PSC 4010

PSC 4012Ionic Phenomena: A study of an environmental problem

PSC 4012: Neutralization & Indicatorsc(H+)pH = - log c(H+)Solution10-1 mol/L1Acid (H+)10-2 mol/L2Acid (H+)10-3 mol/L3Acid (H+)10-4 mol/L4Acid (H+)10-5 mol/L5Acid (H+)10-6 mol/L6Acid (H+)10-7 mol/L7Neutral (H2O)10-8 mol/L8Basic (OH-)10-9 mol/L9Basic (OH-)10-10 mol/L10Basic (OH-)10-14 mol/L14Basic (OH-)PSC 4012: Neutralization & IndicatorsAcids

Red and blue litmus paper turn RedArrhenius: acids release H+ when dissolved in Water (aqueous solution)

HF (l) + H2O H+(aq) + F-(aq)H2SO4 (l) + H2O 2H+(aq) + SO42-(aq)HI (l) + H2O H+(aq) + I-(aq)

PSC 4012: Neutralization & IndicatorsBases

Red and blue litmus paper turn BlueArrhenius: bases release OH- when dissolved in Water (aqueous solution)

NaOH (s) + H2O Na+(aq)+OH-(aq)Mg(OH)2 (s) + H2O Mg2+(aq)+ 2OH-(aq)NH4OH (l) + H2O NH4+(aq) + OH-(aq)

PSC 4012: Neutralization & IndicatorsSalts

Made of a metal ion and a non-metal ionRed and blue litmus paper turn do not change colourNeutral (pH = 7)Arrhenius: salts release ions other than H+ and OH- when dissolved in Water (aqueous solution)

NaCl (s)+H2O Na+(aq) + Cl-(aq)CaCl2 (s)+H2O Ca2+(aq) + 2Cl-(aq)AgNO3(s)+H2O Ag+(aq) + NO3-(aq)

PSC 4012: Neutralization & IndicatorsNeutralization:

PSC 4012: Neutralization & IndicatorsNeutralization:

PSC 4012: Neutralization & IndicatorsAcidic solution (pH = 1)Add NaOHpH increases (1 7)Neutral solution (pH = 7)Add NaOHpH increases (7 14)Basic solution (pH = 14)Add HClpH decreases (14 7)Neutral solution (pH = 7)Add HClpH decreases (7 1)Acid solution (pH = 1)

PSC 4012: Neutralization & IndicatorsPractice:

Ex. 6.15, p. 6.35Ex. 6.16, p. 6.35

PSC 4012: Neutralization & IndicatorspH

Property that distinguishes acidic, basic and neutral solutionsMeasures the concentration of H+ ions in solutionCan be determined by indicator, pH paper, pH meter, etc. pH scale: 0 14pH < 7 (Acidic solution: Acids)pH = 7 (Neutral solution: Salts)pH > 7 (Basic solution: Bases)

PSC 4012: Neutralization & IndicatorsIndicators:

What is an indicator?!

PSC 4012: Neutralization & IndicatorsIndicators:

PSC 4012: Neutralization & IndicatorsIndicators:

What is an indicator?!

Substance whose colour changes according to the level of pH of the solution that it is added toPSC 4012: Neutralization & IndicatorsIndicators:

PSC 4012: Neutralization & IndicatorsIndicators:

The change of colour occurs in a range of pH (turning point) that is particular for every indicator. Fig 5.8, p. 5.47Fig 5.9, p. 5.48

PSC 4012: Neutralization & IndicatorsPractice:

Ex. 5.34 & 5.35 p. 5.49