Chemistry:Vishnu Kuriseti

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Bonding and Structure

Reactions

Periodic Trends

Stoichiometry

Electrons

Chem Basics

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Solutions

Kinetics

Thermochemistry

Equilibrium

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Advanced Chemical Ratios

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Avg Atomic Mass

Atomic numbers

Prop changes

Math Review

To smaller Unit->multiply

to Larger unit->divide

Metric(kilo hecto deka...)

Sig Figs

Dimensional Analysis

Dalton's Atomic theory

atoms have avg mass b/c of isotopes

nucleus

small

dense

postively charged

Atomic number=# protons

mass number=protons+neutrons

isotopes differ masses because of differing neutrons

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rewrite as fractions(conversion factors)

Cancel units top and bottom

Non-Significant

Significant

Leading zeros

Nonzero integers

Captive Zeros

trailing zeros(sometimes)

Multiplication-least number of sig figs

Addition/Subtraction-Least number of decimals

Extensive-mass,volume,energy

Intensive-melting and boiling point and density

Homogenous-composition is uniform

Heterogenous- varies from one region

physical change-alters state and appearance

chemical change- alters composition/identity

weighted avg

Avg atomic masses is avg of natural isotopes

% abundance(use to solve for avg mass)

Orbital Diagrams

Atomic Absorption

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Afbau-e- fill lowest possible energy level first

Pauli exclusion-no 2may have the same set of 4 quantum numbers

Hunds Rule-electrons fill fill each orbital before pairing

Noble gases have full valence shell

Use noble gases sort of as a short cut when writing configurations

Ions have a charge

cation lose e-

anion gain e-

Wavelengths can tell us energy gaps and transfer of e-

Emission-seeing wavelengths of energy released

Absorption-seeing missing bands of energy being absorbed

Ionic Radius

Atomic Radius

Ionization Energy

Electronegativity

Electron Affinity

Reactivity

1/2 distance between boded nuclei

increase down decrease to right

Zeff=Z-S

radius of ion

cation smaller anion bigger

energy required to remove e-

decrease down increase to right

Measure of ability an atom has to attract other e- of other compunds

decrease down increase right

HOw much energy released when atom get e-

decrease down and increase to the right

Metals increase down

non metals increase up

Bonds form to lower potential energy

Balancing

Types

Predicting Products

g=gas

s=solid

l=liquid

aq=aueous

Change coefficients to make sure the amount of reactants and products is the same

law of conservation

Synthesis- 2 thing into 1

Decomposition-1 thing into 2 things

Combustion-Burning(almost always has hydrocarbon)

Single Replacement-Swapping one element

Double replacement-Swapping 2 elements

Turn into formula

identify reaction

write products

Balance equation

Use Activity series and solubility chart to help predict products

Ionic Bonds

Transfer of e-

Metal+nonmetak

Between negative and positive charge

Covalent

Share electrons

NOnmetals+nometals

Metallic Bonds

Createse seas of e-

Only metals

Poly and Monoatomic Ions

Use periodic table to find charge for cation or anion

Neutral Compounds

Crossing OVer

Cancel out charges

Lowest possible combo to be neutral

Lewis Structture

Bonds occur with valence e-

octet rule-atoms want 8e-

Least electronegative goes in the center

Symmetry

bond=2e-

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AXE

A=central atom

X=#bonded atoms

E=lone electron pairs on central atom

Tells us about Electronic and Molecular geometry

Polar when electron not shared equally and non polar when shared equally

IMFs

Intramolecular Forces are inside and Intermolecular is between neighboring molecules

London Dispersion Force-Weak and temporary caused by unequal electron distribution(Everything has LDF)

Dipole-Dipole-Only in Polar Molecules and is when partially negative portion attracts to a partially positive portions

Hydrogen BOnding- Must have H and is strongest bond

Bulk Solids

Metallic(weakest)

Ionic Lattice(middle)

Network Covalent(strongest)

