Transcript File

Matter
Pure
Substances
Elements
Compounds &
Molecules
Mixtures
Homogeneous
Heterogeneous
Solution
Matter
Matter is anything that has MASS and takes up
SPACE
Law of Conservation of Mass: Matter cannot be
created or destroyed
Matter
Examples of Matter:
• Water
• Chex Mix
• Plastic
• Humans
• Air
Examples that aren’t
Matter:
• Space
• Light
• Sound
• Energy
• Heat
Nucleus:
Middle of the atom,
made up of protons
(+ charge) and
neutrons (no charge)
The Atom: The
unbreakable building
blocks that make up all
matter
Electrons
( - charge)
Physical Properties
All matter has physical and chemical properties
Physical Properties are properties that you can
measure or see
Examples: mass, density, color, temperature,
malleability and brittleness, phase (solid, liquid,
gas)
Physical Changes
Physical changes change
the physical properties
but DO NOT change the
matter into something
else
• Phase Changes
• Changing Shape
Physical Changes
are reversible
Chemical Properties
Chemical Properties are properties that allow
the ability for a chemical change/reaction to
occur
They can only be observed when matter goes
through a chemical change, can’t know just by
looking at it
Examples: Flammability, Ability to react with
specific materials
Chemical Changes
Chemical Changes: Any
Signs of a Chemical Change
change that changes one
substance into a different
substance
Created by a chemical
reaction
Chemical changes are very
difficult or impossible to
undo
Types of Matter
Matter is separated into two major categories:
1) Pure substance cannot be separated into
different kinds of matter by physical means
and are made up of one single chemical
throughout
2) Mixtures are made up of multiple substances
Most matter in the world around us are mixtures
Matter
Pure
Substances
Elements
Compounds &
Molecules
Mixtures
Homogeneous
Heterogeneous
Solution
Elements
Element: a substance that cannot be separated
into simpler substances by chemical means
• Each element is a unique type of atom
• Atoms of the same element are all similar to
each other and different from atoms of any
other element
• Elements are located on the periodic table
Periodic Table Layout
Organized into periods (rows) and groups
(columns), elements separate from the table are
part of Periods 6 and 7
Periodic Table
Element Symbol: 1 or 2
letters that represent the
element
First letter is ALWAYS
capitalized, second letter
NEVER is
Atomic Number: Number
of Protons
Atomic Mass
The atomic mass listed for an element on the
periodic table is the mass of a single atom in
atomic mass units (amu)
1 amu = 1.66 x 10-24 grams
Atomic mass units are not practical for
experiments, our balances can’t measure a mass
that small
Atomic Mass
To turn amu into something
more usable in lab we use a
unit called the mole
1 mole = 6.02 x 1023 atoms
This is Avogadro’s Number
Atomic Mass = Number of
grams in 1 mol
Calculating Moles using Atomic Mass
Use atomic mass as a conversion factor
between moles and grams
How many moles are in a 10.0g sample of Carbon?
10.0 grams x 1 mole = 0.833 moles
12.01g
Try it on your own
You have 20 grams of Helium, how many moles
do you have?
Calculating Mass from Moles
You have 5 moles of Nitrogen, how many grams
do you have?
5 moles x 14.00 grams = 70 grams
1 mole
Try it on your own
You have 2 moles of Lithium, how many grams
do you have?
Matter
Pure
Substances
Elements
Compounds
& Molecules
Mixtures
Homogeneous
Heterogeneous
Solution
Review - Types of Matter
Matter is separated into two major
categories:
1) Pure substance cannot be separated
into different kinds of matter by physical
means and are made up of one single
chemical throughout
2) Mixtures are made up of multiple
substances
Most matter in the world around us are
mixtures
Compounds and Molecules
Compounds and molecules are pure
substances
They cannot be separated by physical
means but can be separated by chemical
means
Their physical and chemical properties
come from the shape of the molecule, not
from what they are made of
Compounds vs. Molecules
A molecule is ANY group of atoms
chemically bonded together
Examples:
H2 (Hydrogen Gas)
CH4 (Methane)
N2 (Nitrogen Gas)
Compounds vs. Molecules
A compound is a substance containing
DIFFERENT elements that are
chemically bonded together.
