Chemistry

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Chemistry Matter Unit

• What is matter?
• What is chemistry?
• What is the organization of matter?
• What is the nature of matter?

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What is NOT Matter?

• Energy !

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Types of Energies

• Mechanical
• Chemical
• Heat
• Atomic
• Light
• Electrical

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Is Air matter?

• What are the two criteria for matter?
• Does it take up space?
• Does it have mass?

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What is chemistry?

• Chemistry is the study of the composition,
  structure, and the properties of matter and the
  changes it undergoes.
• All chemical reactions involve energy.

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What is the composition of matter?
Matter
Pure Matter Substance
Impure Matter Mixture
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What is a pure substance?

• A pure substance has a definite composition
  (proportion).
• The composition of a substance will have the same
  percent of elements no matter where the sample
  was obtained.
• Water from Lake Okechobee and water from the
  Atlantic Ocean (once cleaned up) will have the
  same composition of hydrogen to oxygen.
• Gold is the same as other gold (once cleaned up).

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What is a pure substance?

• A pure substance, by definition, is an element or
  a compound.
• A container with an almost pure compound

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Pure Substance
Pure Substance
Compound
Element
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What is an element?

• a pure substance made of only one kind of atom
• A substance that cannot be decomposed any farther
  by simple chemical means
• An element has a definite composition. Gold from
  South Africa is the same, when purified, as a
  sample from California.

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Periodic Table of Elements

• Most elements on the periodic chart are metals.
• Elements through 114 but not 113 have been
  discovered or made.

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Elemental Samples

• Zinc, copper, lead, carbon, sulfur

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What is a compound?

• A compound is a substance that is made from the
  atoms of two or more elements that are chemically
  bonded.
• The definition is actually more involved than
  this.

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What is a compound?

• A compound is a substance that cannot be
  decomposed any farther by simple physical means.
• A compound has a definite composition by mass.
• A compound is made up of two or more elements
  chemically combined.

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What is a compound?

• A compound no longer has the properties of its
  constituent elements.
• Table salt, NaCl or sodium chloride, is a
  compound of the element sodium and the element
  chlorine.

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Sodium
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Sodium metal

• Soft, can be cut with a knife
• Shiny
• Good conductor of electricity
• Very reactive

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Sodium in water
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Chlorine gas
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Chlorine gas

• Greenish gas
• Poisonous
• Heavier than air

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Sodium in chlorine gas
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Sodium chloride, NaCl

• Sodium chloride dissolves in water rather than
  reacts with water.
• Sodium chloride is a white solid, not a poisonous
  green gas.
• Sodium chloride is its own substance with its own
  properties, not those of either sodium or
  chlorine.

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Samples of Other Compounds

• Sucrose (table sugar), Sodium Chloride, Water,
  Copper(II) sulfate

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Colored Compounds

• Cobalt(II) chloride, Iron(II) sulfate, Potassium
  dichromate, Potassium chromate, Nickel(II)
  nitrate, copper(II) sulfate

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What is the composition of matter?

• Matter

Pure Substance
Impure Matter Mixture
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Impure Matter - Mixture

• A mixture is a blend of two or more kinds of
  matter, each of which retains its own identity
  and properties.
• A mixture is made up of two or more substances
  that are not chemically combined.

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Mixtures

• Mixtures can be separated by simple physical
  means.
• Two mixtures containing the same substances may
  not have the same proportions.
• Example Very salty water versus barely salty
  water. Very sweet sugar water versus slightly
  sweet sugar water.

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Water and Dye Mixture

• Two mixtures of the same substances may have
  different proportions.

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Mixtures
Mixtures
Homogeneous Mixture
Heterogeneous Mixture
?
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Solutions

• Mixtures
• Mixture a blend of two or more kinds of
  matter, each of which retains its own identity
  and properties
• a) homogeneous mixture a mixture that is
  uniform in composition throughout
• Ex Food coloring and water
• b) heterogeneous mixture a mixture that is NOT
  uniform in composition throughout
• Ex Oil and water

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Heterogeneous Mixtures

• Sand and water on the left and sand and gravel on
  the right.

