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  • Slide 1
  • Chemistry and Life
  • Slide 2
  • The Periodic Table Atomic Number: Number of Protons and Electrons Atomic mass: Mass relative to Carbon-12
  • Slide 3
  • Chemical Bonding HUGE: ONLY THE ELECTRONS ARE INVOLVED IN MAKING CHEMICAL BONDS!!! More specifically, the only the ones on the outermost shell
  • Slide 4
  • Covalent Bond Covalent bonds are generally when two or more atoms share one or more pairs of electrons.
  • Slide 5
  • Nonpolar Covalent Bond when these shared pairs of electrons are shared EQUALLY!
  • Slide 6
  • Polar Covalent Bond when these shared pairs of electrons are NOT shared equally!
  • Slide 7
  • Common Polar Covalent Bond???
  • Slide 8
  • Ionic Bond bond formed between oppositely charged ions. This happens when the stronger atom steals 1+ electrons from the weaker atom. They both have their outer shells filled, so all is good.
  • Slide 9
  • Ions Cl- is such a beast that it pulls the outer electron from Na. Now both are happy. They are both now ions. Chlorine Sodium
  • Slide 10
  • Hydrogen Bonds These are weak bonds that are caused by the weak positive charge of the hydrogen atom to other negative atoms.
  • Slide 11
  • Solutes and Solvents Which is the solute and which is the solvent?
  • Slide 12
  • Solutes and Solvents Solute: The stuff the gets dissolved Solvent: The stuff that does the dissolving
  • Slide 13
  • The Mole: A Measurement of Matter OBJECTIVES: Distinguish between the atomic mass of an element and its molar mass.
  • Slide 14
  • How do we measure items? You can measure mass, or volume, or you can count pieces. We measure mass in grams. We measure volume in liters. We count pieces in MOLES.
  • Slide 15
  • What is the mole? Were not talking about this kind of mole!
  • Slide 16
  • Moles (is abbreviated: mol) It is an amount, defined as the number of carbon atoms in exactly 12 grams of carbon-12. 1 mole = 6.02 x 10 23 of the representative particles. Treat it like a very large dozen 6.02 x 10 23 is called: Avogadros number.
  • Slide 17
  • Similar Words for an amount Pair: 1 pair of shoelaces = 2 shoelaces Dozen: 1 dozen oranges = 12 oranges Gross: 1 gross of pencils = 144 pencils Ream: 1 ream of paper = 500 sheets of paper
  • Slide 18
  • Examples Calculate the molar mass of the following and tell what type it is: Na 2 S N 2 O 4 C Ca(NO 3 ) 2 C 6 H 12 O 6 (NH 4 ) 3 PO 4 = 78 g/mol gram formula mass = 92 g/mol gram molecular mass = 12 g/mol gram atomic mass = 164 g/mol gram formula mass = 180 g/mol gram molecular mass = 149 g/mol gram formula mass
  • Slide 19
  • For example How many moles is 5.69 g of NaOH?
  • Slide 20
  • For example How many moles is 5.69 g of NaOH? l We need to change 5.69 grams NaOH to moles
  • Slide 21
  • For example How many moles is 5.69 g of NaOH? l We need to change 5.69 grams NaOH to moles l 1mole Na = 23 g 1 mol O = 16 g 1 mole of H = 1 g
  • Slide 22
  • For example How many moles is 5.69 g of NaOH? l We need to change 5.69 grams NaOH to moles l 1mole Na = 23 g 1 mol O = 16 g 1 mole of H = 1 g l 1 mole NaOH = 40 g
  • Slide 23
  • For example How many moles is 5.69 g of NaOH? l We need to change 5.69 grams NaOH to moles l 1mole Na = 23 g 1 mol O = 16 g 1 mole of H = 1 g l 1 mole NaOH = 40 g
  • Slide 24
  • For example How many moles is 5.69 g of NaOH? l We need to change 5.69 grams NaOH to moles l 1mole Na = 23 g 1 mol O = 16 g 1 mole of H = 1 g l 1 mole NaOH = 40 g
  • Slide 25
  • Chemical Reactions An Overview
  • Slide 26
  • How do you know a reaction has taken place? A new substance is formed Heat is produced or absorbed A gas is released
  • Slide 27
  • How to write a reaction Example: Hydrogen gas + Oxygen gas = Water
  • Slide 28
  • Here ya go! H 2 + O 2 H 2 O Reactants Products H 2 and O 2 H 2 O
  • Slide 29
  • Types of Reactions Synthesis: 2 or more substances combine to make a new one. Example: H 2 + O 2 H 2 O
  • Slide 30
  • Decomposition: 1 substance is broken into 2 or more substances H 2 O H 2 + O 2
  • Slide 31
  • Single Displacement: One element replaces another element. Cu + AgNO 3 CuNO 3 + Ag The Silver replaced the Copper Demo
  • Slide 32
  • Double Displacement: Two elements switch places. Two Ions are mixed together and a precipitate is formed A precipitate is an insoluble compound formed during the reaction PbNO 3 + KI PbI 2 + KNO 3
  • Slide 33
  • OXIDATION/ REDUCTION STUFF OXIDATION: LOSS OF ELECTRONS EXAMPLE: SODIUM IN THE PRESENCE OF CHLORINE REDUCTION: GAIN OF ELECTRONS EXAMPLE: CHLORINE IN THE PRESENCE OF SODIUM ***THE TWO REACTIONS ALWAYS OCCUR TOGETHER!!
  • Slide 34
  • What the heck is pH? ACID: PROTON DONOR (BASICALLY, A DONATION OF H + IONS. WHAT IS H + REALLY? BASE: PROTON ACCEPTOR; RELEASES OH IONS
  • Slide 35
  • More on pH IT IS SIMPLE THE LOG OF THE INVERSE OF THE HYDROGEN ION CONCENTRATION. (NOW, IN ENGLISH): THE LOWER THE pH, THE HIGHER THE [H+], THE HIGHER THE pH, THE LOWER THE [H+]. EACH SCALE NUMBER OF pH REPRESENTS A TENFOLD INCREASE OR DECREASE IN THE [H+].
  • Slide 36
  • EXAMPLE: HOW MUCH MORE ACIDIC IS pH=2 AS COMPARED TO pH=4? Answer: 100x (10x10) Answer= 10 x 10 = 100 Answer: 100x (10x10)
  • Slide 37
  • BUFFERS BUFFERS: THEY RESIST A CHANGE IN pH OF A SUBSTANCE BY EITHER ACCEPTING OR DONATING H+ IONS IN THE PRESENCE OF AN ACID OR A BASE

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