Download Acid and Base PPT

Acids & Bases
They are everywhere..
In your food
In your house
EVEN IN YOU!!!!!
https://www.youtube.com/watch?v=mnbS56HQbaU
https://www.youtube.com/watch?v=i2x4foEuRcI
Intro Video up to 1:10
OBJECTIVES
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What is an Acid?
Properties of an Acid
Strong Acid
Weak Acid
Uses of Acid
What is a Base
Difference between Bases and Alkali
Alkali
Properties of Alkali
Properties of Bases
Uses of Bases
What is an Indicator?
Where do we find Acids and Bases?
 They are compounds...
that are fundamental to the functioning of
our world. – we need them!
 They are essential to Life;
 They are responsible for many, many
processes in nature;
 They are important in many products and
processes we have come to expect in our
daily lives.
Continue Video to 3:15
What is an acid?
 An acid is a solution that has an
excess of Hydrogen (H+ ions).
 The more H+ ions, the more
acidic the solution.
Properties of an Acid
 Tastes Sour
 Conducts Electricity
 Corrosive; (they break
down certain substances.
Many acids can corrode
fabric, skin,and paper).
 Some acids react
strongly with metals.
 Turns blue litmus
paper red
Chemical Properties of Acid
 Acids react with bases to form a salt and
water only
 Ex. Sulphuric acid reacts with copper (II)
oxide to form a salt called copper (II) sulphate
and water.
 This reaction is called neutralisation.
A Strong Acid
A Weak Acid
Some Common Acids
Uses of Acids
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Acetic Acid = Vinegar
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Citric Acid = lemons, limes, &
oranges. It is in many sour
candies such as lemonhead &
sour patch.
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Hydrochloric acid is used in
industry to remove rust from
metal before they are painte.
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Ascorbic acid = Vitamin C
which your body needs to
function.
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Sulfuric acid is used in the
production of fertilizers, steel,
paints, and plastics. Also in Car
batteries.
Checkpoint
 What ions do acids produce in water?
 State three properties of acids
 Explain what is meant by a strong acid. Give
one example.
 Explain what is meant by a weak acid. Give
one example.
 Some dry citric acid crystals are placed on a
dry piece of litmus paper. Will there be a
colour change? Explain your answer
What is a base?
 A base is a solution that has
an excess of OH- ions.
 Another word for base is
alkali.
 Bases are substances
that can accept
hydrogen ions
 H + OH = ________
Bases
Alkalis
Difference between Bases and Alkali
Chemical Properties of Alkali
Chemical Properties of Alkali
Properties of a Base
 Feel Slippery
 Taste Bitter
 Corrosive
 Can conduct electricity.
(Think alkaline batteries.)
 Do not react with metals.
 Turns red litmus
paper blue.
Uses of Bases
 Bases give soaps,
ammonia, and many other
cleaning products
 The OH- ions interact
strongly with certain
substances, such as dirt
and grease.
 Chalk and oven cleaner are
examples of familiar
products that contain
bases.
 Your blood is a basic
solution.
Video to 12:37 pH scale
Uses of Bases
 Sodium hydroxide and potassium hydroxide
are used in soap making
 Ammonia solution is used in window cleaners
 Magnesium hydroxide is used I toothpastes to
neutralise the acid produced by bacteria
 Calcium hydroxide (slaked lime) is used to
neutralise acids found in acidic soil
Some Common Alkali
Checkpoint
What is a base? Give 3 examples.
Define what is an alkali. Give 3 examples
State three properties of alkalis
Explain why iron (II)hydroxide is a base, but
not an alkali.
 Write a balance chemical equation for the
following reactions:
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 A. potassium hydroxide + ammonium chloride
 B. Calcium hydroxide + ammonium chloride
Indicators
Video to 12:37
Indicators
pH Scale
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pH is a measure of how acidic or basic a
solution is.
• The pH scale ranges from 0 to 14.
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Acidic solutions have pH values below 7
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A solution with a pH of 0 is very acidic.
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A solution with a pH of 7 is neutral.
• Pure water has a pH of 7.
• Basic solutions have pH values above 7.
pH Scale
• A change of 1 pH unit represents a
tenfold change in the acidity of the
solution. (X 10)
• For example, if one solution has a pH of 1
and a second solution has a pH of 2, the
first solution is not twice as acidic as the
second—it is ten times more acidic.
Universal Indicator
Types of Oxides
Types of Oxides
Acid – Base Reactions
 A reaction between an
acid and a base is
called neutralization.
An acid-base mixture
is not as acidic or
basic as the individual
starting solutions.
Acid – Base reactions
 Each salt listed in this
table can be formed by
the reaction between an
acid and a base.
Checkpoint
 Name three common indicators and their colour
change in strong acidic and strong alkaline
solutions.
 What is mean by the pH of a solution?
 What are the four types of oxides? Give an
example of each
 What colours would you expect to see when the
follwoign indicators are added to a solution of pH
5?:
 a. litmus
b. phenolphthalein c. methyl orange
Salts
Examples of Salts
Uses of Salts
Soluble and Insoluble Salts
Acids and Bases in Nature
@ 15:20
Acids and Bases are constantly at work
interacting with each other; otherwise all
our water would be acidic….No? Explain…
After viewing the final episode, answer these
Qs:
1. How does pH affect plant growth and
gardeners gardens?
2. How does pH affect farmers’ crops?
3. What is the cause of acid rain?
4. How does acid rain affect living and nonliving things?