Atomic Structure and Theories - Doc's Science Classes

Atomic Structure and Theories - Doc's Science Classes

Kinetics and Equilibrium Kinetics The study of the mechanisms of a reaction and the rates of reaction. Factors that effect Rate of Reaction (R of R) Collision Theory Anything that will increase the number of

and frequency of the collisions More effective collisions Factors that Effect Rates of Reactions (T,A,P,S,N,C) Temperature -(Average Kinetic Energy=motion) Inc. Temperature = Increase R of R Amount

Increase Amount (concentration) = Increase R of R Pressure (g only) - Inc Pressure = increase R of R Surface Area Inc. S.A. = Inc. R of R Nature of Reactants (Ionics > Covalents)

Due to their reactivity and the number of bonds needed to break Catalyst anything that is added that will increase the R of R If present will increase the R of R How? By providing an alternative pathway for the

Reaction by effecting 3 things 1. Ea of the Forward catalyzed Reaction 2. Ea of the Reverse Catlayzed Reaction 3. PE of the Activated complex Two Kinds

of Reactions Exothermic Endothermic Absorb Energy Heat + AB A +B Heat is a reactant Break Bonds + H

Release Energy A + B AB + Heat Heat is a product = Stability Bond formation H (Most Effective Collisions) Entropy

S Entropy is defined as the degree of randomness, disorder, chaos (s) (l) (aq) (g) Gibbs Free energy G

A reaction will always proceed spontaneously if the sign for Gibbs free energy is (-) The two conditions that favor a G are : low energy H Exothermic high entropy + S G

LeChateliers principle States that when a system that is at equilibrium is placed under a stress, the systems equilibrium will shift in order to relieve the stress Inc. (T) : will always favor endothermic reactions A+B

C+D Equilibriu m N2 3H2 NH3

HEAT X X X X

X X X X X X X

X X X X X CH4

3H2 CO2 H2 O HEAT X X X

X X X X X X x Acids and Bases

Acids Acids 1. 2. & Sour Taste Reacts with certain

metals on table J to yield H2(g) 3. Great Electrolytes (Why?) 4. Excellent Conductors of Electricity (Why?) 5. Cause Acid/Base Indicators to change colors

Bases Bases 1. Bitter 2. Slimy 3. Great Electrolytes (Why?) 4. Excellent conductors of Electricity (Why?) 5. Cause Acid/Base Indicators to change

colors Salt and Water to yield Acid reacts with Base Called the Neutralization Reaction The Neutralization Reaction Acid + Base -------------> Water HCl

+ NaOH --------> Salt NaCl

What kind of Reaction do you See? Double Replacement + + H 2O The Hydrolysis of a Salt The Reverse Reaction

Adding water to a salt! Water + Salt --------> Acid + Base H2O + NaCl -------------> NaOH HCl +

Called The Parent Acid and Base Definitions of Acid and Base Arrhenius Acid Any substance that yields (H+) as the only positive ion in solution HCl ------------> H+ +

ClHBr ------------> H+ + Br- H3O+ ----------> H + + HOH

Base Any Substance that yields (OH-) ion as the only (-) ion in solution (Recall: Goup I,II Metal with OH and NH4OH) NaOH --------> Na+ + OHCa(OH)2 -----> Ca+2 + 2OHNH4OH ----> NH4+ + OH- H3PO4 ---------> H+ H2PO4 - -------> H+ HPO4-2 --------> H+

+ Do not confuse Base with Alcoho HReminder: 2PO4 (Hydrocarbon-OH) + HPO4-2 CH3OH -3 CH OH

+ POCH 3 2 4 Amphoterism Any Substance That can act as either acid or base H3O+ ----------> H+ + HOH ------------> H+ + OHH3PO4 ---------> H+ + -------> H+ + HPO4-2

H2PO4- HOH H2PO4 - HPO4-2 --------> H+ + PO4 -3

Definitions of Acid and Base Bronsted - Lowery Acid Base Proton (H+) Donor Proton (H+) Acceptor H+

H+ H2O + H2O -------------> OH- + Strong Acid H3O+(SA) ----------> H + Weak Base (WB) + Weak Acid (WA) ------------> H+ + Strong Base (SB) Strong Acids and Strong Bases Strong Acids

