TOPICS:
VALENCE, CHEMISTRY DEFINITIONS, ELECTRON DOT DIAGRAM
CHEMICAL BONDING, ELECTRONEGATIVITY, MOLECULAR SHAPE
PHYSICAL BONDING, CHEMICAL PROPERTIES OF WATER
CHEMICAL RXTS: ACIDS AND BASES AND BUFFERS
CHEMICAL RXTS P2: REDOX RXTS
CHEMICAL RXTS P3: MAKING/BREAKING CHEMICAL BONDS- HYDROLYSIS AND DEHYDRATION SYNTHESIS RXTS
Slide 2
CHEMISTRY DEFINITIONS-DEFINITIONS
ATOMS: SMALLEST PARTICLE OF MATTER SUB-ATOMIC PARTICLES: P+(NUCLEUS), NEUTRONS(NUCLEUS), E-(ORBITS)MOLECULE: 2+ ATOMS CHEMICALLY JOINED TOGETHER AKA A BOND EXISTS BETWEEN THE TWOCPD: 2+ ATOMS BONDED TOGETHER IN FIXED RATIOPURE SUBSTANCE: CONTAINS ONLY ONE TYPE OF ATOM OR MOLECULEMIXTURE: 2+ ELEMENTS MIXED AND AMOUNT DOESN'T MATTERSOLUTION: CONTAINS SOLUTE(GETS DISSOLVED) AND SOLVENT(DOES DISSOLVING) ONE VISIBLE LAYER, HOMOGENOUS "LIKE DISSOLVES LIKE"SUSPENSION: ONE SUBSTANCE FLOATING, PARTICLES SEPARATE WHEN LEFT ALONE, HETEROGENOUS. ION: ATOM THAT'S LOST/GAINED AND E-. TYPES: ANION(GAINED SO NEG CHARGE) AND CATION(LOST SO POS CHARGE)ISOMERS: SAME CHEM. FORMULA BUT DIFF. CHEM. STRUCTURES(GLUCOSE & FRUCTOSE)ISOTOPES: SAME ELEMENT BUT DIFFERENT NEUTRONS, THIS MAKES THEM UNSTABLE & RADIOACTIVE. HALF-LIFE: ISOTOPES THAT BREAK DOWN AT A FIXED RATE(TIME REQUIRED FOR HALF OF THE MASS TO BREAK APART)CARBON-14 DATING: THIS IS WHEN YOU DETERMINE THE AGE IN ALL LIVING THINGSMEDICAL LABS & TRACERS: HIGHLIGHT CERTAIN ORGANS (TUMORS)SHORT LIFE SPANS TO PROTECT TISSUES FROM RADIATIONOCTET RULE: VALENCE SHELL MUST BE FILLED(8E-; OCTO)COMBINE OR SHARE E- TO BECOME STABLEINTERA-MOLECLUAR BONDS: (AKA CHEMICAL BONDS) BONDS THAT HOLD MOLECULES TOGETHER
ELECTROSTATIC ATTRACTION: AN ANION AND CATION ARE ATTRACTED TO EACH OTHER TO FORM A MOLECULE INTER-MOLECULAR BONDS: (PHYSICAL BONDS OR VAN DER WAALS FORCES) PHYSICAL BONDS THAT HOLD MOLECULES TOGETHERHYDROGEN SHELL: H2O MOLECULES FORM A COATING THAT REDICE ATTRACTION B/W POS & NEG SO THEY STAY IN SOLUTIONHYDROPHYLLIC: POLAR OR IONIC MOLECULES HAVE THE POTENTIAL TO DISSOLVE IN WATERHYDROPHOBIC: NON-POLAR MOLECULES NOT ATTRACTED TO WATER AND HAVE A LOW SOLUBILITY ACID: ABLE TO DONATE A PROTON TO A SOLUTION (H3O+)BASE: CAN INCREASE OH- CONCENTRATION OF SOLUTION &/OR ABSORB ACID(H3O+) FROM A SOLUTION
