Acids, Bases, and Salts

1
Acids, Bases, and Salts

• Chapter 23

2
Acids and Bases Section 1

• What do you think of when you hear acid?
• Acids have at least 1 hydrogen atom that can be
  removed
• Acid produces H in a water solution.
• H reacts w/ H2O to form H3O ? hydronium ion

3
Properties of Acids

• Taste sour
• Burns on skin
• Corrosive irreparable damage
• React strongly w/ certain metals and produce H2
  gas
• React w/ indicators to produce different colors
• Indicator organic compound that changes color in
  an acid or base.

4
Common Acids
5
Bases

• Ex baking powder, Mallox and antacids are bases
• Soaps clean greasy, fatty substances (bases)
• Base produce hydroxide ion,OH-, in H2O solution.
  Also, accepts H ion.

6
Properties of Bases

• Opposites of acids
• Many are crystalline solids
• Most are ionic compounds
• Feel slippery and have bitter taste
• Corrosive and cause severe burns
• React w/ indicators to produce different colors

7
Common Bases
8
Strengths of Acids and Bases

• Section 2

9
Strong and Weak Acids

• Strength depend on how many particles dissociate
  into ions
• Strong Acid nearly all molecules dissociate into
  ions
• Ex HCl, HNO3, H2SO4

10
Strong and Weak Acids

• Weak Acids only small amount dissolves in water
• Ions do the damage more ions more damage!!
• Ex Acetic Acid and Carbonic Acid

11
Strong and Weak Acids
12
Strong vs. Weak

• Strong ?
• All Products
• Weak ?
• Some Reactants and Some Products

13
Strong and Weak Bases

• Most bases are ionic compounds
• Strong Base dissociate completely to its ions.
  Ex sodium hydroxide, NaOH
• Weak Base does NOT dissociate completely. Ex
  ammonia, NH3

14
Dilute and Concentration

• Dilute more water than acid
• Concentrated more acid than water
• Can have concentrated weak acid and dilute strong
  acid

15
Measuring Strength

• pH measure of concentration of H
• More H the lower the pH
• Scale from 0 14
• 7 neutral, concentration of OH- concentration
  of H
• Below 7 acidic, more H
• Above 7 basic, more OH-

16
pH Scale
17
Buffers

• Def solutions containing ions that react with
  additional acids or bases to minimize effects on
  pH

18
Salts

• Section 3

19
Neutralization

• Def rxn between an acid and a base that takes
  place in a water solution.
• 2 rxns occur HCl(aq) NaOH(aq)
• H3O(aq) OH-(aq) ? H2O(l) water
• Na(aq) Cl-(aq) ? NaCl(aq) salt

20
Salt Formation

• Salt compound formed when (-) ion from acid
  combines with () ion from base
• Ex NaCl

21
Acid Base Rxns

• acid base ? salt water
• 2HCl(aq) Ca(OH)2(aq) ? CaCl2(aq) 2H2O(l)

22
Soaps and Detergents

• Polar(water) and Nonpolar(grease fat) substances
• Like dissolves Like
• Polar dissolves Polar, etc.
• Soaps have both Polar and Nonpolar ends
• Mix with water and grease
• Hydrocarbon Chain is 12 - 18 carbons

23
(No Transcript)
24
Soap Scum

• Salts form that are insoluble in water
• Detergents do NOT make insoluble salts
• can be used in cold water