HCl HBr HI H2SO4 HNO3 StrongBases Group I M Ca, Sr, Ba with OH pH Scale

pH Scale Is a scale that is used to measure if a substance is an acid or base Measures the Percent [H+] (The power of Hydrogen!) ****_____

pH Scale For every decrease in pH value, this represents a 10x Increase in [H+] 5 <---------- 6 <------------ 7 <----------- 8 10 x

10 x 10 x <------------------------------------------------------------1000 x pH Calculations Ksp (The ionization of H2O) H2O <-----------> H+aq + OH- aq

Keq = [H+] [OH-] Fact KH2O = 1 x 10 1 x 10-14 = [H+] [OH-] H+] = 1 x 10-7 [OH-] = 1x 10-7 Calculate pH pH = -log[H+] pOH = -log[OH-] pH = 7

pOH = 7 pH + pOH = 14 -14 pH calculations What are the pH values of the following? .1 M HCl .01 M HCl .001M HCl

The Hydrolysis of a Salt! Remember (it is the reverse reaction of a Neutralization __________________ reaction) KCl + HOH -----> KOH + HCl How can we determine the pH of the resulting solution?

Titration Def. A technique that is used to determine the strength of an unknown (acid or base) compared with a known (acid or base). (coef A) MAVA = MBVB (coef B) We need an acid base indicator:

Phenolphthalein Acid clear Pink Base Titration Technique Steps. Slowly add base to flask (watch for a color change to pale pink) ***Do not go past the end point!

(coef A) MAVA = MBVB (coef B) Titration Titration (coef B) A) MAVA = MBVB (coef

Titration and Calculations (coef A) MAVA = MBVB (coef B) End Point Naming Acids

This is Review! Binary (2 elements) Always starts with Hydro Name the Non-Metal (Chlorine) Drop the ending, add ic acid H2SO4 Hydrochloric Acid Hydrobromic Acid HNO3 Hydroiodic Acid

Tiernary (3 elements) M(PI) ate ic Sulfuric iteAcid - HNO ous2 Nitric Acid H SO

2 3 M(PI) Sulfurous Acid Nitrous Acid Redox and electrochemistry Assigning oxidation numbers

1. Metals in group 1 have (+1) ox #, group 2 metals (+2) 2. Any single Pure element = 0 3. Hydrogen is always (+1) except in metal hydride (-1) LiH 4. Oxygen is always (-2) exceptions: With flourine (flouide) +2 OF2 In Peroxides (-1) H2O2

5. The sum of all oxidation #s must = 0 6. The sum of all Polyatomic ions must equal the charge of that ion Assigning oxidation numbers Binary Compounds _____ HCl _______ MgCl

1. Start with the Non Metal 2. Finish with the Metal 3. Sum up must = 0 Assigning oxidation numbers Ternary Compounds _____ H2SO4

__________ Mg(NO3)2 1. Start with the Non Metal (Oxygen) 2. Go to the Metal (H) 3. finish up in the middle 4. Sum up must = 0 Redox Reactions (reactions where both Oxidation and Reduction take place)

1. Oxidation Reduction Loss of Electrons The gain of Electrons Half Reactions

Mg0 Mg+2 + 2e(product) Half Reaction 2e- + Mg+2 Mg0 (reactant) LEO SAYS GER OIL RIG Causes the Reduction of the

other elements Causes the other species to be Oxidized. Acts as a REDUCING AGENT (R.A.) Acts as the Oxidation Agent (O.A.)

Writing half reactions determine the Ox / red ra / oa Steps (Now this is Docs Method! ..Capisco?) 1. Assign the Ox #s 2. Record the changes 3. Record e- loss / e- gain 4. Determine the species that is oxidized (RA) and reduced (OA) 5. Balance if unequal Ca + Cl2

CaCl2 ***HHH___ All Redox Reactions must demonstrate conservation of both Mass and Charge Electrochemical cell Spontaneous cell (battery) Voltaic cell, galvanic cell Al

Cu (****Chemical energy electrical ****)A RED CAT IS AN OX Remember: TABLE J and.A RED CAT GETS FAT!!!!!! Electrochemical cell Spontaneous cell (battery)

Voltaic cell, galvanic cell Electrochemical cell Spontaneous cell (battery) Voltaic cell galvanic cell Electrochemical cell Spontaneous cell (battery) Voltaic cell galvanic cell

Electrochemical cell Spontaneous cell (battery) Voltaic cell, galvanic cell Electrolytic cell non-spontaneous cell (need a power source) electroplating electrolysis (****electrical chemical energy****)

Electrolytic cell non-spontaneous cell (need a power source) electroplating electrolysis (****electrical chemical energy****) Electrolytic cell non-spontaneous cell (need a power source) electroplating electrolysis of water!!!

