1 ACIDS + BASES

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3 ACIDS Properties: (other than tasting sour and being corrosive) 1) React with metals 2) React with carbonates 3) Conduct electricity 4) Turn blue litmus paper red 5) Neutralize bases ACIDS ARE CORROSIVE

4 1) ACIDS REACT WITH METALSIf you swallowed a penny, what would happen? (DON’T TRY THIS AT HOME!!!) penny hydrochloric acid penny HCl penny acid

5 1) ACIDS REACT WITH METALS2HCl(aq) + Zn(s)  H2(g) + ZnCl2(aq)

6 2) ACIDS REACT WITH CARBONATESWhat happens when you put baking soda (sodium bicarbonate) into vinegar? HC2H3O2(aq) + NaHCO3(aq)  CO2(g) + H2O(l) + NaC2H3O2(aq)

7 3) ACIDS CONDUCT ELECTRICITYAcids are made of ions, so in water these ions separate and can conduct electricity Hydrogen ion is what makes an acid acidic HCl(aq)  H+(aq) + Cl-(aq)

8 IONIZATION IN WATER H+ Cl- H+ Cl- H+ Cl- Strong acids ionize completely in water, while weak acids only ionize slightly

9 NEGATIVELY-CHARGED ELECTRODE POSITIVELY-CHARGED ELECTRODEIONIZATION IN WATER - + H+ H+ NEGATIVELY-CHARGED ELECTRODE Cl- POSITIVELY-CHARGED ELECTRODE Cl- H+ Cl- Cl- H+

10 4) ACIDS TURN BLUE LITMUS PAPER REDBlue litmus paper is an indicator and turns red when it touches acid

11 5) ACIDS NEUTRALIZE BASESAcids can neutralize bases, so adding an acid to a base can neutralize their caustic nature HCl(aq) + NaOH(aq)  H2O(l) + NaCl(aq) Hydrochloric acid + sodium hydroxide  water + salt (sodium chloride) Corrosive + caustic  non-corrosive + non-corrosive

12 BASES Properties: (other than tasting bitter, feeling slippery) 1) Conduct electricity 2) Turn red litmus paper blue 3) Turns phenolphthalein pink 4) Neutralize acids BASES ARE CAUSTIC

13 1) BASES CONDUCT ELECTRICITYBases are made of ions, so in water these ions separate and can conduct electricity hydroxide ion makes bases basic NaOH(aq)  Na+(aq) + OH-(aq)

14 2) BASES TURN RED LITMUS PAPER BLUERed litmus paper is an indicator and turns blue when it touches base

15 3) BASES TURN PHENOLPHTALEIN PINKPhenolphtalein is colourless, and turns pink in bases (above pH 8.2) while remaining colourless in acids.

16 4) BASES NEUTRALIZE ACIDSBases can neutralize acids, so adding a base to an acid can eliminate their corrosiveness Example: Antacids to neutralize stomach acid 2HCl(aq) + CaCO3(aq)  CaCl2(aq) + H2CO3(aq) H2CO3(aq)  H2O(l) + CO2(g)

17 HOW TO MAKE ACIDS + BASESACIDS: 1) Non-metal + oxygen  non-metal oxide 2) Non-metal oxide + water  ACID! EXAMPLE: N2 + 2O2  2NO2 NO2 + H2O  HNO3 BASES: 1) Metal + oxygen  Metal oxide 2) Metal oxide + water  BASE! EXAMPLE: 2Mg + O2  2MgO MgO + H2O  Mg(OH)2

18 ACID-BASE INDICATORS Indicators change color depending on whether a substance is acidic or basic

19 Different indicators change colour at specific pH rangesACID-BASE INDICATORS Different indicators change colour at specific pH ranges

20 The strength of an acid or base is measured with pHpower hydrogen pH = power of hydrogen

21 pH = -log [H+] pH Logarithm with base 10Calculating pH pH = -log [H+] Logarithm with base 10 Concentration of hydrogen ions

22 At 25°C: From 0 to 14, with 7 being NEUTRALpH Scale At 25°C: From 0 to 14, with 7 being NEUTRAL pH < 7  acidic pH = 7  neutral pH > 7  basic

23 pH Scale

24 pH Scale Every pH level is 10x more concentrated than the level above.i.e. pH 4 is 10x more concentrated than pH 5 pH 3 is 100x more concentrated than pH 5

25 Recall: Polyatomic ions have modified names in acidsACID NAMING Recall: Polyatomic ions have modified names in acids Polyatomic ion name Acid anion name Example sulfate sulfuric H2SO4 sulfuric acid chlorate chloric HClO3 chloric acid carbonate carbonic H2CO3 carbonic acid phosphate phosphoric H3PO4 phosphoric acid

26 Recall: Most acids have hydrogenACID NAMING Recall: Most acids have hydrogen 1) Naming: HCl(aq) H2SO4(aq) Sulfuric acid Hydrochloric acid OXYACID BINARY ACID

27 H BrO3 = HBrO3(aq) bromic acid ACID NAMING2) Writing the chemical formula: bromic acid 1 + 1 - H BrO3 = HBrO3(aq)

28 ACID NAMING Oxyacids with polyatomic ions that end in “ite” are given the ending “ous” Polyatomic ion name Acid anion name Example sulfite sulfurous H2SO3 sulfurous acid chlorite chlorous HClO2 chlorous acid carbonite carbonous H2CO2 carbonous acid phosphite phosphorous H3PO3 phosphorous acid

29 ACID NAMING 1) Naming: HNO2(aq) nitrite = nitrous acid

30 H BrO2 = HBrO2(aq) bromous acid ACID NAMING2) Writing the chemical formula: bromous acid 1 + 1 - H BrO2 = HBrO2(aq)

31 HOMEWORK Page 228 # 1, 3 – 8