CHEMISTRY

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CHEMISTRY

• Chapter 2

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Composition of Matter
Chemistry
Water and Solutions
Energy
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I. Composition of Matter

• Matter
• occupies space
• has mass
• Mass quantity of matter
• Chemical changes are essential to all life
  processes

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I. Composition of Matter

• Atom- indivisible
• Protons
• Neutrons NC
• Electrons -
• Element- 1 type of atom
• Expressed as symbol Na, Cl, C, H
• Atomic number
• Atomic mass
• Mass number
• Isotopes
• Ions
• Periodic Table of Elements e- Trends

Nucleus
6 C Carbon 12.011
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Ions
Isotopes
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Lithium Neon Li Ne
Hydrogen Helium H He
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I. Composition of Matter

• Compound 2 or more elements
• Expressed as formula NaCl, O2
• Bonds stored energy, broken bonds released
• Ionic bonds transfer e-
• Covalent bonds share e-
• Chemical Reactions new substance(s) result
• Expressed as chemical equations
• 2H2 O2 ? 2H2O
• Reactants ? Products
• Reactants starting materials
• Products end result
• Arrow yields (direction of reaction)

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Covalent Bonding O O ? O2
Ionic Bonding
Covalent Bonding H2 O ? H2O
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II. Energy

• Energy Matter
• Energy ability to do work cause change
• Free energy
• Energy forms electrical, chemical, light, etc.
• States of Matter solid, liquid, gas

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II. Energy

• Energy Chemical Reactions
• Chemical reactions rely on the conversion of
  energy from 1 form to another (e.g.
  photosynthesis)
• Types of reactions
• Exergonic release
• Endergonic absorbs
• Activation Energy to start rxn
• Catalysts lower A.E

Enzymes catalysts in living things
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Exergonic
Endergonic
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Activation Energy
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II. Energy

• Redox rxns Oxidation Reduction
• Oxidation Rxn loss of electrons (e-)
• Na ? Na e-
• Reduction Rxn gaining e-
• Cl e- ? Cl-
• Oxidation rxns always occur with reduction
  rxns, hence REDOX!!!

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III. Water and Solutions

• Polarity uneven distribution of charge
• Hydrogen Bonding
• 1.Cohesion same
• High specific heat
• 2. Adhesion different
• Universal Solvent
• Capillarity

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III.Water and Solutions

• C. Solution- mixture in which particles are
  uniformly distributed
• Solute is dissolved
• Solvent does dissolving
• Concentration how much solute is dissolved in a
  fixed amt of solvent
• Saturated max amt of solute
• Unsaturated less than max
• E.g. salt water, sugar water, rock candy
• Aqueous solution H2O solvent

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III. Water and Solutions (con)

• D. Acids Bases
• Dissociation molecule splitting into 2 ions
  (e.g. H2O ? H OH-)
• Acid H gt OH- in solution acidic
• HCl ? H Cl-
• Base H lt OH- in solution alkaline
• NaOH ? Na OH-

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III. Water and Solutions

• E. pH scale scale for H (A.K.A. acidic or
  basic solution)
• Measures changes in H by tenfold
• Range is 0-14
• Acid 0- 6.9 (lower stronger acid)
• Neutral 7
• Basic 7.1-14 (higher stronger base)
• Litmus paper chemical indicators
• F. Buffers chemical substances added to solution
  that can neutralize acids or bases (e.g. NaHCO3)
• How is pH related to homeostasis?

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pH Scale