Neutralization Reactions

Type of acid-base reaction

Strong Acid + Strong Base----all OH- ions combine with H+ ions to give
water molecules

Produce water and a SALT, MX. A salt is an ionic compound.
HX + MOH  MX + H2O
ACID + BASE  SALT + WATER
Example 1:
NaOH(aq) + HCl(aq)  NaCl(aq) + H2O(l)
 What are the spectator ions?
 What is the net ionic equation?
Example 1: continued
NaOH(aq) + HCl(aq)  NaCl(aq) + H2O(l)
Na+(aq)+ OH-(aq) + H+(aq)+ Cl-(aq)  Na+(aq)+ Cl-(aq)+
H2O(l)
 What are the spectator ions?
Na+ and Cl What is the net ionic equation?
OH-(aq) + H+(aq)  H2O(liq)----always with
strong acids and bases
Salts
 Ionic compounds
 Formed using cation from base and anion of acid
 Can have acidic or basic properties if one acid/base
component is strong and the other is weak.
 Examples: NaCl, Na2SO4, MgCl2
Example 2:
 Predict the products from the acid-base reaction
between H2CO3 + Sr(OH)2
 Write the complete, balanced equation as well as the
net-ionic equation.
Practice!
Complete and balance the following acid-base reactions.
Write the net-ionic equation as well:
1) HClO4 + NaOH 
2) HBr + Ba(OH)2 
3) HNO3 + KOH 
4) Ca(OH)2 + HNO3 
5) Mg(OH)2 + HCl 
What are acid-base
indicators?
 Contains a weak acid and its conjugate base
 Weak acid—one color
 Conjugate base—different color
 Changes color based on what solution (acidic or basic)
it is placed in.
 Change color over a specific pH range –transition
interval
 Used when specific pH measurements not needed, seen
a lot with titrations
Common Indicators
 Phenolphthalein
 Litmus indicator
 Broad pH range
 Litmus—
 Dye originating from lichens
 pH < 4.5 (red), pH > 8.3 (blue)
Buffers
 A mixture composed of a weak acid and its conjugate
base OR weak base and its conjugate acid
 buffers” or reduces the affect of a change in the pH
of a solution
 Absorbs slight changes in pH resulting from the addition
of small acid/base amounts to water.
 Buffer capacity—
 indicates how much strong acid/base can be tolerated in
a buffer solution before pH changes
 Trait of buffer
Types of buffers
1) Acidic Buffers
 Formed from mixing a weak acid and its conjugate base
 pH < 7
2) Basic Buffers
 Formed from mixing a weak base and its conjugate acid
 pH > 7
Why are buffers important
to us?
 Buffers present in our body keep fluids within a certain
pH range.
 Blood has a pH range of approximately 7.3-7.4.
 A buffer involving H2CO3/HCO3- maintains the blood
pH
Homework:
 Additional pH calculations worksheet