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Heterogeneous Mixture
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Types of Mixtures

• 1) solution a homogeneous mixture
• 2) suspension a mixture in which the particles
  are so large that they settle out unless the
  mixture is constantly stirred or agitated
• Heterogeneous mixture
• Ex Sand and water

3) colloid a mixture consisting of particles
that are intermediate in size between those in
solutions and those in suspensions
Heterogeneous mixture Ex Milk
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Colloidal Suspension

• Fog

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Tyndall Effect
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THE NATURE OF SOLUTIONS

• Solvent the substance that does the dissolving
  in a solution
• a) Typically present in the greatest amount
• b) Typically a liquid
• c) Water is the most common or universal
  solvent
• 2) Solute substance being dissolved in a
  solution
• a) Typically present in the least amount
• b) Typically a solid

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9 Possible Solution Combinations
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Factors Affecting the Rate of Dissolving
(Increase Solution Rate)

• 1) Grinding increases surface area
• 2) Stirring allows solvent continual contact
  with solute
• 3) Heating increases kinetic energy increases
  mixing

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SOLUBILITY

• 1) Solubility quantity of solute that will
  dissolve in specific amount of solvent at a
  certain temperature.
• (pressure must also be specified for gases).
• Ex 204 g of sugar will dissolve in 100 g of
  water at 20C
• soluble and insoluble are relative terms
• solubility should NOT be confused with the rate
  at which a substance dissolves
• 2) saturated solution a stable solution in
  which the maximum amount of solute has been
  dissolved.

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• 3) solution equilibrium state where the solute
  is dissolving at the same rate that the solute is
  coming out of solution (crystallizing).
• a) Opposing processes of the dissolving and
  crystallizing of a solute occur at equal rates.
• b) solute solvent solution

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• 4) unsaturated solution a solution that
  contains less solute than a saturated solution
  under existing conditions
• 5) supersaturated solution a solution that
  temporarily contains more than the saturation
  amount of solute than the solvent can hold
  (unstable)

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3 FACTORS EFFECTING SOLUBILITY

• The extent to which a given solute dissolves in a
  solvent depends on the identity of the solute and
  solvent and also on the existing conditions of
  pressure temperature

• 1) Nature of solute and solvent
• Like dissolves like rule of thumb for
  predicting whether or not one substance dissolves
  in another
• Alikeness depends on
• o Intermolecular forces
• o Type of bonding

o Polarity or nonpolarity of molecules
ionic solutes tend to dissolve in polar
solvents but not in nonpolar solvents
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Solvent-Solute Combinations
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2) Pressure a)Pressure has little effect on the
solubility of liquids or solids in liquid
solvents. b)The solubility of a gas in a liquid
solvent INCREASES when pressure increases. It is
a direct relationship.
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3) Temperature a)The solubility of a gas in a
liquid solvent DECREASES with an increase in
temperature. b)The solubility of a solid in a
liquid solvent MOST OFTEN increases with an
increase in temperature. However, solubility
changes vary widely with temperature changes
sometimes decreasing with temperature increases.
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Mixtures vs. Compounds

• Rocks are mixtures.
• Minerals are pure substances
• Granite rock

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Mixtures vs Compounds

• Minerals are pure substances although many have
  impuities that must be cleaned up first.

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Minerals
Amethyst Halite Diamond
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What is the nature of matter?

• An atom is the smallest unit of an element that
  maintains the properties of that element
• An atom is made up of electrons, protons, and
  neutrons as well as other particles.
• Protons and neutrons are made up of quarks.

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What is the nature of matter?

• A molecule is a unit that consists of more than
  one atom bonded together.
• A molecule can have atoms of the same element
  such as oxygen. These are called diatomic
  elements.

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Blue diatomic elements
Diatomic elements blue Tetraatomic element
red Octatomic element - yellow
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What is the nature of mature?

• A molecule can have atoms of more than one type
  of element.
• Water
• Sugar (sucrose)

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Atoms and Molecules

• Three particles
• 2 atoms of hydrogen
• 1 atom of oxygen
• One particle
• 1 molecule of water

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Atoms

• How can an atom of an element be broken up into
  atoms of other elements or into other smaller
  particles and energy?
• Nuclear Reaction

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Compound

• How is a compound broken up into its elements or
  other simpler compounds?
• Use a chemical separation method.
• What are some examples of chemical separation
  methods?

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Chemical Separation Methods

• Heat the compound.

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Chemical Separation Methods

• Use Electrolysis which is using an electric
  current to decompose the compound.
• An electrolyte has been added to the water since
  water does not conduct.

