Chapter 2: Antacids
Why do we need antacids?
Your body needs hydrochloric acid to
digest food.
Too much acid can cause heartburn and
ulcers and can damage your esophagus.
Antacids versus Acid Inhibitors
There are two types of medicines you can use
Antacids
Acid Inhibitors
Neutralizes the acid currently
in your system
Controls the production of
acid in your body
Work quickly but your body
can make more acid again
Long-term solution, but
needs to build up in your
system to be most effective
Alka-Seltzer ®, Rolaids ®,
Tums ®, Malox ®, Mylanta ®
Tagamat ®, Zantac ®, Pepcid
AC ®
Is it fair when a commercial compares the fast action of an
antacid to an acid inhibitor that takes up to 7 days to build up?
Section 2.1—Types of Matter
Objectives
•Define and distinguish between pure
substances and mixtures
Classification of Matter
Matter
Pure
Substances
Element
Compound
Mixtures
Homogeneous
(Solutions)
Heterogeneous
Matter
Matter is defined as anything that has
mass and takes up space.
It is classified as either a pure substance
or a mixture
Pure Substances versus Mixtures
Matter
Pure Substances
Mixtures
Every piece of
matter is exactly the
same
More than one type
of substance mixed
together
Elements versus Compounds
Pure substances are either elements or
compounds.
Elements
Compound
Every atom is the
same type of atom
More than one type
of atom chemically
bonded together.
Every molecule is
the same.
Elements
Single Atom
Element
Cannot be broken down
by chemical or physical
processes to form
anything else!
• A pure substance!
•Every atom is the same type.
•Elements can be found on the periodic table.
Compounds
Single Molecule
Made of more than one type
of atom (that is, more than 1
element) bonded together.
Compound
•A pure substance!
•Every molecule of a
compound is the same.
Can be broken down into its
elements by chemical
reactions only
Mixtures
Mixtures can be classified as homogeneous
or heterogeneous.
Homogeneous
Heterogeneous
•It looks the same
throughout
•Also called a
solution.
Different matter can
be seen (chunks,
bubbles, floaties,
layers, etc.)
Mixtures
More than 1
type of pure
substance
Mixture
•Not a pure substance!
•A physical combination – no
chemical bonds between substances
Can be separated
through physical means
– a chemical reaction is
NOT necessary.
Mixture possibilities
Mixtures can be any combination of solids,
liquids and gases:
Solid-solid: medicine tablet, alloy.
Solid-gas: smog
Solid-liquid: salt water
Liquid-liquid: lemon water, vinegar.
Gas-Liquid: carbonated water, sea water.
Gas-Gas: air
True solutions, Colloids & Suspensions
True Solution
Colloid
Suspension
Particles don’t
settle out and are
too small to
scatter light
Particles don’t
settle out but are
large enough to
scatter light
Particles will settle
out over time
Dissolved Particle Size Increases
Particles Scattering Light
If the dissolved particles are large enough
to scatter light, we say it exhibits the
“Tyndall Effect”
Solution
Light passes
through
unchanged
Colloids exhibit
the Tyndall
Effect
Light is
scattered by
larger solute
particles
Connect these concepts with Antacids
What type of matter do you think antacids
are?
Pure substance (Element or compound)
Mixture (homogeneous or heterogeneous)
Connect these concepts with Antacids
Antacids are mixtures.
They contain active & inactive ingredients
What purposes could the inactive
ingredients serve?
Connect these concepts with Antacids
Inactive ingredients might
Add enough volume to make the pill able to be
handeled
Add color
Add flavor
Allow the tablet to be compressed and formed
Let’s Practice
Example:
Determine if
each is
element,
compound,
homogeneous
or
heterogeneous
mixtures
Tin foil
Copper pipe
Concrete
Carbon tetrachloride
Sports drink
Let’s Practice
Example:
Determine if
each is
element,
compound,
homogeneous
or
heterogeneous
mixtures
Tin foil
Element
Copper pipe
Element
Concrete
Heterogeneous mix
Carbon tetrachloride
Compound
Sports drink
Homogenous mix
Physical Separation of Mixtures
 Substances in a mixture are separated by physical
processes. These are based on differences in
the physical properties of the substances.
1. Manual separation is used to separate substances
based on differences in color, shape, or size.
2. Siphoning is used to separate oil
& water. Oil & water can
be separated because of
differences in density.
Physical Separation of Mixtures
(cont.)
3. Using a magnet can
separate out metals
that are attracted to a
magnet.
4. Substances, like table salt, that are soluble in
water can be separated from other solids (for
example, sand) by simply making a solution.
Physical Separation of Mixtures
(cont.)
5. Filtration uses a screen
or filter (any porous
barrier) to separate the
differently-sized
substances in a
heterogeneous mixture.
Smaller particles (like
slat and water) will pass
through but larger ones
(like the sand) will be
trapped by a filter.
Physical Separation of Mixtures
6. The salt can then be
separated from the water
by distillation. Distillation is
a technique that separates
the components of
solutions based on
differences in their boiling
points.
Physical Separation of Mixtures
(cont.)
7. In paper
chromatography, a
mixture of substances
will separate out on
paper primarily due to
the tendency of each
to be attracted to and
travel across the
surface of another
material.
Physical Separation of Mixtures
8. Crystallization is a
separation technique for
solutions that results in the
formation of pure solid
particles from a solution
containing the dissolved
substance.
In rock candy, for example, as water evaporates from a sugar
water solution, the solution becomes more concentrated. The
amount of water present cannot keep all the sugar in the solution
dissolved. The sugar therefore crystallizes on the string.