Organic Chemistry

Properties of Organic Compounds

• Must contain carbon
• Covalent bonds
• Most are non-polar
• Low melting point / boiling point
• Non-electrolytes (organic acids are an exception)
• Undergo combustion with oxygen 
• Decompose at low temperatures
• Slow rate of reaction

Alkanes: all single bonded carbons (saturated)
Alkenes: one double bond between carbons (unsaturated)
Alkynes: one triple bond between carbons (unsaturated)

Isomers: same molecular formula, different structure

Reference Table

• Organic Prefixes - Table P
• Homologous Series of Hydrocarbons - Table Q
• Organic Functional Groups - Table R

Organic Reaction Flashcards
Organic Chemistry Regents Questions

Redox & Electrochemistry

Oxidation: loss of electrons
Reduction: gain of electrons

Oxidizing Agent: substance reduced
Reducing Agent: substance oxidized

Anode: electrode where oxidation occurs (AN OX)
Cathode: electrode where reduction occurs (RED CAT)

Salt Bridge: allows the flow of ions between the anode and cathode solutions to keep a balance of charge

• Cations flow toward the Cathode
• Anions flow toward the Anode

Single replacement reactions are always Redox – Table J is used to predict  which metal will replace another. More active free metal will replace less active metal in a compound.

Double replacements never are Redox. 

Electrochemical Cells (Voltaic Cells)

• Batteries
• Spontaneous redox reaction
• Generates Electric Current
• Positive Voltage
• Anode is NEGATIVE
• Cathode is POSITIVE
• Cathode gains weight
• Electrons move from Anode --> Cathode

Electrolytic Cells

• Non-spontaneous redox reaction
• Electricity must be used for reaction to occur
• Negative Voltage
• Used to obtain pure elements from aqueous ions
• Anode is POSITIVE
• Cathode is NEGATIVE
• Electrons move from Cathode --> Anode

Redox Flashcards
Redox Electrochemistry Regents Questions

Acids, Bases, & Salts

Base pH > 7 [H+] < [OH-]
Acid pH < 7 [H+] > [OH-]
Neutral pH = 7 [H+] = [OH-]
pH + pOH = 14

A decrease of 1 pH unit represents a tenfold increase in the hydronium ion concentration
An increase of 1 pH unit represents a tenfold increase in the hydroxide ion concentration


The Arrhenius Definition
Acid: a substance that when dissolved in water increases the concentration of hydrogen ion, H⁺
Base: a substance that when added to water increases the concentration of hydroxide ion, OH<sup>-

ACIDS AND BASES ARE ELECTROLYTES</sup>
An electrolyte is a substance that, when dissolved in water, forms a solution capable of conducting an electric current

Neutralization Reaction
Acid + Base --> Salt + Water

Acids react with metals to form H2 gas
Be familiar with the common acids and bases found on Table L & K
Use Table M to determine what color acids and bases turn indicators

Bronsted-Lowry Theory of Acids and Bases
Acid- proton (H+) donor
Base- proton (H+) acceptor

Titration: A laboratory procedure in which a volume of solution of known concentration is used to determine the concentration of another solution
MAVA = MBVB

Acid Base Regents Questions

Kinetics & Equilibrium

Equilibrium
Rate of forward reaction equals the rate of the reverse reaction
Concentrations are constant not equal

Collision Theory
A reaction is most likely to occur if reactant articles collide with proper energy and orientation

The Rate of a Chemical Reaction Depends on

• Temperature (increase temperature increases rate)
• Concentration (increase concentration increases rate)
• Surface Area ( increase surface area increases rate)
• Presence of Catalyst (increases rate)

Le Chatelier's Principle
Equilibrium systems will shift to relieve stress

• Temperature change: The addition of heat to an exothermic reaction will shift the equilibrium towards the reactants. The addition of heat to an endothermic reaction will shift the equilibrium towards the products
• Concentration change (gases and aqueous solutions only): Equilibrium will shift toward the side with lower concentration  Ex. the addition of product or the removal of reactants will shift the equilibrium towards the reactants
• Pressure change (gases only): If pressure increases or volume decreases the equilibrium will shift toward the side with fewer moles of gas. If pressure decreases or volume increases the equilibrium will shift toward the side with greater moles of gas
• Effect of catalyst: lowers the activation energy but does not effect the equilibrium (provides an alternative reaction pathway)

Entropy: Measure of randomness or disorder
Systems in nature tend to undergo changes toward lower energy and higher entropy

Table I - Heats of Reaction: Negative values are exothermic. Values are given for the number of moles (coefficients) shown in the equation.