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Mixtures

• How can mixtures be separated?
• Use Physical Separation Methods.
• What are examples of physical separation methods?

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Physical Separation Methods

• Distillation is the separation of mixtures by
  using the difference in boiling points of
  liquids.
• A water cooled condenser is used.

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Physical Separation Methods

• Filtration uses the difference in particle size
  to separate mixtures.
• Filter papers have different size pores.

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Physical Separation Methods

• Chromatography uses the difference in solubility
  in various solvents.
• Gas, liquid, thin layer, and paper chromatography
  are widely used.

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States of Matter

• Three states of matter
• Liquid, solid, gas

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Physical Changes

• During physical changes matter changes in
  appearance without forming new substances.
• What some examples of physical changes?

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Physical Change Examples

• Breaking or tearing

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Physical Change Examples

• Boiling or condensing

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Physical Change Examples

• Freezing or melting

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Physical Change Examples

• Sublimation

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Physical Change Examples

• Sublimation
• The change of state directly to a gas is known
  as sublimation.
• The reverse process is called deposition, the
  change of state from a gas directly to a solid.

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Chemical Changes

• During chemical changes new substances are formed
  with different properties than the original
  substances.
• What is an example of a chemical change?

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Chemical Change Example

• Heating baking soda, sodium hydrogen carbonate,
  forms sodium carbonate, carbon dioxide, and
  water. The formation of carbon dioxide is what
  causes cakes to rise.

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Mixture or Pure Substance

• These bottles contain sodium chloride, sucrose,
  and a mixture of the two. Which is which and how
  can they be identified?

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Physical and Chemical Properties

• What are some physical properties of this pen?

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Physical Properties

• Examples
• Color
• Hardness
• Texture
• Volume
• Length
• Mass

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Physical Properties

• More Examples
• Density (mass/volume ratio)
• Odor
• Sound
• Boiling point
• Melting point
• Magnetism

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Physical Properties

• Melting Point and freezing point temperatures are
  the same.

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Chemical Properties

• A chemical property is how something reacts.
• Does the pen float is physical.
• Does the pen dissolve is physical.
• Does the pen react with water is chemical.

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Chemical Properties

• Does the pen burn is a chemical property.
• Whether and how something reacts is chemical.

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Extensive vs Intensive

• Extensive Properties depend upon the amount of
  matter that is present.
• Intensive Properties do not depend on the amount
  of matter present. These properties are the same
  for a given substance regardless of how much of
  the substance is present.

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Extensive vs Intensive

• Which of the properties listed earlier are
  extensive and which are intensive?
• Comparisons of several properties are used
  together to identify an unknown.

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Matter Unit

• Now it is time to try Chemistry Vocabulary
  Worksheet Application of Matter.
• .

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Chemistry Vocabulary

• A Symbol is a representation of an element.
• One or two letters may be used.
• The first letter is upper case while the second
  is lower case.

H C O Fe Cl Ag Cu Ba Cf
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Chemistry Vocabulary

• A formula is a representation of a molecule of an
  element or a molecule of a compound.

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Chemistry Vocabulary

• The subscript represents the number of atoms of a
  particular element in the molecule.

12 atoms of carbon 22 atoms of hydrogen 11 atoms
of oxygen
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Chemistry Vocabulary

• If no subscript is shown. An understood one is
  indicated.

2 atoms of hydrogen 1 atom of sulfur 4 atoms of
oxygen
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Chemistry Vocabulary

• A coefficient is a number in front of a formula
  and represents the number of molecules.
• If no coefficient is shown, one molecule is
  indicated.

2 molecules of sucrose 24 atoms of carbon 44
atoms of hydrogen 22 atoms of oxygen
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Chemistry Vocabulary

• An equation is a sentence showing what is
  happening in a chemical reaction.

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Chemistry Vocabulary

• The reactants are the substances (elements or
  compounds) that will react. They are on the left
  or starting side.

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Chemistry Vocabulary

• The products on the right side of the equation
  are what are formed or are produced during the
  reaction.

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Chemistry Vocabulary

• An atom is the smallest unit of an element that
  maintains the properties of that element
• An atom is made up of electrons, protons, and
  neutrons as well as other particles.
• Protons and neutrons are made up of quarks.

