Acids and Bases
Properties of Acids
 What is an Acid?
 An acid is any substance that creates
Hydrogen Ions (H+) in water.
 Acids share several characteristics…
1.
2.
3.
4.
Acids taste sour
Acids react with metals
Acids react with carbonates
Acids turn blue litmus red
Properties of Acids
 Sour Taste
Items such as citrus
fruits are acidic in
nature
They contain citric acid
which gives them their
sour taste
Properties of Acids
Acids react with metals
Acids will “eat away” at metals such as
magnesium zinc, and iron.
This property is described as being corrosive
Acids react with carbonates
Carbonate ions (CO32-) have a negative charge
and when acids react with them Carbon Dioxide
gas is produced
An example would be the reaction of Hydrochloric
Acid (HCl) with Limestone
Uses of Acids
Acids are used in a variety of ways every
day:
Many of the foods we eat contain acids
Acids are often used in cleaning supplies
Acids in your stomach allow you to digest food
Lactic acid in your muscles causes fatigue
Acids are used in lawn care products
Examples of Acids
Hydrochloric Acid – HCl
Nitric Acid – HNO3
Sulfuric Acid – H2SO4
What do you notice about the first letter of
each?
What does this tell you about the
molecule?
Properties of Bases
 What is a base?
 A base is any substance that produces
Hydroxide Ions ( OH-) in water
 Bases share several characteristics:
1.
2.
3.
4.
Bases have a bitter taste
Bases feel slippery
Bases turn red litmus blue
Bases do not react with metals or carbonates
Properties of Bases
 Bases have a bitter
taste
Tonic water is a drink
that has a bitter taste
due to the base quinine.
Properties of Bases
 Bases have a slippery
feel
Items such as soap and
shampoo are bases
Uses of Bases
Bases are also useful to us everyday:
Baking soda reacts with acids in baking to
create the carbon dioxide gas that causes
bread to rise
Milk of Magnesia and Calcium Carbonate are
used to neutralize stomach acids
Many cleaning supplies have bases in them
Bases are used to help make mortar and
cement
Examples of Bases
 Sodium Hydroxide – NaOH
 Potassium Hydroxide – KOH
 Calcium Hydroxide – Ca(OH)2
 Magnesium Hydroxide -- Mg(OH)2
 What do you notice about the ending of each
base?
 What does this tell you about each molecule?
Measuring the Strength of Acids and
Bases
To measure the strength of Acids and
Bases we use the pH scale which ranges
from 0 – 14.
The pH scale measure the concentration of
Hydrogen Ions in a solution
When pH is low, the concentration of hydrogen
ions is high.
The lower the pH the stronger the Acid
The higher the pH the stronger the base
A pH of 7 is considered neutral
The pH scale…
What happens when Acids and bases
React with each other?
 The reaction between an acid and a base is
called a neutralization reaction
The products of these reactions are a salt and water
 A salt is any ionic compound formed by a neutralization
reaction
 Water comes from the combination of the hydrogen ions
and the hydroxide ions
Although it is called a neutralization reaction, the
resulting solution is not always neutral (pH of 7). It
depends on the strength of the acid and the base that
are combined.