Reactions in Aqueous Solution: Acids (section 4.3)
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Transcript of Reactions in Aqueous Solution: Acids (section 4.3)
Reactions in Aqueous Solution: Acids (section 4.3)
Build the following molecules using the plastic molecular models:
• Nitric Acid • Perchloric Acid• Hydrochloric Acid• 3 or 4 water molecules
Find meanings for these:• Amphoteric
• Bronsted-Lowry
• Aqueous
• Conjugate
• Hydronium
What is an ACID?
Acid Characteristics:
Taste:
Indicator:
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.
Strong Acids• Strong Acids Ionize completely in water. (100%)• HCl (aq) H+
(aq) + Cl- (aq)
• The strong ACIDS are:1. HCl2. HBr3. HI4. HNO3
5. H2SO4
6. HClO4
Give formula and name of the 6 strong acids.
Weak AcidsWeak 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.
Strong BasesStrong Bases Ionize Completely in water. (100%)NaOH Na+ + OH-
•Always soluble hydroxides and Ca, Ba, Sr hydroxides are strong bases. Including:LiOHKOHCa(OH)2
Sr(OH)2
Ba(OH)2
Weak BasesProduce 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
Acid-Base Reactions
3 TYPES:• 1 Strong ACID - Strong BASE• 2 Weak ACID – Strong BASE• 3 Strong ACID – Weak BASE
Strong ACID + Strong BASE
“Neutralization” ReactionThe products are water, and an aqueous salt. (ions)
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).
Strong ACID – Weak BASEThe weak base gets “protonated” (H+ added to the base)
Ammonia and Hydrochloric AcidNH3 + H+ + Cl- NH4
+ + Cl-
Cross out the spectators
Methylamine and Nitric AcidCH3NH2 + H+ + NO3
- CH3NH3
+ + NO3-
Cross out the spectators
• 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.
Find meanings for these:• Amphoteric
• Bronsted-Lowry
• Aqueous
• Conjugate
• Hydronium
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.
Acid-Base titrationObjective: 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?
1. Write the reaction2. Use M1V1=M2V2
In this case the formula could be written MOH- VOH
- = MH+VH
+