1. Section 20.4 Neutralization Reactions
OBJECTIVES:
Define the products of an acid-base reaction.

2. Section 20.4 Neutralization Reactions
OBJECTIVES:
Explain how acid-base titration is used to calculate the concentration of an acid or a base.

3. Section 20.4 Neutralization Reactions
OBJECTIVES:
Explain the concept of equivalence in neutralization reactions.

4. Section 20.4 Neutralization Reactions
OBJECTIVES:
Describe the relationship between equivalence point and the end point of a titration.

5. Acid-Base Reactions Acid + Base Water + Salt
Properties related to every day:
antacids depend on neutralization
farmers adjust the soil pH
formation of cave stalactites
human body kidney stones from insoluble salts

6. Ch. 21 Notes -- Neutralization
Neutralization Reactions
When an acid and base are mixed, the _______ of the acid and the __________ of the base combine to form ___________.
The _____________ (negative ion) of the acid and the _________ (positive ion) of the base come together to form a ___________.
A salt is defined as ________________ (metal plus a nonmetal) compound that can formed by acid-base neutralization.
All neutralization reactions are simple ___________ replacement reactions.
1 Mole of H+ ions exactly neutralizes 1 Mole of OH- ions.
H+1
OH-1
water
anion
cation
salt
ionic
double
H2O
HX + M(OH)  ______ ______ MX
(“Salt”)

7. Completing Neutralization Reactions Examples:
(1) Complete the following neutralization reactions.
HCl (aq) NaOH (aq)  _________ __________
HNO3 (aq) Ca(OH)2 (aq)  __________ + ________
H2SO4 (aq) KOH (aq)  _________ __________
Practice Problems: See if you can complete these on your own.
HNO3 (aq) KOH (aq)  __________ + __________
HCl (aq) Ca(OH)2 (aq)  __________ + __________
NaCl
H2O +2 −1
Ca(NO3)2
H2O 2 2 2
K2SO4
H2O 2

8. Titration
Mixing an acid with a base to determine the ______________ is called “titration.”
An ____________ is used to determine when neutralization has occurred.
________________ Solution - the solution of known concentration
______ _________ the point of neutralization when titrating. When the [H+] ions = [OH−] ions.
_______ point is when the indicator changes color.
concentration
indicator
Standard
Equivalence Point
End
Click Here to Watch Titration Video on YouTube

9. Determining the Concentration of an Acid (or Base) by Titration
(Macid)x(Vacid) = (Mbase)x(Vbase)
Practice Problems:
(1) A 25 mL solution of HNO3 is neutralized by 18 mL of 1.0 M NaOH standard solution using phenolphthalein as an indicator. What is the concentration of the HNO3 solution?
(2) How many mL of 2.0 M KOH will it take to neutralize 55 mL of a M HCl standard solution?
( ) x ( ) = ( ) x ( )
Macid
25 mL
1.0 M
18 mL
Macid = Molar
( ) x ( ) = ( ) x ( )
0.76 M
55 mL
2.0 M
Vbase
Vbase = mL

10. Titration
The concentration of acid (or base) in solution can be determined by performing a neutralization reaction
An indicator is used to show when neutralization has occurred
Often we use phenolphthalein- because it is colorless in neutral and acid; turns pink in base

11. Steps - Neutralization reaction
#1. A measured volume of acid of unknown concentration is added to a flask
#2. Several drops of indicator added
#3. A base of known concentration is slowly added, until the indicator changes color; measure the volume

12. Neutralization
The solution of known concentration is called the standard solution
added by using a buret
Continue adding until the indicator changes color
called the “end point” of the titration