CHAPTER 1

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Transcript CHAPTER 1

CHAPTER 1
CE CHEMISTRY
MATTER
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Anything that has mass and occupies space
Weight
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Mass
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Measure of the quantity of matter
Law of conservation of matter
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Measure of earth’s gravity
Matter cannot be created or destroyed
States of matter
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Solid
Liquid
Gas
PROPERTIES OF MATTER
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THE PROPERTIES OF MATTER CANNOT BE BROKEN
DOWN WITHOUT A CHEMICAL CHANGE
PHYSICAL PROPERTIES
 Such properties are color, density, boiling point ,
melting point, and hardness
PHYSICAL CHANGE- Properties never change
 Liquid turning into a gas
CHEMICAL PROPERTIES
 The way a substance reacts with another
substance
 2Na(s) + Cl2(g)  2NaCl(s)
CHEMICAL CHANGE-Properties are altered
SUBSTANCES
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PURE SUBSTANCE - Properties the same
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ELEMENT - cannot be broken down by a chemical
change. Silver, gold or aluminum
COMPOUND - two or more elements that have been
chemically bonded together. This can be broken
down chemically into the elements. Sugar, baking
soda, etc.
MIXTURES
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MIXTURE - Each substance retains their
properties
HOMOGENEOUS - all particles are in the same
phase, a uniformed mixture. Salt water or air
HETEROGENEOUS - all particles are not in the
same phase, not uniformly mixed. Sand or
wood
MIXTURES CAN BE SEPARATED BY PHYSICAL
MEANS
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Filtration, chromatography, or distillation (depends on
volatility)
SOLUTIONS
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Solutions are usually homogenous liquids
You can have solutions that are a mixture
of gas and liquid. Also you can have gas
solutions like air.
ATOMS AND MOLECULES
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MOLECULES
 Smallest particle in a compound
 Diatomic molecule has two same atoms (know
these), Hydrogen gas(H2), Nitrogen gas(N2),
Oxygen gas(O2), Fluorine gas(F2), Chlorine gas(Cl2),
Bromine liquid(Br2), Iodine solid(I2)
 Polyatomic molecules have more than two elements
in it
ATOMS
 Smallest particle in a element
 All elements are single atoms Carbon (C), Aluminum
(Al), except for the diatomic molecules
SI UNITS
Length is measured in METERS
m
 Mass is measured in KILOGRAMS
kg
 Time is measured in SECONDS
s
 Temperature is measured in KELVIN K
 Amount of substance is
measured in MOLES
mol
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CONVERSIONS
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THINGS TO REMEMBER
In the metric system, the smaller prefix unit will
always have a larger number than the prefix
unit it is equal to.
1000 m = 1km (overhead)
METER IS A SMALLER PREFIX UNIT
Kelvin is absolute zero or -273.15 oC. You can
not have a temperature lower than this so
KELVIN CAN NEVER BE A NEGATIVE NUMBER
oC + 273 = K
K - 273 = oC
ROUNDING NUMBERS OFF
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In a series of calculations carry all digits unit
the final solution, THEN ROUND
If a digit needs to be rounded
If it is less than 5, the preceding digit remains
the same
If the digits are equals or is greater than 5, the
preceding digit is increased by one.
UNCERTAINTIES IN MULTIPLICATION,
DIVISION, ADDITION, AND SUBTRACTION
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Multiplication and division
 Significant figures are the same as the least precise
(number with the smallest number of significant
figures) measurements
Addition and subtraction
 The answer will have the same number of digits
beyond the decimal point as the integer (that was
added or subtracted) with the least accurate
number (last significant number is in the highest
place holder)
SCIENTIFIC NOTATION
All chemistry uses scientific notation
 Uses the base 10
 1000 = 10 x 10x 10 =103
 0.001=1/1000=1/10 x 1/10 x 1/10=10-3
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PERCENTAGES
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Calculating percentages
 Percent =number of specific items x 100
Total items in the group
DENSITY
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Density
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Measure of the mass of a substance that occupies
one unit of volume
Density = mass =
gram
= g
Volume
Centimeters cubed
cm3