Potential Energy Diagrams

Energy released or absorbed by a chemical reaction (heat of reaction) is equal to the difference between the potential energy of the products and the potential energy of the reactants

Kinetics/Equilibrium Regents Questions

Nuclear Chemistry

Types of radioactive emissions

Particle charge and mass given in Table O
Particles with a higher mass have lower penetration power. Alpha is least, gamma is greatest. 
The energy released during nuclear reactions is much greater than the energy released during chemical reactions
Nuclear reactions lose some mass due to conversion of mass to energy

Transmutations – change from one element to another 
Natural Transmutation: Spontaneous radioactive decay. Only one reactant. 
Artificial Transmutation: Bombardment of element with high E particle. Two reactants.



Half Life Problems: Half lives are constant. Every X amount of time the mass will halve.
Use Table N to find a nuclide's half-life and decay mode.

Fission Reactions
A nuclear reaction in which the nucleus of an atom splits up into lighter nuclei with the simultaneous release of energy
Nuclear Bombs- Uncontrolled chain reactions
Nuclear Power Plants- Controlled chain reactions

Fusion Reactions
A nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy
Produces more energy than fission
Needs extremely high temperatures- occurs on the sun

Uses of Radioactive Isotopes
I-131: diagnosing and treating thyroid disorders
C-14 & C-12: dating living organisms
Co-60: treating cancer

Nuclear Regents Questions

Gases

Kinetic Molecular Theory for Ideal Gases

1. Gases consist of small particles
2. Particles are in constant, random, straight-line motion
3. The molecules in a gas occupy no volume
4. Collisions between molecules are perfectly elastic
5. The average kinetic energy of gas particles depends on temperature

Gases behave most ideally at low pressure and high temperature
The most ideal gases are hydrogen and helium

Combined Gas Law: PV/T = PV/T

Pressure and volume are inversely related

Pressure and temperature & volume and temperature are directly related

Temperature must be in Kelvin to do calculations

Avogadro's Hypothesis: Equal volumes of gas at the same temperature and pressure have the same number of particles

Dalton's Law of Partial Pressure: The total pressure is equal to the sum of the individual pressures

Graham's Law of Diffusion: Lighter gases diffuse at a faster rate

Table H
Vapor pressure increases as temperature increases

Vapor pressure increases as the forces of attraction between molecules decrease

Boiling point: when atmospheric pressure = vapor pressure

Gas Regents Questions

Moles & Stoichiometry

A compound is a substance composed of two or more different elements that are chemically combined in a fixed proportion
Types of chemical formulas include empirical, molecular, and structural
The empirical formula of a compound is the simplest whole-number ratio of atoms of the elements in a compound
It many be different from the molecular formula, which is the actual ratio of atoms in a molecule of that compound
In all chemical reactions there is a conservation of mass, energy, and charge
The molar mass (gram formula mass) of a substance equals one mole of that substance
The percent composition by mass of each element in a compound can be calculated using these gram formula masses

Moles
1 mole = gram formula mass
1 mole = 6.02x10^23 particles
1 mole = 22.4L of any gas at STP

Types of Equations

Combustion: A combustion reaction is when oxygen combines with another compound to form water and carbon dioxide. These reactions are exothermic. 
C₁₀H₈ + 12 O₂ ---> 10 CO₂ + 4 H₂O

Synthesis: When two or more simple compounds combine to form a more complicated one. These reactions come in the general form of: A + B ---> AB

Decomposition: A complex molecule breaks down to make simpler ones. AB ---> A + B

Single replacement: When one element trades places with another element in a compound. 
A + BC ---> AC + B

Double replacement: When the anions and cations of two different molecules switch places, forming two entirely different compounds. AB + CD ---> AD + CB
Identify the precipitate using Table F

