SNC2P
Acids and Bases
Acids and Bases
And neutralization reactions
Acids
• Substances that release hydrogen ions
(H+) when mixed in water
• Physical Properties:
– Sour tasting
– Wet to the touch when in solution
– Water soluble
– Good conductors of electricity, therefore
electrolytes
Acids
• Chemical Properties
– React with metals to produce hydrogen gas
– Corrosive
– Make chemical indicators change colour
– React with bases to produce a neutral
solution
Acids
• Examples:
Bases
• Substances that release hydroxide ions
(OH-) when mixed in water. Also called
alkaline
• Physical Properties:
– Bitter tasting
– Slippery to the touch when in solution
– Water soluble
– Good conductors of electricity, therefore
electrolytes
Bases
• Chemical Properties
– Corrosive
– Make chemical indicators change colour
– React with acids to produce a neutral solution
Bases
• Examples:
Chemical Indicators
• Are solutions
that change
colour in acids
and in bases
• Can be either
– natural or
– synthetic
Chemical Indicators
• Litmus paper:
– Base turns it Blue!
– Acid turns it Red!
Universal Indicator is a
mixture of chemicals that
changes colour through a
wide range of pH values
The pH scale
• A numerical scale used to show how
acidic or basic a solution is
• pH stands for “power of hydrogen”
The pH scale
• pH is a logarithmic scale which means
that every unit on the scale represents a
tenfold (10X) effect on the concentration
of the solution
The pH scale: Logarithmic
• This means that pH 3 is 10 times more acidic than
ph 4.
• If the value changes by more than one number you
must multiply
– ex. From pH 5 to pH 8 = 10 x 10 x 10
multiplied by itself 3 times)
(3 steps = 10
Naming Acids
• A binary acid forms when an H+ bonds
with a non-metal
• HF (aq), HCl (aq), HBr (aq), HI (aq), H2S
(aq), and H3P (aq) are some common
binary acids
• To name them, use the following structure:
– “hydro + ______ ic acid”
Naming Acids
• An oxyacid has a non-metal and an
oxygen component
• H3PO4, HClO3, HIO3, H2SO4, HBrO3,
H2CO3, and HNO3 are some common
oxyacids
• To name them:
– “_____________ ic acid”
Naming Bases
1. Name the metal
2. Name the polyatomic (i.e. hydroxide)
• Example
– Mg(OH)2
– magnesium hydroxide
Neutralization Reactions
• A type of double displacement reaction
• Acid + Base  Water + Salt
• A salt is an ionic compound. The pH of
the products is around 7 (neutral)
Example
hydrochloric acid + sodium hydroxide 
water + sodium chloride
Practise!!
• Try the practise
questions on your
worksheet!