Equilibrio ionico

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  • 1. EQUILIBRIO IONICO Equilibrio cido-base

2. ELECTROLITOS Son substancias que al disolverse en elagua se ionizan (disocian) +CIDOHCl H + Cl+ HCl + H2O H3O + Cl+BASENaOH Na + OH+SAL NaCl Na + Cl 3. C12H22O11 C12H22O11NaCl Na+ Na + Cl 4. CLASIFICACIN DE LOSELECTROLITOS Electrolito fuerte Electrolito dbilEs el que se disocia totalmente Es el que se disocia parcialmente + + CIDOHClH + ClCH3COOH CH3COO + H + + BASE NaOH Na +NH4OH NH4 + OH OH* todas las sales son +electrolitos fuertes SALNaCl Na + Cl 5. Grficoselectrolito fuerte y electrolitodbil 6. Electrolitos dbilesConstante de ionizacin ( Ki )HAc + H2O H3O+ + AcHAc H+ + AcKc = [H3O+][Ac]/ [HAc][H2O][H2O] = ctteKi = [H3O+][Ac] / [HAc]Ki = [H+][Ac] / [HAc] [H+] = Ki [HAc] 7. Tabla de las constantes de ionizacin 8. pH (potencial de hidrgeno) Es la medida de la concentracin molar de ioneshidrgeno en una solucin acuosa +pH = log [H ] 9. pH = log [ H+] HCl electrolito fuerte HClHCl HCl 1M 0.1M2M[ HCl ] = 1 [ H+] = 1 [ HCl ] = 0.1 [ H+] = 0.1 [ HCl ] = 2 [ H+] = 2 pH = -log 1 pH = -log 0.1 pH = -log 2 pH = 0pH = 1pH = 1.3 10. pH = log [ H+] CH3COOH electrolito dbilKi = 1.58 10-5CH3COOHCH3COOHCH3COOH 1M0.1M2M[H+] = 1.5810-5 x 1 [H+] = 1.5810-5 x 0.1 [H+] =1.5810-5 x 2 pH = -log (*)pH = -log (*)pH = -log (*)pH = 2.4pH = 2.9 pH = 2.25[H+] = Ka [cido] 11. pOH(potencial de oxidrilo) Es la medida de la concentracin molar de ionesoxidrilo en una solucin acuosa pOH = log [OH] 12. IONIZACIN DEL AGUA + H2O H + OH +Ki = [H ][OH]/ [ H2 O ] [H2O] = ctte +Ki [H2O] = [H ][OH]+ Kw = [H ][OH] Kw = producto inico del aguaKw = [H ][OH] = -log 110 pHK -7pH = 7[H+] = 110-7[OH] = 110-7+ -14 13. pH = log [ H+]NaOH electrolito fuerte NaOHNaOH NaOH1M 0.1M3M[ NaOH ]=1 [ OH]=1[ NaOH ]=0.1 [ OH]=0.1 [ NaOH]=3 [ OH]= 3Kw = [H+][OH] = 110-14 [H+][ 1 ] = 110-14[H+][ 0.1 ] = 110-14[H+][ 3 ] = 110-14[ H+] = 110-14 [ H+] = 110-13 [ H+] = 3.310-15pH = -log 110-14 pH = -log 110-13pH = -log 3.310-15 pH = 14pH = 13pH = 14.48 14. NH4OH electrolito dbilpH = log [ H ] + [OH] = Kb [Base]NH4OH NH4OHNH4OH 1M0.1M 3M[OH] = 1.5810-5 x 1[OH] = 1.5810-5 x 2 [OH] =1.5810-5 x 3 Kw = [H+][OH] = 110-14 [H+][OH ] = 110-14 [H+][OH ] = 110-14 [H+][OH ] = 110-14[ H+] = 2.5110-12 [ H+] = 1.7710-12[ H+] = 1.4510-12 pH = -log 2.5110-12 pH = -log 1.7710-12pH = -log 1.4510-12pH = 11.59 pH = 11.75pH = 11.83 15. +H2O H + OH+ Kw = [H ][OH] = 110-14 MEDIO CIDOCIDO HCl H+ + Cl MEDIO BSICOBASENaOH Na+ + OHMEDIO CIDO?SAL NaCl Na+ + ClMEDIO BSICO?MEDIO NEUTRO? 16. H2O H+ + OH+CIDOHCl H + Cl+BASE NaOH Na + OH+SALNaCl Na + ClCIDO FUERTEBASE FURTE 17. NH4ClHIDRLISIS + H2O H + OH +Kw = [H ][OH] = 110-14Es la reaccin de los iones de una sal con los iones del agua+CIDOHCl H + Cl +BASENH4OH NH4 + OH +SALNH4Cl NH4 + Cl+ la + OHH2O disminuyeH concentracin de OHaumenta la concentracin de H+CIDO FUERTE MEDIO CIDO 18. HIDRLISISCH3COONa +H2O H + OH+ Kw = [H ][OH] = 110-14Es la reaccin de los iones de una sal con los iones del agua+CIDOCH3COOH H + CH3COO +BASENaOH Na + OH + SALCH3COONa Na + CH3COO+ H2O H + OH +la concentracin de H disminuyeaumenta la concentracin de OH MEDIO BSICOCIDO DBIL 19. CLCULOS HIDRLISIS 20. EFECTO DEL ION COMN+Solucin bsica NH4OH NH4 + OH+ NH4Cl NH4 + Cl + H2O H H+ Si disminuye la concentracin de OH entonces se incrementa laOHconcentracin de H + , el pH disminuir 21. SOLUCIONES BUFFER