1. PSC 4012 Ionic Phenomena: A study of an environmental problem

2. PSC 4012: Neutralization & Indicators c(H + )pH = - log c(H + )Solution 10 -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 (H 2 O) 10 -8 mol/L8Basic (OH - ) 10 -9 mol/L9Basic (OH - ) 10 -10 mol/L10Basic (OH - ) 10 -14 mol/L14Basic (OH - )

3. PSC 4012: Neutralization & Indicators Acids  Red and blue litmus paper turn Red  Arrhenius: acids release H + when dissolved in Water (aqueous solution) HF (l) + H 2 O H + (aq) + F - (aq) H 2 SO 4 (l) + H 2 O 2H + (aq) + SO 4 2- (aq) HI (l) + H 2 O H + (aq) + I - (aq)

4. PSC 4012: Neutralization & Indicators Bases  Red and blue litmus paper turn Blue  Arrhenius: bases release OH - when dissolved in Water (aqueous solution) NaOH (s) + H 2 O Na + (aq) +OH - (aq) Mg(OH) 2 (s) + H 2 O Mg 2+ (aq) + 2OH - (aq) NH 4 OH (l) + H 2 O NH 4 + (aq) + OH - (aq)

5. PSC 4012: Neutralization & Indicators Salts  Made of a metal ion and a non-metal ion  Red and blue litmus paper turn do not change colour  Neutral (pH = 7)  Arrhenius: salts release ions other than H + and OH - when dissolved in Water (aqueous solution) NaCl (s) +H 2 O Na + (aq) + Cl - (aq) CaCl 2 (s) +H 2 O Ca 2+ (aq) + 2Cl - (aq) AgNO 3(s) +H 2 O Ag + (aq) + NO 3 - (aq)

6. PSC 4012: Neutralization & Indicators Neutralization:

7. PSC 4012: Neutralization & Indicators Neutralization:

8. PSC 4012: Neutralization & Indicators  Acidic solution (pH = 1)  Add NaOH  pH increases (1 – 7)  Neutral solution (pH = 7)  Add NaOH  pH increases (7 – 14)  Basic solution (pH = 14)  Add HCl  pH decreases (14 – 7)  Neutral solution (pH = 7)  Add HCl  pH decreases (7 – 1)  Acid solution (pH = 1)

9. PSC 4012: Neutralization & Indicators Practice: Ex. 6.15, p. 6.35 Ex. 6.16, p. 6.35

10. PSC 4012: Neutralization & Indicators pH  Property that distinguishes acidic, basic and neutral solutions  Measures the concentration of H + ions in solution  Can be determined by indicator, pH paper, pH meter, etc.  pH scale: 0 – 14  pH < 7 (Acidic solution: Acids)  pH = 7 (Neutral solution: Salts)  pH > 7 (Basic solution: Bases)

11. PSC 4012: Neutralization & Indicators Indicators: What is an indicator?!

12. PSC 4012: Neutralization & Indicators Indicators:

13. PSC 4012: Neutralization & Indicators Indicators: What is an indicator?! Substance whose colour changes according to the level of pH of the solution that it is added to

14. PSC 4012: Neutralization & Indicators Indicators:

15. PSC 4012: Neutralization & Indicators Indicators: The change of colour occurs in a range of pH (turning point) that is particular for every indicator. Fig 5.8, p. 5.47 Fig 5.9, p. 5.48

16. PSC 4012: Neutralization & Indicators Practice: Ex. 5.34 & 5.35 p. 5.49