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Acid-Base Reactions. Strong and Weak Acids Titration Common Acid Names. Textbook section 4.3. What is an ACID?. Defined: ACID Produces H + ions in water solution BASE Produces OH - ions in water solution. Acid Characteristics: Sour Taste (lemon)
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Acid-Base Reactions • Strong and Weak Acids • Titration • Common Acid Names Textbook section 4.3
What is an ACID? • Defined: • ACID Produces H+ ions in water solution • BASE Produces OH- ions in water solution • Acid Characteristics: • Sour Taste (lemon) • Change Indicators Colors (litmus blue to red)
Strong Acids • Strong Acids Ionize completely. HCl (aq) H+ (aq) + Cl-(aq) • The strong ACIDS are: • HCl • HBr • HI • HNO3 • H2SO4 • HClO4 What are the names of these acids? Check the partner of the “H” for a hint. These must be memorized.
Weak Acids • Weak acids ionize partially. General formula: HB H+ + B- Double arrow means reversible or it does not go to completion. The equilibrium includes both products AND reactants. Compare # of HCl ions in solution to HF ions in solution. Each w/ 1.0 M concentration.
Strong Bases • Strong Bases Ionize Completely • NaOH Na+ + OH- • Hydroxides are commonly strong bases. Including: LiOH KOH Ca(OH)2 Sr(OH)2 Ba(OH)2
Weak Bases Produce OH- ions by reacting with the water. NH3 aq+ H2O aq NH4+ aq + OH- aq Pulling an H+, and leaving OH- behind. We often write water HOH, to easily keep track of this water reaction Include: ammonia NH3 amides R-NH2 Weak bases are weak electrolytes. The bulb will light up but it will be dim
Acid-Base Reactions 3 TYPES: • 1 Strong ACID - Strong BASE • 2 Weak ACID – Strong BASE • 3 Strong ACID – Weak BASE • Mix and acid and base what happens? • The results depend upon the strength of the reactants.
Strong ACID + Strong BASE • Neutralization Reaction occurs • The products are water, and an aqueous salt. (ions) Consider Nitric Acid and Sodium Hydroxide H+ + NO3- + Na+ + OH- Since they are “strong”, they fully ionize Neutralization produces Water and a salt. • Animation of Nitric acid and Sodium Hydroxide
Weak Acid – Strong Base • 2 step reaction occurs, The acid HF partially dissociates to H+ + F- Then the Base NaOH, which has dissociated to produce OH- ions (plus the Na+ ions) The H+ and OH- combine to from water • Write the complete equation for this reaction • Identify any spectator ions and then write a net ionic equation.
Strong ACID – Weak BASE The weak base gets “protonated” The strong acid is already dissociated into H+ and B-. Consider ammonia and Hydrochloric Acid NH3 + H+ + Cl- NH4+ + Cl- Methylamine and Nitric Acid CH3NH2 + H+ CH3NH3+
Poem That Makes Sense After Studying Predicting Reactions:Johnny finding life a bore, drank some H2SO4.Johnny's father, an M.D., gave him CaCO3.Johnny's neutralized, it'strue,But now he's full of CO2.
Acid Base Titration An standardizedacid (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 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 M1V1=M2V2 In this case the formula could be written MOH- VOH- = MH+VH+
Acid Definitions: Arrhenius Bronsted-Lowry Arrhenius: Acids put H+ into water Bases put OH- into water Bronsted-Lowry Acids: “ADP” Acids donate protons Bases accept protons