A.Physical
Properties
What are physical properties?
Physical properties are the properties of a substance that can be
observed,measured,or tested by our senses, such as colour,size,form
(solid,liquid, gas) odor,taste,boiling point,melting point,solubility,pliancy,hardness,heat
and electric conductive. Table 4.1 shows the physical properties of some substances.
Now, let’s study some physical properties of substances.
TABLE
4.1 Physical properties of some substances
|
Substance
|
Chemical
Symbol
|
Substance’s
Form
|
Color
|
Melting
Point
|
Boiling
Point
|
Taste
|
Odor
|
|
Water
|
H20
|
Liquid
|
No
color
|
0
|
100
|
Tastelees
|
Odorlees
|
|
Sugar
|
C12H22O11
|
Solid
|
White
|
185
|
-
|
Sweet
|
Odorlees
|
|
Sulfur
|
S
|
Solid
|
Yellow
|
113
|
445
|
-
|
Odorlees
|
|
Table
Salt
|
NaCL
|
Solid
|
White
|
804
|
1413
|
Salty
|
Salty
smell
|
|
Mercury
|
Hg
|
Liquid
|
Silver
white
|
-37,87
|
356,58
|
-
|
-
|
B.
Chemical Properties
What do you know about
chemical properties of a subtance? Unlike thephysical charateristic , the
chemical property of a subtance is not easy to be observed. That’s because the
chemical property of of a subtance is related to the reaction of the subtance
to other subtance in producing a new subtance. The property oh the new subtance
is so different with its intial subtance. Some chemical properties are listed
in Table 4.8
Example of chemical
properties are the acidity or alkalinity (pH), reactivity with water or other
subtance , corroded,easily burnt, and poisonous for humans (toxic)
The Chemical Characteristic
of some Substance
|
Substance
|
Chemical characteristic
|
|
Iron
Carbon
Cyanide Acid
Neon
|
Corroded
Can be burnt ( reacts with
oxygen to produce carbon dioxide)
Poisonous for humans
Inert (doesn’t react with
anything)
|
MIXTURES
SEPARATION
1. The particles of a mixture
can be physically and chemically separated. The physical properties that can be
used as the basic of mixture separation are particle’s size, particle’s boiling
point, and solubility. The chemical characteristic that can be used as the
basic of mixture separation is the making of the sediment as the effect of
chemical reaction.
2. Some methods of mixture
separation are filtration, decantation, sublimation, centrifugation,
crystalisation, chromatography, evaporation, distillation, separatory funnel,
and floculation.
3. The filtration method is used
to separate a mixture wherein the shaper subtance are in the froms of liquid
(liquid substance) and solid matter (solid substance) with a quite small size
of the solid matter.
4. Decantation means carefully
pouring the liquid and leaving the unsoluble solid at the bottom of beaker
glass.
5. Centrifugation is a
separation technique for mixture with different specific grafity by spinning
the mixture with high velocity.