Use coefficients of the rxn for # moles of each chemical

Mole ratios Use them in dimensional anlysis

Percent yield=actual yield/Theoretical yield *100%

Avogadros Number = 6.02E23 objects(use for moles<->objects

Use molar mass for moles<->grams

Molar mass is grams per mole

Limiting Reagent-Reactant that is used up first in a rxn

If 2 starting values then its a limiting stoich problem

XS reactant- reactant you have left over of

Use dimensional analysis for Have vs Need

Percent comp= elements mass/molecules mass *100%

Empirical Formula- Reduced formula Ex:H6C6=HC

Ionic formulas always empirical and Covalent sometimes

Percent to mass

mass to moles

Divide by small

Multiply by whole

MOlecular Formula

Find mol. mass of empirical

divide by molecular formula by empirical formula mass

Multiply empirical formula subscripts by multiplier

Gas Laws

Absolute zero=0K

Boyle's law- P1V1=P2V2

Charles' Law- V1/T1=V2/T2

K=Celsius+273

Gay-Lussac's- P1/T1=P2/T2

Avogadro's Law- V1/n1=V2/n2

Combined Gas Law- P1V1/T1=P2V2/T2

Ideal Gas Law-PV=nRT(R is ideal gas constant)

Density= mass/volume

Use these equation to solve for unknowns

Specific heat is the amount of energy needed to raise the temp of 1 gram by 1 degree celsius

Specific Heat Units- J/g*degrees celsius

Q=MCdeltaT

C=specific heat

Q=energy lost/gained

m=mass

delta T=change of temp

+Q=endo

-Q=Exo

Calorimetry

Use 2 MCAT for each substance

1st law of thermodynamics is energy can't be created or destroyed

Q=-Q

Heating/Cooling curves

IF negative slope then cooling

IF positive slope then heating

Flat lines mean phase changes

MCAT for sloped lines and Q=ML for phase changes

Solute is the substance thats is being dissolved in asolution

Solvent is the substance that is being dissolved into

Solution is solute+solvent

Solubility is the amount of solute that can be dissolved at a certain temp

Saturated solution- max amount of solute dissolved

unsaturated solution is less than the max solute dissolved

super saturated solution is more than the max amount of solute dissolved

Colloids are when large particles are suspended in a substances

Dissociate- when ionic compound has its ionic bond disrupted by solvent molecules and breaks apart

Mass percent=mass of solute/mass of solution #100%

ppm=mass of solute/mass of solution *1,000,000

Grams per Liter=Mass of solute/Volume of solution

Mole Fraction=Xa=na/na+nb

M= moles of solute/Liter of solution

Dilutions M1V1=M2V2

Related to speed

Collision theory is that reactants have to collide to reacte

Activation energy is the min amount of energy required to react

factors of rxn rate

temp

concentration/pressure

surface area

Catalysts

doesn't get used up in rxn

Lowers AE

More effective collisions

Rate determining step is the slowest step

Can find rate by using the tangent line to a specific point on the graph

Rate Law K[A]^x[B]^y

x is the order for A and y is order for B

Order is the mathematical effect of an individual reactants concentration has on the overall rate

K is the rate constant

Rxns go forwards and back

Equilibrium is the point where the forward rxn occurs ta the same rate as the reverse rxn

Le chat's principle-if stress is applied to rxn @ equilibrium then the rxn changes to relieve the stress and finds new equilibrium point

Stresses

Temp change

Concentration change

Pressure/volume changes

Keq=[products]/[reactants]

USe partial pressure if no concentrations

k= q then @ equilibrium

k<Q then too many products

K>Q then too many reactants

ICE table= Initial, Change, Equilibrium

USe quadratic formula to solve for x and find the [] @ equilibrium

Can use the 5% rule if if K<1 and x is less than 5% of the initial []

Acid Bases

Bases

Acids

Bitter

Slippery

Commonly solids

Sour sharp taste

conduct electricity(are electrolytes)

React with metals

Arrhenius-Acids make H+ ions in aq solutions and bases make OH-

Bronsted-Lowry-Acids donate protons and Bases accept them

Lewis- Acids accept electron pairs and bases donate them

Arrhenius is most specific and Lewis is least specific

pOh is opposite of pH

pH measures power of hydronium ions

pH=-log[H+]

pOH=-log[OH-]

pH+pOH=14

Binary acid=hydrogen+highly electronegative element

Oxyacids are hydrogen +oxygen+a third element