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CHEMISTRY COMES ALIVE

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CHEMISTRY COMES ALIVE

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CHEMISTRY COMES ALIVE

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  1. CHEMISTRY COMES ALIVE BASIC CHEMISTRY

  2. DEFINITION OF CONCEPTS MATTER AND ENERGY

  3. MATTER • ANYTHING THAT HAS MASS AND OCCUPIES SPACE • MASS=AMOUNT OF MATTER IN THE OBJECT • MASS REMAINS CONSTANT REGARDLESS OF GRAVITY

  4. STATES OF MATTER • SOLID • LIQUID • GAS

  5. ENERGY • ENERGY IS THE CAPACITY TO DO WORK AND EXISTS IN 2 FORMS • KINETIC ENERGY – ENERGY OF MOTION • POTENTIAL ENERGY – STORED ENERGY

  6. FORMS OF ENERGY • CHEMICAL ENERGY – ENERGY STORED IN CHEMICAL BONDS • ELECTRICAL ENERGY – RESULTS FROM MOVEMENT OF CHARGED PARTICLES • MECHANICAL ENERGY – INVOLVED WITH MOVING MATTER • RADIANT ENERGY – ENERGY THAT TRAVELS IN WAVES • ENERGY CAN BE CONVERTED FROM ONE FOR TO ANOTHER

  7. COMPOSITION OF MATTER ATOMS AND ELEMENTS

  8. BASIC TERMS • ELEMENTS CANNOT BE BROKEN DOWN INTO SIMPLER SUBSTANCES BY ORDINARY CHEMICAL MEANS • C,H,O,AND N – 96% OF BODY WEIGHT • ATOMS – SMALLEST PARTICLES OF AN ELEMENT THAT RETAIN THE CHARACTERISTICS OF THAT ELEMENT • ELEMENTS ARE DESIGNATED BY 1 OR 2 LETTER ATOMIC SYMBOLS

  9. ATOMIC STRUCTURE • ATOM HAS NUCLEUS WITH PROTONS(+, 1 AMU) AND NEUTRONS(NO CHARGE, 1 AMU) • ELECTRONS – HAVE A NEG. CHARGE AND MOVE AROUND THE NUCLEUS.(0 AMU) • ATOMS ARE ELECTRICALLY NEUTRAL (PRO. = ELEC.) • PLANETARY MODEL – 2-D • ORBITAL MODEL – 3-D

  10. IDENTIFYING ELEMENTS • ELEMENTS ARE IDENTIFIED BASED ON THEIR NUMBER OF P,N, AND E.

  11. ATOMIC NUMBER • ATOMIC NUMBER = # OF PROTONS • SINCE # PROTONS = # ELECTRONS IN AN ELECTRICALLY NEUTRAL ATOM, THE ATOMIC # ALSO TELLS US # OF ELECTRONS

  12. MASS # AND ISOTOPES • MASS # = PROTONS + NEUTRONS • ELECTRON IS WEIGHTLESS SO IT IS IGNORED WHEN CALCULATING MASS # • ISOTOPES – VARIATIONS OF AN ATOM THAT HAVE THE SAME NUMBER OF PROTONS, BUT DIFFERING NUMBERS OF NEUTRONS

  13. ATOMIC WEIGHT • AVERAGE OF THE RELATIVE WEIGHTS OF ALL OF THE ISOTOPES OF AN ELEMENT

  14. RADIOISOTOPES • HEAVIER, UNSTABLE ISOTOPES OF AN ELEMENT THAT SPONTANEOUSLY DECOMPOSE INTO MORE STABLE FORMS • TIME REQUIRED FOR A RADIOACTIVE ISOTOPE TO LOSE ONE-HALF OF ITS RADIOACTIVITY IS CALLED THE HALF-LIFE

  15. HOW MATTER IS COMBINED MOLECULES AND MIXTURES

  16. MOLECULES AND COMPOUNDS • MOLECULE – A COMBINATION OF TWO OR MORE ATOMS • 2 OR MORE ATOMS OF THE SAME ELEMENT IS CALLED A MOLECULE OF THAT ELEMENT • COMPOUND – 2 OR MORE ATOMS OF DIFFERENT ELEMENTS COMBINED

  17. MIXTURES • SUBSTANCES MADE OF 2 OR MORE COMPONENTS MIXED PHYSICALLY • SOLUTIONS ARE HOMOGENEOUS MIXTURES OF COMPOUNDS THAT MAY BE SOLID, LIQUID, OR GAS • SOLUTIONS HAVE SOLVENTS AND SOLUTES • MAY BE DESCRIBED BY THEIR CONCENTRATIONS (MOLARITY)

  18. MIXTURES CONT. • COLLOIDS – HETEROGENEOUS MIXTURES • SUSPENSIONS – HETEROGENEOUS MIXTURES WITH LARGE, OFTEN VISIBLE SOLUTES THAT TEND TO SETTLE OUT

  19. DISTINGUISHING MIXTURES AND COMPOUNDS • MAIN DIFFERENCE – NO CHEMICAL BONDING BETWEEN MOLECULES OF A MIXTURE • MIXTURES CAN BE SEPARATED BY PHYSICAL MEANS, COMPOUNDS MUST BE SEPARATED BY CHEMICAL MEANS • HOMOGENEOUS VS. HETEROGENEOUS

