Acids and Bases
Chapter 23
Common Acids and
Name
Formula
Strong/Weak
Where is it
found?
Hydrochloric acid
HCl
Strong
The stomach, in
the lab.
Sulphuric acid
H2SO4
Strong
Acid rain, car
batteries, the
lab.
Nitric acid
HNO3
Strong
Acid rain, in the
lab.
Ethanoic (acetic)
acid
CH3COOH
Weak
Vinegar
Methanoic (formic)
acid
HCOOH
Weak
Ant & nettle
stings,
descalers
Citric Acid
C6H8O7
Weak
Citrus fruits
Acids
• Acids are H+ or
proton donors:
• Properties
• Acids taste sour (e.g.
vinegar, lemon juice).
• Acids are harmful to
living cells.
• Aqueous solutions of
all acids contain
hydrogen ions, H+.
Water is needed
Common Bases
Name
Formula
Where is it found?
Sodium hydroxide (caustic soda) NaOH
Oven cleaners, in the
lab.
Calcium hydroxide
Ca(OH)2
Soil lime, limewater
Magnesium oxide (magnesia)
MgO
Indigestion tablets
Calcium carbonate
CaCO3
Limestone, soil lime
Sodium hydrogencarbonate
(bicarbonate)
NaHCO3
Baking powder
Ammonia
NH3
Cleaning fluids, in
the lab.
Base properties
• Most bases are
oxides, hydroxides or
carbonates of metals
• Soluble bases are
known as alkalis.
• Aqueous solutions of
alkalis contain
hydroxide ions, OH-.
• Bases taste bitter. .
• Bases feel slippery
Base and indicators
• Bases turn red litmus
blue. A common indicator,
used to detect the presence of
a base, is phenolphthalein
which, when mixed with a
base, turns pink.
• Bases release hydroxide
ions in water solutions.
• NaOH (s) + H2O (l) à Na1+
(aq) + OH1- (aq)
• NH4OH (aq) ß -> NH41+
(aq) + OH1- (aq)
pH scale
• Water is defined as having a pH value of
7- neutral.
• Acidic solutions have pH values below 7.
• Alkaline (basic) solutions have pH values
above 7.
• pH is a measure of the number of
hydronium or hydroxide ions
• Logrithimic scale
pH scale
Reactions of Acids
With metals
•
Metals above copper in the
reactivity series will react with
acids, giving off hydrogen gas.
The metal dissolves, forming a
salt.
• METAL + ACID  SALT +
HYDROGEN
• ex. Mg(s) + H2SO4(aq) 
MgSO4(aq) + H2(g)
• This is why acids corrode
metals, and must be stored in
glass containers.
Base reactions
• With bases (metal oxides
and hydroxides)
• The base dissolves in
the acid and neutralises
it. A salt is formed.
• ACID + BASE  SALT +
WATER
• ex.
H2SO4(aq) +
CuO(s)  CuSO4(aq) +
H2O(l)
• With metal carbonates
• Metal + Base Salt +
water + CO2
• 2HCl(aq) + CaCO3(s) 
CaCl2(s) + H2O(l) +
CO2(g)
•
Indicators
• Indicators- an organic
compound that turns
color in the presence
of an acid or base
Naming Acids
– Prefix is always hydro
– Name the second element with the suffix ic
– HCl – hydrochloric
– HF- Hydrofluoric
•
For the acid containing the most common polyatomic
ion of its group simply use the first part of the
polyatomic name and follow with the suffix ic.
For the acid containing the polyatomic with one less
oxygen than the ic, use the suffix ous.
For the acid containing the polyatomic with two less
oxygens than the ic, use the prefix hypo and the
suffix ous.
For an acid containing the polyatomic with one more
oxygen than the ic, use the prefix per and the suffix ic.
Naming Bases and Salts
• Follow regular naming rules
Acid Reactions
ACID
+
BASE

SALT
+
WATER
Hydrochlor
ic Acid
+
Sodium
Hydroxide

Sodium
Chloride
+
Water
HCl
+
NaOH

NaCl
+
H2O
ACID
+
METAL

SALT
+
HYDROGEN
GAS
Hydrochloric
Acid
+
Magnesium

Magnesium
Chloride
+
Hydrogen
HCl
+
Mg

MgCl2
+
H2
ACID
+
CARBONATE
SALT
+
WATER
+
CARBO
N
DIOXID
E GAS
Hydrochloric
Acid
+
Calcium
Carbonate
Calcium
Chloride
+
Water
+
Carbon
Dioxide
Molarity
• Molarity indicates the concentration
• Given in the unit Moles/Liters
• Moles is the SI unit for quantity- it indicates
6.022 x1022 atoms or molecules of a substance
• It is equal to the atomic weight of the element in
grams
• Ex. 16.00 g of O is one mole
• 32.00 g of O2 one mole
Neutralization
• Reactions in which an acid is added to a
base cause neutralization
• This usually results in a salt and water
• IN the case of carbonate bases it results in
a carbonate salt, water, and carbon
dioxide
Titration
• A titration is a process where by the
concentration of an unknown acid or base
is determined by using a solution with a
known concentration.
• This solution is known as the standard
solution.
• The formula M1V1=M2V2 is used to
determine the molarity of the unknown