Electrolytic cell non-spontaneous cell (need a power source) electroplating electrolysis of water!!! Electrolytic cell non-spontaneous cell (need a power source) electrolysis of water!!! 2H2O 2H2 + O2

Organic chemistry Hydrocarbon series Alkanes All end in -ane General formula CnH2n+2 Identify by the C-C bone (single) Saturated Hydrocarbons

Alkenes All end in ene General Formula CnH2n See C=C double bond Hydrocarbon series Alkynes

All end with yne General Formula of CnH2n-2 Identify the triple bond Hydrocarbon series Cyclic Hydrocarbons Also called Aromatic Hydrocarbons Also called Benzene series

General formula is CnH2n-6 Benzene C6H6 Hydrocarbon series Cyclic Hydrocarbons Toluene C7H8 Also called Methyl Benzene

Naming hydrocarbons Steps 1. Identify the longest C-C continuous chain Naming hydrocarbons Steps 2. Look for any C=C or C=C Bonds and identify by the lowest Carbon number location

Naming hydrocarbons Naming hydrocarbons Naming hydrocarbons Step 3. Look for any Alkyl side chains: (Alkyl groups are Alkanes less 1 Hydrogen) Alkane Alkyl

Dienes contain 2 double bonds Functional Group - replaces a H atom of a hydrocarbon - an atom (or group of atoms) that give an organic compound specific chemical and physical properties (the following slides discuss functional groups for reference, I will show you how to correlate with your reference table O) R = an atom or group of atoms

in a Hydrocarbon chain Organic Halides (Halocarbons) X = a Halogen (Group 17) RNaming Rule Indicate position X of halogen on

longest hydrocarbon chain. Alcohols R-OH Naming Rule Indicate position of -OH group on carbon chain. Change e of alkane name to ol.

Ethers ROR Naming Rule Name each R group and tack-on ether. Aldehydes and Ketones Naming Rules Aldehydes: Change e of alkane name to al

Ketones: Indicate position of carbonyl Change e of alkane to one Organic Acids Naming Rules Change alkane e to oic acid Organic Acids Esters

O R C O R Naming Rules 1. Name R alcohol group 2. Change R alkane e to oate ***HHH______ Made from combining an Acid and an Alcohol Esters

Amines R R N R Naming Rules Label position of N. Change e of alkane name to amine. AMINO ACIDS

Amides O R RCNH Naming Rule Change e of R alkane name to amide

Types of organic reactions 1. HALIDE ADDITION REACTIONS Adding a halogen to an unsaturated hydrocarbon (alkene / alkyne) Yields 1 product! + Br2 Types of organic reactions 1. HALIDE SUBSTITUTION REACTIONS

Adding a halogen to a saturated hydrocarbon (alkane) Yields 2 products, one an acid! + Br2 Br + HBr

FERMENTATION A reaction that always yields Ethanol and CO2! Recall: anaerobic Respiration?? COMBUSTION A burn reaction (always needs O2) and always yields CO2 and H2O SAPONIFICATION Making of Soap, always yields an

Alcohol (Glycerol) and Soap! SAPONIFICATION Look for the 3 NaOH bases!!!! ESTERIFIACTION Making Esters Acid + Alcohol yields an Ester and Water +

C C ethanol + H2O ESTERIFIACTION Making Esters

Acid + Alcohol yields an Ester and Water ESTERIFIACTION Note the Esters 1. fragrances, sweet smells (bananas) ESTERIFIACTION Naming revisit 1. Start with the Alcohol Side 2. Finish with the Acid side

POLYMERIZATION The making of polymers 1. Natural proteins, polysaccharides 2. Artificial plastics, nylons, rayon Addition Polymerization POLYMERIZATION Addition Polymerization

Nuclear Chemistry Fact! 1. A Transmutation is any alteration in the nucleus 2. There are no stable isotopes above element #83 1. Elements that are unstable will emit energy in the form of