Examples:
H2O (Water)
C2H6O (Ethanol)
NaCl (Salt)
Almost everything in this world is made
of compounds!
Understanding Chemical
Formulas
Chemical formulas are written using
element symbols
Remember: Element symbols can have
either 1 or 2 letters and ALWAYS start
with a capital letter!
Chemical Formula Practice
How many different elements are in each
molecule?
NaCl
KI
HCN
KCl
MgO
Xe
Subscripts
Subscripts are used to tell you how
many copies of an element is in a
molecule
H2 = 2 Hydrogen in one element
H2O = 2 Hydrogen, 1 Oxygen in one
element
Practicing Reading Subscripts
H(CO3)2
H2SO4
How many H’s
How many H’s?
How many C’s
How many S’s?
How many O’s
How many O’s?
Molar Mass
Molar mass = Number of grams in one
mole of the molecule
You need to add up the atomic mass of
each element (multiplied by any
subscripts) to get the total mass of the
molecule
Practicing Molar Mass
Molar Mass of HCN
Mass of Hydrogen: 1.008
Mass of Carbon: 12.01
Mass of Nitrogen: 14.01
Molar Mass of H2SO4
Mass of H: 1.008 x 2
Mass of S: 32.07
Mass of O: 16.00 x 4
Molar Mass of HCN =
1.008 + 12.01 + 14.01 =
27.03 g/mol
Molar Mass of H2SO4 =
2.016 + 32.07 + 64.00 =
98.09 g/mol
Converting between grams and
moles for molecules
Converting between grams, moles, and
atoms is the same process for molecules
as it is for individual elements
Instead of using atomic mass to convert
between grams and moles you need to
use the molar mass of the molecule
Molecule Conversion Example
You have 100 grams of Table Salt (NaCl),
how many moles do you have?
100g NaCl x 1 mol NaCl = 1.71mol NaCl
58.44g NaCl
Molar Mass
Molar mass = Number of grams in one
mole of the molecule
You need to add up the atomic mass of
each element (multiplied by any
subscripts) to get the total mass of the
molecule
Percent (%) Composition
Remember from Lab 1C
% composition = mass of the part x 100
mass of the whole
We can find the Percent Composition of
a molecule the same way
Percent Composition of
Molecules
% comp = molar mass of element x 100
molar mass of molecule
Example: What percentage of the mass of
H2SO4 comes from the Oxygen?
Mass of O: 16.00 x 4 = 64 g/mol
Mass of H2SO4: 98.09 g/mol
% Oxygen: (64/98.09) x 100 = 65.2%
Percent Composition Example
Find the Percent Composition of both
Copper and Chlorine in CuCl2
Molar Mass of Copper:
Molar Mass of Chlorine:
Molar Mass of Molecule:
% composition of Copper:
% composition of Chlorine:
Matter
Pure
Substances
Elements
Compounds &
Molecules
Mixtures
Homogeneous
Heterogeneous
Solution
Mixtures
Mixtures: Matter that contains more than one
substance
Mixtures can be separated by physical means
- sorting, filtering, heating, or cooling
Types of Mixtures
Homogeneous Mixtures looks the same throughout
Heterogeneous Mixtures look different throughout
Examples of Mixtures
Decide whether each mixture is a homogeneous
mixture (HoM) or a heterogeneous mixture (HeM)
Soap
Chocolate Chip Cookie
Granite
Gatorade
Shampoo
Chex Mix
Sand
Lemonade
Granola Bar
Milk
Matter
Pure
Substances
Elements
Compounds &
Molecules
Mixtures
Homogeneous
Heterogeneous
Solution
Solutions
Solutions are a specific type of homogeneous
mixture where one substance (solute) gets
dissolved in another substance (solvent)
The substance being dissolved (the solute)
completely breaks down and gets absorbed by
the solvent:
Examples: Salt Water, Pop, lemonade