Download Acids and Bases

Acids and Bases
Dissociation
• In water all ionic compounds
dissociate into its ionic parts
• So NaCl in water dissociates into Na+
and Cl• So H3PO4 dissociates into 3H+ and
PO4-3
• Remembers ionic compounds are
formed by metals and nonmetals or by
metals and polyatomic ions
Identifying an Acid
• An acid is any compound that
+
forms an H3O (called
hydronium) ion in water
• Usually acids have an H in front
of the compound
• In general they have a sour taste
and react with most metals
Naming Acids
• Look at the acid’s chemical formula, try to name it
as if it where an ionic compound
• Then eliminate the 1st word
• If no “O” is in anion then add hydro to the beginning
and trade the –ide for –ic
• If the anion has “O” then trade –ate or –ic if the
anion ended in –ate originally
• If anion has “O” then trade –ite or –ous if the anion
ended in –ite originally
• Finally add the word “acid” to the end-
Name these acids
•
•
•
•
•
•
HBr
H3N
H2SO4
HI
HNO3
HNO2
Common Acids
Name
Formula
Use
Acetic Acid
CH3COOH Vinegar
Carbonic Acid
H2CO3
Carbonated Drinks
Hydrochloric Acid HCl
Digestive juices in stomach
Nitric Acid
HNO3
Fertilizer
Phosphoric Acid
H3PO4
Fertilizer
Sulfuric Acid
H2SO4
Car Battery
Identifying a Base
• A base is any compound that
forms an OH ion (called
hydroxide) in water
• Usually bases have an OH at
the end of the compound
• Bases usually have a bitter taste
and a slippery feel
Common Bases
Name
Formula
Use
Aluminum
hydroxide
Al(OH)3
Deodorant, antacid (tums)
Calcium hydroxide Ca(OH)2 Concrete, plaster
Magnesium
hydroxide
Mg(OH)2 Antacid, laxative
Sodium hydroxide
NaOH
Drain cleaner, soap
production
Neutralization
• When an acid and base react it is
called a neutralization reaction
• During this reaction a salt and
water is always formed
• Common salts include but are not
limited to:
• NaCl, Na2CO3, KCl, KI, MgCl2,
CaCO3, and NH4NO3
Proton Donors and Acceptors
• Acids are generally defined as
proton donors (meaning they give
away the H+)
• Bases are generally defined as
proton acceptors
• These alternate definitions of acids
and bases help us when compounds
react with water or are insoluble
Acid Strength
• Acids and bases are rated on a pH scale
• Where 1 is the strongest acid and 14 is the
strongest base
• 7 is neutral (water is the only neutral
compound)
• 1-4 (stronger acid)
• 4-7 (weak acid)
• 7-10 (weak base)
• 10-14 (strong base)
Acid Strength (ctd.)
• Between any 7 and 6 an acid gets 10
times stronger, between 7 and 5 an acid
gets 100 times stronger the scale it
logarithmic
• Strength is defined as how easily the H+
or the OH- comes off the acid or base, the
easier it comes off the stronger the acid or
base
• Strength is COMPLETELY different than
concentration
Concentration vs Strength
• Concentration refers to how diluted an
acid or base is
• Concentration DOES NOT change
the pH of an acid or base
• Hence the pH of 16M HCl is equal to
the pH of .001M HCl though there
concentrations are extremely different