Chemistry Lesson
Acids and
Bases
Prepared by: Sylvia Fran

What are
acids and
bases
Theories to
explain them

What are acids and bases ??

Acid A compound with a sour taste.
It changes the dye color of the litmus to red

Reacts with the active metal producing hydrogen gas
Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)

Reacts with carbonate or bicarbonate salts causes
effervescence and producing carbon dioxide gas,
reacts with the bases giving salt and water.
Na2CO3(s) + H2SO4(aq)  Na2SO4(aq) + H2O(l) + CO2(g)

a compound with a bitter taste and slippery feel.
It changes the dye color of the litmus to the blue
color.
Base

What are
acids and
bases
Theories to
explain
them

Theories to
explain them
one
Arrhenius
Two
Bronsted-Lowry
Three
Lewis

Arrhenius
Acid
the substance
that ionizes or
dissociates in
water and
gives one or
more
hydrogen ions
H+
Base
the substance
that ionizes or
dissociates in
water and
gives one or
more hydroxide
ions OH-

Example
Acid
Base

Neutralization Reaction

›Carbon dioxide and other
compounds give acidic solutions
in water, however they do not
contain ion H+ in their structure
Observations on Arrhenius’s Theory

Ammonia and some
other compounds give
alkaline solutions in
spite that it does not
contain the hydroxide
ion in its structure
Observations on Arrhenius’s Theory

Bronsted-Lowry
Acid
the substance that gives
up the proton H+ ( proton
donor).
Base
the substance that has
the ability to accept the
proton ( proton acceptor).

Neutralization Reaction

Lewis
›Lewis acid
is a substance
that accepts an
electron pair or
more ›
Lewis base
is a substance that
donates an
electron pair or
more

Lewis Acid
Lewis Base