OXIDIZATION: REMOVES E- FROM AN ATOMREDUCTION: GAINS E- OXIDIZING AGENT: THE CHEMICAL THAT GAINS E-REDUCING AGENT: CHEMICAL THAT LOSE E-OXIDATION NUMBER: AVAILABLE E- FOR BONDING WITH OTHER ATOMS BUT CANNOT EXCEED THE VALUE OF VALENCE E-
VALENCE :NUMBER OF ELECTRONS THAT AN ATOM MUST GAIN OR LOSE TO BECOME STABLE
ELECTRON DOT DIAGRAM :SHOW VALENCE E- IN A MOLECULE & NOW THEY ARE SHARED
VALENCE & ELECTRON DOT DIAGRAM
Slide 5
CHEMICAL BONDING, ELECTRONEGATIVITY, MOLECULAR SHAPE
MOLECULAR TYPES OF BONDING: A)NON-POLAR COVALENT BONDS: TWO IDENTICAL BONDS SHARE E- EQUALLY TO BE STABLE (DIATOMICS-HOFBrINCl) B)POLAR-COVALENT BONDS: UNEQUAL SHARING OF E- BETWEEN TWO NON-IDENTICAL ATOMS(EX. H2O O IS NEG CAUSE IT IS PULLING THE H2 TOWARDS IT) C)IONIC BONDS: TWO NON-IDENTICAL ATOMS INTERACT AND ONE WILL FORCEFULLY TAKE THE E- THEY NEED CREATING A CATIONELECTRONEGATIVITY: THE TENDENCY FOR E- TO GAIN/LOSE E-. LARGER VALUES OF VALENCE TEND TO HAVE HIGHER ELECTRONEGAITIVIES
0-------------------------------------1.7-------------------------3.2 NON-POLAR COVALENT NEUTRAL PURE COVALENT
PURE COVALENT USUALLY B/W 0.3 & 2.9MOLECULAR SHAPE: IN ATOM WITH 4+ VALENCE E- THEY BEGIN TO PAIR UP THAT WONT FORM BONDS DIRECTLY, THESE TAKE UP MORE SPACE THAN TWO SINGLE E- & THEREFORE DETERMINES THE SHAPE WHICH DETERMINES THE BIOLOGICAL FUNCTION OF MOLECULESMOLECULAR POLARITY: POLARITY IS DETERMINED BY THE ELECTRONEGATIVITY OF BONDS AND THEIR ARRANGEMENT IN MOLECULE
Slide 6
PHYSICAL BONDING, CHEMICAL PROPERTIES OF WATER
THREE TYPES OF PHYSICAL BONDING:
LONDON FORCES: WEAK FORCES BETWEEN ALL ATOMS AND MOLECULES, ONLY FORM OF ATTRACTION B/W NON-POLAR MOLECULES
DIPOLE-DIPOLE BONDS: OCCURS IN ATTRACTION B/W POLAR OR IONIC MOLECULES, POSITIVE SIDE ATTRACTS WITH NEGATIVE SIDE (STRONGER THAN LONDON FORCES)
HYDROGEN BONDS: TYPE OF DIPOLE-DIPOLE BOND, FORMS B/W HYDROGEN & NITROGEN / OXYGEN / FLUORINE
WATER- SPECIAL MOLECULE: FUNCTIONS: SHOCK ABSORPTION, TEMPERATURE, REGULATION, LUBRICATION, DILUTION OF TOXINS, ETC...EXIST IN THREE STATES, POLAR MOLECULE, DENSITY OF SOLID H2O IS LESS THAN LIQUID H2O, AQUEOUS SOLUTIONS: WHEN A SOLUTE (EX. SALT) DISSOLVES IN SOLVENT (WATER) WATER IS A VERY EFFECTIVE SOLVENT
Slide 7
CHEMICAL RXTS: ACIDS AND BASES & BUFFERS
