Reactions in Aqueous Solution:

1

• Reactions in Aqueous Solution
• Acids (section 4.3)

2
Build the following molecules using the plastic
molecular models

• Nitric Acid
• Perchloric Acid
• Hydrochloric Acid
• 3 or 4 water molecules

3
Find meanings for these

• Amphoteric
• Bronsted-Lowry
• Aqueous
• Conjugate
• Hydronium

4
What is an ACID?

• Acid Characteristics
• Taste
• Indicator

5
Acid Definitions Bronsted-Lowry

• Arrhenius
• Acids put H into water Bases put OH- into
  water
• Bronsted-Lowry Acids
• ADP
• Acids donate protons Bases accept protons
• The Bronsted-Lowry definition is broader (more
  inclusive) than the Arrhenius definition.

6
Strong Acids
Give formula and name of the 6 strong acids.

• Strong Acids Ionize completely in water. (100)
• HCl (aq) ? H (aq) Cl- (aq)
• The strong ACIDS are
• HCl
• HBr
• HI
• HNO3
• H2SO4
• HClO4

7
Weak Acids

• Weak acids ionize partially in water.
• Less than 10, usually much less than 1
  ionization.
• General formula
• Double arrow means reversible or it does not go
  to completion.
• The equilibrium includes both products AND
  reactants.

8
Strong Bases

• Strong Bases Ionize Completely in water. (100)
• NaOH ? Na OH-
• Always soluble hydroxides and Ca, Ba, Sr
  hydroxides are strong bases.
• Including
• LiOH
• KOH
• Ca(OH)2
• Sr(OH)2
• Ba(OH)2

9
Weak Bases

• Produce OH- ions by reacting with the water.
• Less than 100 ionized.
• NH3 aq H2O aq ? ? NH4 aq OH- aq
• Include
• ammonia NH3
• amides R-NH2

10
Acid-Base Reactions

• 3 TYPES
• 1 Strong ACID - Strong BASE
• 2 Weak ACID Strong BASE
• 3 Strong ACID Weak BASE

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Strong ACID Strong BASE

• Neutralization Reaction
• The products are water, and an aqueous salt.
  (ions)

12
Weak Acid Strong Base

• Weak acid only partially ionized.
• Strong base fully ionized.
• The H and OH- combine to form water.
• All H gets used up (reacted).
• The anion (salt of the weak acid is not used up
  or reacted).

13
Strong ACID Weak BASE

• The weak base gets protonated (H added to the
  base)
• Ammonia and Hydrochloric Acid
• NH3 H Cl- ? NH4 Cl-
• Cross out the spectators
• Methylamine and Nitric Acid
• CH3NH2 H NO3- ? CH3NH3 NO3-
• Cross out the spectators

14

• Johnny finding life a bore, drank some
  H2SO4. Johnny's father, an M.D., gave him
  CaCO3. Johnny's neutralized, it's true, But now
  he's full of CO2.

15
Find meanings for these

• Amphoteric
• Bronsted-Lowry
• Aqueous
• Conjugate
• Hydronium

16
Acid Base Titration

• An standardized acid (known concentration) may be
  used to determine the
• unknown strength of a base. (or visa-versa)
• Using an indicator (solution that changes color)
• you can know when the added solution is exactly
  equal to the unknown.
• this is known as the EQUILVALENCE POINT.

17
Acid-Base titration

• Objective Determine the equivalence point.
• Equivalence point nOH- nH
• If 25.00mL of 0.0800M NaOH is needed to react
  with 10.00 mL of HCl. What is the molarity of
  HCl?
• Write the reaction
• Use M1V1M2V2
• In this case the formula could be written MOH-
  VOH- MHVH