4 HSO4- + H3O+
Acid/Base Skilgreiningar Skilgr. #3 – Lewis Lewis sýra – Efnisemþiggurrafeindapar Lewis basi – efnisemgefurrafeindapar
Lewis Acids & Bases Myndunoxoníumjónarerágættdæmi. • Electron pair of the new O-H bond originates on the Lewis base.
Lewis Acid-Base Interactions in Biology • The heme group in hemoglobin can interact with O2 and CO. • The Fe ion in hemoglobin is a Lewis acid • O2 and CO can act as Lewis bases Heme group
pH skalinnsýnirstyrksýruogbasa. Í staðlítillatalnanotumviðnegatífttugveldafmólstyrkvetnisjóna.Under 7 = súrt 7 = hlutlaustOver 7 = basískt
Acidic solution [H+ ] > [OH- ] • Neutral solution [H+ ] = [OH- ] • Basic solution [H+ ] < [OH- ] Timberlake, Fig 9.3
Calculating the pH pH = - log [H+] (Remember that the [ ] mean Molarity) Example: If [H+] = 1 X 10-10pH = - log 1 X 10-10 pH = - (- 10) pH = 10 Example: If [H+] = 1.8 X 10-5pH = - log 1.8 X 10-5 pH = - (- 4.74) pH = 4.74
Try These! Find the pH of these: 1) A 0.15 M solution of Hydrochloric acid 2) A 3.00 X 10-7 M solution of Nitric acid
pH Útreikningar– FinnaH+ EfpH í Coke er3.12, [H+] = ??? AfþvípH = - log [H+] þá - pH = log [H+] Taka antilógaritma (10x) afbáðum: 10-pH =[H+] [H+] = 10-3.12 = 7.6 x 10-4 M *** Tilaðfinna antilog eða 10^x þáýtirþú Á shift hnappinnogsvo log
pH Útreikningar – Finna H+ • Lausnhefur pH of 8.5. hverermólstyrkurvetnisjóna í lausninni? pH = - log [H+] 8.5 = - log [H+] -8.5 = log [H+] Antilog -8.5 = antilog (log [H+]) 10-8.5 = [H+] 3.16 X 10-9 = [H+]
Meira um vatn Vatngeturvirkaðsemsýraogbasi. Vatnklofnar í jónir, slíktheitirsjálfsjónun. Jafnvægisfastivatnser= Kw Kw = [H3O+] [OH-] =1.00 x 10-14at 25 oC
Autoionization Kw = [H3O+] [OH-] = 1.00 x 10-14 at 25 oC Í hlutlausrilausner[H3O+] = [OH-] Kw = [H3O+]2 = [OH-]2 [H3O+] = [OH-] = 1.00 x 10-7 M
pOH –basastig • Since acids and bases are opposites, pH and pOH are opposites! • pOH does not really exist, but it is useful for changing bases to pH. • pOH looks at the perspective of a base pOH = - log [OH-] Since pH and pOH are on opposite ends, pH + pOH = 14
pH [H+] [OH-] pOH
[H3O+], [OH-] ogpH Hvaðer pH í 0.0010 M NaOHlausn? [OH-] = 0.0010 (or 1.0 X 10-3 M) pOH = - log 0.0010 pOH = 3 pH = 14 – 3 = 11 eðaKw = [H3O+] [OH-] [H3O+] = 1.0 x 10-11 M pH = - log (1.0 x 10-11) = 11.00
The OH- ion concentration of a blood sample is 2.5 x 10-7 M. What is the pH of the blood? The pH of rainwater collected in a certain region of the northeastern United States on a particular day was 4.82. What is the H+ ion concentration of the rainwater?
[OH-] 1.0 x 10-14 [OH-] 10-pOH 1.0 x 10-14 [H+] -Log[OH-] [H+] pOH 10-pH 14 - pOH -Log[H+] 14 - pH pH
Reiknið [H3O+], pH, [OH-], and pOH Problem 1: Efnafræðingur býr til : (a) 3.0 M og (b) 0.0024 M. Reiknið [H3O+], pH, [OH-], and pOH lausnanna við 25°C. Problem 2: Hvað er [H3O+], [OH-], og pOH lausnar með pH = 3.67? Er lausnin súr, basisk eða hlutlaus? Problem 3: Problem #2 með pH = 8.05?
Rammarogdaufarsýrur Römmsýra (sterk) klofnarauðveldlega í jónir (100% jónuð) HNO3, HCl, H2SO4 and HClO4 eru rammar sýrur.
Sýrumogbösumerskipt í tvennt: rammaogdaufa. Römmsýra: HNO3 (aq)+ H2O (l)H3O+ (aq) +NO3- (aq) HNO3 is about 100% dissociated in water.
Daufarsýrur (ogbasar) • Klofnaekki 100% í vatniog oft mjöglítiðþ.e. innanvið 1%. Sjáediksýru
CaO Rammirbasar • 100% klofnun í vatni. NaOH (aq) Na+ (aq) + OH- (aq) EinnigKOH andCa(OH)2. CaO (lime) + H2O --> Ca(OH)2 (slaked lime)
Daufirbasar • Minna en 100% jónaðir í vatnit.d. ammoníak NH3 (aq) + H2O (l) NH4+ (aq) + OH- (aq)
Jafnvægisýruogbasa Consider acetic acid, HC2H3O2 (HOAc) HC2H3O2 + H2O H3O+ + C2H3O2- Acid Conj. base (K erskrifað Kafor ACID) K gefurhlutfallklofið/óklofið í jónir
Sýrufastar / tilvarandibasafastar Conjugate Basi Sýra Increase strength Increase strength
Jafnvægi: daufsýra Daufsýrahefur Ka< 1 Leiðirtillágs[H3O+] og pH of 2 - 7
Jafnvægi: Basi Daufurbasihefur Kb< 1 Leiðirtillágs[OH-] ogpH of 12 - 7
Útreikn. viðjafnvægidaufsýra Þú hefur1.00 M HOAc. Reikniðjafnvægis-styrkHOAc, H3O+, OAc-ogpH. Step 1. [HOAc] [H3O+] [OAc-] initial change equilib 1.00 0 0 -x +x +x 1.00-xx x