ACIDS & BASES: ACID: ALL ACIDS HAVE AN IONIZATION CONSTANT WHICH DESCRIBES HOW WELL THEY BREAK UP WHEN IN A SOLUTION. STRONGER ACIDS IONIZE COMPLETELY WHILE WEAKER ONES ONLY IONIZE PARTIALLY, THEY IONIZEBASE: THEY ABSORB AND INCREASE OH- CONCENTRATION 0-------------------7-------------------14ACID NEUTRAL BASEHUMAN BLOOD- B/W 7.2 & 7.4BUFFERS: PREVENTS RADICAL CHANGES IN PH BY ABSORBING EXCESS H+ AND OH- IONS IN THE SOLUTION, ESSENTIAL IN LIVING SYSTEMS, HUMANS HAVE 5 BUFFER SYSTEMS 1 IN KIDNEYS AND 4 IN YOUR BLOODTO MAKE A BUFFER- ACID (MOST COMMON ACID IN YOUR BLOOD CARBONIC ACID) + BASE (COMMON BASE IN YOUR BLOOD SODIUM HYDROGEN CARBONATE) = A BUFFER [H2CO3 -> H+ + HCO3- & NaHCO3 -> Na+ + HCO3- FORM THE EQUATION H2CO3 + NAHCO3 -> H+ + Na+ + 2HCO3]MEDICAL APPLICATIONS:
ACIDOSIS: TO MUCH ACID &/OR NOT ENOUGH BASE. SOME CAUSES ARE KIDNEY TROUBLE, CO2 RETENTION DUE TO LUNG TROUBLES (ASTHMA & PHEUMONIA). SYMPTOMS INCLUDE HEADACHE, BLUISH TINGE TO SKIN & LIPS, RAPID BREATHING, AND WEAKNESS
ALKALOSIS: TO MUCH BASE. CAUSES INCLUDE VOMITING EXCESSIVELYOR HYPERVENTILATING. SYMPTOMS INCLUDE DIZZINESS, CONFUSION & NAUSEA.
Slide 8
CHEMICAL RXTS P2: REDOX RXTS
OXIDIZATION: ATOM THAT LOSES E- IS SAID TO BE OXIDIZEDREDUCTION: ATOM THAT GAINS E- IS SAID TO BE REDUCED, TEND TO HAVE HIGH ELECTRONEGATIVITY VALUEOXIDIZING AGENT: REDUCED, HIGH ELECTRONEGATIVITY VALUEREDUCING AGENT: OXIDIZED, LOW ELECTRONEGATITIY VALUE DETERMINING OXIDATION NUMBER OF AN ATOM:TO DO THIS FOLLOW THESE RULES:
FOR ATOM IN ITS FREE STATE(BY ITSELF OR COMBINED WITH AN IDENTICAL ATOM) THE OXIDATION NUMBER IS ZERO.
OXIDATION NUMBER FOR MANY SIMPLE IONS ARE THE VALENCE E- NUMBER OF THAT ION
SOME NUMBERS ARE PERMANENTLY FIXED (EX. OXYGEN HAS THE NUMBER -2) BY THEM SELVES RULE 1 APPLIES
IN STABLE MOLECULES NUMBERS MUST ADD UP TO ZERO
SOME ELEMENTS HAVE MULTIPLE OXIDATION STATES
OIL: OXIDATION IS LOSING (POS CHARGED)RIG: REDUCTION IS GAINING (NEG CHARGED)
Slide 9
CHEMICAL RXTS P3: MAKING/BREAKING CHEMICAL BONDS- HYDROLYSIS AND DEHYDRATION SYNTHESIS RXTS
TWO MAIN TYPES OF THESE RXTS:
CONDENSATION RXTS: (DEHYDRATION SYNTHESIS) TWO SMALL MOLECULES FORM TO CREATE ONE LARGER ONE, ONE MOLECULE LOSES A HYDROGEN WHILE THE OTHER LOSES A HYDROXIDE WHICH FORM WATER.
HYDROLYSIS RXTS: ONE LARGER MOLECULE BREAKS DOWN INTO TWO OR MORE SMALLER ONES. (BACKWARDS TO CONDENSATION RXT).