  20. CHEMICAL BONDS • AN ENERGY RELATIONSHIP BETWEEN THE ELECTRONS OF REACTING ATOMS

  21. ROLE OF ELECTRONS IN CHEMICAL BONDING • ELECTRONS OCCUPY ELECTRON SHELLS AROUND THE NUCLEUS THAT REPRESENT DIFFERENT ENERGY LEVELS • EACH ELECTRON SHELL HOLDS A SPECIFIC # OF ELECTRONS AND TEND TO BE FILLED FROM CLOSEST TO THE NUCLEUS OUT. • EXCEPT FOR THE 1ST ENERGY LEVEL, ATOMS ARE STABLE WITH EIGHT ELECTRONS IN THEIR VALENCE SHELL (THE OCTET RULE)

  22. TYPES OF CHEMICAL BONDS

  23. IONIC BONDS • CHEMICAL BONDS THAT TRANSFER ONE OR MORE ELECTRONS FROM ONE ATOM TO ANOTHER • IONS ARE CHARGED PARTICLES, EITHER ANIONS (NEG) OR CATIONS (POS) • CRYSTALS ARE LARGE STRUCTURES OF CATIONS AND ANIONS HELD TOGETHER BY IONIC BONDS.

  24. COVALENT BONDS • SHARE ELECTRONS • NONPOLAR COVALENT BONDS – SHARE ELECTRONS EVENLY • POLAR COVALENT BONDS – SHARE ELECTRONS UNEVENLY (OFTEN REFERRED TO AS A DIPOLE)

  25. HYDROGEN BONDS • WEAK ATTRACTIONS THAT FORM BETWEEN PARTIALLY CHARGED ATOMS FOUND IN POLAR MOLECULES • HYDROGEN BONDS BETWEEN WATER MOLECULES CAUSES SURFACE TENSION

  26. CHEMICAL REACTIONS • OCCUR WHENEVER BONDS ARE FORMED, REARRANGED, OR BROKEN • A CHEMICAL EQUATION DESCRIBES WHAT HAPPENS IN A REACTION • INCLUDES REACTANTS AND PRODUCTS • MUST BE BALANCED

  27. PATTERNS OF CHEMICAL REACTIONS • SYNTHESIS (COMBINATION) RXN – LARGER MOLECULES ARE FORMED FROM SMALLER MOLECULES • DECOMPOSITION RXN – A MOLECULE IS BROKEN DOWN INTO SMALLER MOLECULES • EXCHANGE (DISPLACEMENT) RXN – INVOLVE BOTH SYN. AND DECOMP. • OXIDATION-REDUCTION RXN – SPECIAL ECHANGE RXNS IN WHICH ELECTRONS ARE EXCHANGED BETWEEN REACTANTS

  28. ENERGY FLOW IN CHEM. RXNS • EXERGONIC RXNS RELEASE ENERGY AS A PRODUCT, WHILE ENDERGONIC RXNS ABSORB ENERGY

  29. REVERSIBILITY OF CHEMICAL RXNS • ALL CHEM RXNS ARE THEORETICALLY REVERSIBLE • WHEN THE RATE OF THE FORWARD RXN = THE RATE OF THE REVERSE RXN, THE RXNS HAVE REACHED A CHEMICAL EQUILIBRIUM

  30. FACTORS INFLUENCING RATE OF CHEMICAL RXNS • CHEMICALS REACT WHEN THEY COLLIDE WITH ENOUGH FORCE TO OVERCOME THE REPULSION BY THEIR ELECTRONS • INCREASE IN TEMP. INCREASES RATE • SMALLER PARTICLES – FASTER RATE • HIGHER CONCENTRATION OF REACTANTS – FASTER RATE • CATALYSTS INCREASE RATE WITHOUT TAKING PART IN THE RXN

  31. BIOCHEMISTRY INORGANIC COMPOUNDS

  32. WATER • MOST IMPORTANT INORGANIC MOLECULE, MAKES UP 60 TO 80% OF THE VOLUME OF MOST LIVING CELLS • HAS A HIGH HEAT CAPACITY • HIGH HEAT OF VAPORIZATION • POLAR MOLECULE • UNIVERSAL SOLVENT • IMPORTANT REACTANT • FORMS A PROTECTIVE CUSHION AROUND ORGANS

  33. SALTS • IONIC COMPOUNDS • WHEN DISSOLVED IN WATER, THEY DISSOCIATE INTO THEIR COMPONENT IONS

  34. ACIDS AND BASES • ACIDS – AKA PROTON DONORS, DISSOCIATE IN H2O TO YIELD HYDROGEN IONS AND ANIONS • BASES – AKA PROTON ACCEPTORS, ABSORB HYDROGEN IONS • PH UNITS – RELATIVE CONCENTRATION OF HYDROGEN IONS • GREATER HYDROGEN ION CONCENTRATION – ACIDIC • GREATER HYDROXYL ION CONCENTRATION – BASIC (ALKALINE)

  35. ACIDS AND BASES CONT. • NEUTRALIZATION – WHEN AN ACID AND A BASE ARE MIXED TOGETHER. DISPLACEMENT REACTION THAT FORMS SALT AND WATER • BUFFERS – RESIST LARGE FLUCTUATIONS IN PH THAT WOULD BE DAMAGING TO LIVING TISSUES

  36. BIOCHEMISTRY ORGANIC COMPOUNDS

  37. CARBOHYDRATES • GROUP OF MOLECULES INCLUDING SUGARS AND STARCHES • CONTAIN CARBON, HYDROGEN, AND OXYGEN • MAIN FUNCTION IS TO PROVIDE CELLULAR FUEL • MONOSACCHARIDES ARE SINGLE RING STRUCTURES (SIMPLE SUGARS) • DISACCHARIDES – 2 MONOSACCHARIDES JOINED BY DEHYDRATION SYNTHESIS • POLYSACCHARIDES – LONG CHAINS OF MONOSACCHARIDES JOINED BY DEHYDRATION SYNTHESIS