Radiation 2. Called Radioisotopes 3. Stability is based on the P:N Ratio Types of Particles that are Emitted Particle Type Symbol Mass

Charge Penetrati ng Power He4 4

2 Low e0 , - 0 -1 Modera

te e0 , + 0 +1 Modera te

0 0 0 0 High X-ray

Alpha 2 Beta -1 Positro n

Gamma +1 The Effects of an Electric field on Charged Particles 2 Types of transmutations 1. Natural A type of Decay that occurs naturally

therefore you will see only 1 reacting nuclei that will undergo a change 1. Alpha ( )Decay 2. Beta ( )Decay 3. Positron ( ) emission 4. Gamma ( ) decay

Artificial A type of Decay that does not occur naturally, therefore you will see 2 nuclei reacting 2 Types 1. Fusion 2. Fission Natural Decay and Writing Nuclear Equations Alpha

Notice several things about it: 1) The atom on the left side is the one that splits into two pieces. 2) One of the two atoms on the right is ALWAYS an alpha particle. 3) The other atom on the right ALWAYS goes down by two in the atomic number and four in the mass number. More Examples of Alpha decay More Examples of Alpha decay

Check it and compare the three points to the example. Keep in mind that this equation shows the left-hand side splitting into the two pieces shown on the right-hand side. OK, write the alpha decay equations for these five nuclides. Beta decay and writing equations Beta decay practice Here's your first set of exercises. Write out the full beta decay equation. Then click the link to see the answers.

Beta decay practice Here's your first set of exercises. Write out the full beta decay equation. Then click the link to see the answers. Positron emission B+, +1e0 37 K ------> 19

0 e + +1 37 Ar 18 Pet scan (positron emission)

Gamma decay No change in Mass or Charge Artificial Decay The conversion of matter into energy Fusion Fission

A reaction where 2 lite The splitting of nuclei (alike) are joined together to make a heavier nuclei. Ex: Reactions on the Sun Good: Yields A lot of Energy Bad: Requires a lot of

energy to run Fuse 2 like nuclei (repel) Need particle accelerators to inc. KE heavy nuclei (bombard with high energy Neutrons 0N1) into a smaller nuclei Good: Yields a lot of energy

Bad: Produces a lot of Radioactive waste (disposal issues and half life) Synchroton Cyclotron Fusion H1 + 1H1 -----> 1H2 + +1e0 + energy 1 + H2 ------->

3 1H 1 2He 1 Fission 0 n1 + 92U235 ------> ENERGY

56 Ba142 + 36 n1 + 92U235 ------> ENERGY 54

Xe143 + 38 0 Kr91 + 3 0n1 + Sr90 + 3 0n1 +

Half-life The time that it takes for a substance (radioactive) to lose its mass. A. Determine the Age of rocks (Carbon Dating) During Half-Life Problems Remember: 1. the longer the half-life, the SLOWER the decay (Dangerous) 2. The shorter the half-life, the faster

the decay (used in medicine) Calculating the half-life You will need to know 5 things 1.Total time 2. life time 3.# of half life 4.Initial Mass 5.Final Mass

If asked what fraction remains? Always start with # of

(1) Half lifes If starting with Initial Mass # of Half lifes 128g 64g 32g X

16g 8g 4g 2g 1g 1

1 2 3 4 5 6 7 X

1/2 1/4 1/8 1/16 1 2 3 4

Half-Life Initial Mass = Total Time # of life time lifes 2

# 2 Final Mass 1)The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed? 12.5g remaining 2)Os-182 has a half-life of 21.5 hours. How

many grams of a 10.0 gram sample would have decayed after exactly three halflives? 8.75g decayed, 1.25g remain 3) At time zero, there are 10.0 grams of W187. If the half-life is 23.9 hours, how much will be present at the end of one day? Two days? Seven days? 1 day = 5.00g, 2 days = 2.50g, 7 days = .078g Uses of radioisotopes

Carbon Dating C14 no longer taken in by a dead organism Ratio of U238/Pb206 to date rocks I131 used to study thyroid conditions Co60 emits large amounts of gamma radiation. Used in treating cancers like Prostate Co60 and Cs137 emit gamma rays, used to kill Anthrax Bacilli Tc43 used to treat cancerous tumors, absorbed by cancer cells

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