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Chemistry Vocabulary

• A atom is made up of a nucleus and particles
  outside the nucleus called electrons.
• Electrons are negatively charged particles.
• The mass of an electron is about 1800 times
  smaller than that of the proton and neutron.

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Chemistry Vocabulary

• The nucleus is the tiny positive core of the
  atom.
• Two of the particles in the nucleus are the
  proton and the neutron.
• The proton is a positively charged particle.

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Chemistry Vocabulary

• What is wrong with this commonly used picture?
• The nucleus is 1/10000 times smaller than the
  atom.
• The atom is mostly empty space.

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Chemistry Vocabulary

• Proton
• The charge on a proton is equal in magnitude but
  opposite in sign to the charge on an electron.
• A proton is made up of three quarks.
• Two quarks have a 2/3 charge.
• One quark has a -1/3 charge.

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Chemistry Vocabulary

• The mass of a proton is approximately 1800 times
  heavier than an electron.
• The number of protons present is what
  determines the type of atom.
• If the number of protons change, an atom of a
  different element is formed.

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Chemistry Vocabulary

• The number of protons found in the nucleus is
  known as the atomic number.
• Hydrogen with an atomic number of 1 has only one
  proton. If it had 2, it would be helium.
• Uranium with an atomic number of 92 has 92
  protons.

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Chemistry Vocabulary

• A neutron is an uncharged particle found in the
  nucleus.
• The mass of a neutron is almost the same as the
  mass of a proton.
• A neutron is made of three quarks.
• One quark has a 2/3 charge.
• Two quarks have a -1/3 charge.

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Chemistry Vocabulary

• Two atoms of the same element can have differing
  numbers of neutrons. These are called isotopes.
• Hydrogen has three isotopes
• Hydrogen with 1 proton and 0 neutrons
• Deuterium with 1 proton and 1 neutron
• Tritium with 1 proton and 2 neutrons

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Chemistry Vocabulary

• The different masses of these isotopes give them
  different properties such as melting and boiling
  points and reactivities and stabilities.
• Regular uranium is not radioactive enough for a
  nuclear fuel. Only certain isotopes of uranium
  will work.

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Chemistry Vocabulary

• The mass number is the total number of protons
  and neutrons in the nucleus of the atom.
• The mass number is not found on the periodic
  table.
• The masses on the table are the weighted averages
  of the isotopes.

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Chemistry Vocabulary
Particle Symbol Charge Mass Number
Electron 1- 0
Proton 1 1
Neutron 0 1
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Chemistry Vocabulary

• Nuclear Symbol
• Mass Number
• Number of protons and neutrons
• Atomic number
• Number of protons
• Found on Periodic Table

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Chemistry Vocabulary

• Number of protons
• 17
• Number of neutrons
• 18
• Number of electrons
• 17
• The number of protons number of electrons

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Chemistry Vocabulary

• Number of protons
• 12
• Number of neutrons
• 13
• Number of electrons
• 12

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Chemistry Vocabulary

• In a neutral atom the number of protons is equal
  to the number of electrons.
• The number of protons can never vary in an atom.
• The electrons are the particles that can be
  gained or lost in a reaction.

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Chemistry Vocabulary

• The sum of the positive protons and the negative
  electrons give the overall charge of the atom.
• The term charge was once called valence.
• The charge is shown as a superscript to the upper
  right.

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Chemistry Vocabulary

• Number of protons
• 17
• Number of neutrons
• 19
• Number of electrons
• 18
• (17) (?-) 1-
• So ? 18-

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Chemistry Vocabulary

• Number of protons
• 12
• Number of neutrons
• 12
• Number of electrons
• 10
• (12) (?-) 2
• ?- 10

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Chemistry Vocabulary

• An ion is a charged atom or group of atoms.
• A cation is a positively charged ion.
• An anion is a negatively charged ion. The prefix
  an- can mean not or negative.

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Chemistry Vocabulary

• Free state The atom or molecule is not combined
  with atoms of other elements.
• Gold can be found in the free state.
• Because of its reactivity, sodium cannot.
• Combined state The atom is part of a compound.

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Matter Unit

• Now it is time to try Chemistry Vocabulary
  Worksheet Application of Matter.
• The exam will cover the material in this unit,
  the lab safety material, and the lab drawer
  equipment.
• Know the examples and how the ideas go together.
  Know all parts of the definitions.