2. Acids & Bases

3. Properties of Acids and Bases Acids react with bases Acids are electrolytes Acids act on some metals to produce H 2(g) Acids turn litmus paper RED Acids taste SOUR. Bases react with acids Bases are electrolytes Bases feel slippery Bases turn litmus paper BLUE Bases taste BITTER.

5. Litmus is: RELUE ACIASE

6. The pH scale is a number scale for measuring how acidic or basic a solution is. One simple definition of acids is that they are chemical compounds that produce a solution with a pH of less than 7 when they dissolve in water. Bases are compounds that produce a solution of pH of more than 7 when they dissolve in water. If a solution has a pH of 7, it is said to be neutral (neither acidic nor basic). Notice that the “p” in pH is always lower case, and the “H” is always upper case. pH values do not have a unit of measurement written after the number.

7. An INDICATOR is a weak organic acid or base with different colors for its conjugate acid and base forms. Ex:HIn + H 2 O  In - + H 3 O + yellow red When the indicator is in acid, the excess H 3 O + shifts the equilibrium and the solution turns YELLOW. An indicator is in its CONJUGATE ACID form when in HIGHLY ACIDIC solutions: [HIn]>[In - ] In basic solutions, the [H 3 O + ] is very low so that the equilibrium shifts to the In- side and the solution turns RED. An indicator is in its CONJUGATE BASE form when in HIGHLY BASIC solutions:[HIn]<[In - ] ***Note: HIn is acid form of indicator. In - is the conjugate base of the indicator.

8. A UNIVERSAL INDICATOR is an indicator solution which changes color several times over a range of pH values.

9. Some Common Acids and Bases that You Should Know Sulphuric Acid: H 2 S0 4 Hydrochloric Acid: HCl Nitric Acid: HNO 3 Acetic Acid: CH 3 COOH Sodium Hydroxide: NaOH Potassium Hydroxide: KOH Ammonia: NH 3

10. Some work for you to try!! Workbook Page 84 & 85

11. Some Common Acids naming scheme: {H + something} Three Acids: 1.H + Non Metal (found on right side of Periodic table {Halogen}) a)start with “HYDRO b)add non metal c)change ending to IC most times {RIC} d)add word “acid” Example: HF = hydrofluoric acid

12. 2. H + Poly atomic ion with a ATE ending a)name P.A.I. b)change ending to “RIC” c)add word “acid” Example: H 2 SO 4 = sulphuric acid 3. H + Poly atomic ion with a ITE ending a)name P.A.I b)change ending to “rOUS” c)add word “acid” Example: HNO 2 = nitrous acid

13. Some more for you to try Work Book Pages 86 & 87

14. A word equation for an acid reacting with a base might look like: Hydrochloric acid plus Sodium hydroxide reacts to produce salt (sodium chloride) and water. A skeletal equation might look like: HCl + NaOH  NaCl + H 2 O In this case the skeletal is also a balanced equation.

15. Net Equations: Sometimes we are asked to write a net equation for the reaction: H + + OH -  H 2 O The net is the acid + base  water We often refer to reaction that involves an acid & a base as a “NEUTRALIZATION” equation, because an acid & a base have been neutralized to form water (neither acid nor base) Bases are often described as CAUSTIC if they are strong. Ex drain cleaner, oven cleaner

16. You will be expected to identify a neutralization reaction from pieces (an incomplete equation) & add the missing pieces then balance it. Ex) Complete & balance the following: A neutralization reaction with Phosphoric Acid produced Calcium Phosphate

17. Unbalanced (Skeletal): H 3 PO 4 + Ca(OH) 2  Ca 3 (PO 4 ) 2 + H 2 O Balanced: 2H 3 PO 4 + 3Ca(OH) 2  Ca 3 (PO 4 ) 2 + 6H 2 O

18. 1. Write a neutralization equation with sulphuric acid that produces Calcium sulphate. 2. What base did a student spill on themselves if they produced Aluminum acetate to help stop the reaction in their skin. Write a balanced equation to show how the product was produced.

19. Many acids will only behave as an acid when they are mixed with water. For this reason acids are often written as being dissolved in water (The word Aqueous means dissolved in water), we shorten Aqueous to aq. Example HCl is written as HCl (aq)

20. Please try the reading check From Text on: page 225 # 1 to 5 page 227 # 1 to 5 page 228 # 1 to 4 WB page 88, 91, & 92

21. BASIC ANHYDRIDE BASIC ANHYDRIDE An oxygen-containing compound that reacts with water producing a basic solution. Metal Oxides = Metal+Oxygen BASIC Metal Oxides = Metal+Oxygenwhen added to water produce BASIC solutions. Na 2 O (s)  2Na + (aq) +O 2- (aq) OH - O 2- +H 2 O  2OH - Completing the balancingOH Completing the balancing:Na 2 O (s) +H 2 O  2NaOH

22. ACIDIC ANHYDRIDE ACIDIC ANHYDRIDE-An oxygen-containing compound that reacts with water producing an acidic solution. NONMETAL OXIDES=NONMETAL + OXYGEN ACIDIC NONMETAL OXIDES=NONMETAL + OXYGEN when added to water produce ACIDIC solutions.

23. The nonmetal oxides you should know are the SO X, CO X and NO X.

24. NOX NOX from combustion reactions such as in an automobile cause some N 2 to react with O 2 in the air. N 2 + O 2  2NO2NO+O 2  2NO 2 N 2 + 2O 2  2NO 2 2NO 2 +H 2 O  HNO 2 +HNO 3 SO X from coal and oil burning S + O 2  SO 2 SO 2 +H 2 O  H 2 SO 3 2SO 2 +O 2  2SO 3 SO 3 + H 2 O  H 2 SO 4 CO X CO X from fossil fuels, etc. CO 2 + 2H 2 O  H 3 O + + HCO 3 -