Moles Regents Questions

Combining Matter & Physical Changes

Combining Matter Physically
Heterogeneous Mixture: Does not have a definite composition, non-uniform
Homogeneous Mixture: Uniform throughout 
Ways to separate mixtures:

• Filtration
• Distillation
• Evaporation
• Chromatography
• Crystallization

Dissolving and Solution Formation

• Solutions are Homogeneous Mixtures
• The concentration of a solution may be expressed as: molarity, percent by volume, percent by mass, or parts per million- Table T
• An increase in temperature, stirring, and surface area increases the rate of dissolving
• Polars dissolve in polar solvents
• Non-polars dissolve in non-polar solvents
• Solids dissolve best at high temperatures
• Gases dissolve best at high pressure and low temperatures
• Solutions have lower freezing points and higher boiling points than pure substances
• Ionic compounds form ions in solution and are electrolytes -conducts electricity when dissolved in water
• Use Table F to determine if a compound is soluble

Using the Solubility Curves (Table G)
Predict solubility at different temperatures
How much more solute can you add if the temperature changes
How much solute will precipitate out if the temperature changes

Saturated solution- a solution in which the maximum amount of solute has dissolved in the solvent at a given temperature
Unsaturated solution- a solution in which the solute has completely dissolved in the solvent
Supersaturated solution- a solution in which the amount of solute dissolved under given conditions exceeds its supposed upper limit

Properties of Matter

Physical Properties: Can be observed without changing identity (Density, color, conductivity)

Chemical Properties: Can be observed when matter is reacting (Flammability, heat of combustion)

Physical Change: Formula does not change (Boiling, melting, dissolving)

Chemical Change: Reaction occurs, new products (Rusting, burning)

A pure substance, such as an element, has a constant composition and has constant properties throughout a given sample and from sample to sample.

Elements cannot be broken down by chemical change.

Chemical Changes and Solutions Regents Questions

Energy & Phase Changes

Energy

Law of Conservation of Energy
Heat : Involves transfer of energy
           Flows from high temperature to low temperature
           Describe changes to the motion of particles when heat added or taken away
Temperature:  measure of average kinetic energy
Kelvin = Celsius + 273
Absolute zero = 0 Kelvin

Endothermic Reaction: Needs heat to occur

Exothermic Reaction: Produces heat

Intermolecular Forces - Bonds between molecules
    Forces must be overcome to change phase

Dipole-Dipole

• Between polar covalent molecules

Hydrogen bonding

• Between polar molecules where hydrogen is bonded to a very E.N. atom (F, O, N)
• Strongest intermolecular force
• Creates higher melting and boiling point

Van der Waals forces

• Attraction between non-polar molecules
• Weakest attractive force
• Only felt when molecules are close together
• Substances have lowest MP/BP
• Strongest when there are more electrons in the molecule

Matter
Three Phases of Matter and Their Properties: Solids, Liquids Gases
Phase Changes: Melting (fusion), Vaporization, Condensation, Freezing, Sublimation, and Deposition

Heating & Cooling Curves (Change of Phase Diagrams)

Kinetic Energy does not change during phase changes
KE increases when temperature increases
PE changes during a phase change

The Heat Equations
Measuring Heat Energy when Temperature Changes
Q=mc /\ T
Measuring Heat Energy During Phase Changes
Q=mHv        Q=mHf

Energy and Phase Change Regents Questions

Compounds: Bonding Between Atoms

Bond Formation
-stable octet formed (except H and He which can only hold a max of 2 electrons)
-results in lower energy state for atoms
Energy is released when bonds are formed

Metallic Bonding
Positive metal cations in a sea of mobile e-
Prop. of metals caused by this type of bonding

Ionic Bonding
Metal + Nonmetal
Prediction Ionic Compound formulas
     criss-cross the charges
     compound must be neutral
Emprical Formulas:
     simplest whole # ration of atoms or ions
Using Polyatomic ion chart (table E)
Naming Ionic Compounds
     - Stock System
     - Binary compounds
     - Ternary Compounds (with polyatomic ion)
     - Use Roman Numerals if nmetal has more than one possible positive charge
Properties of Ionic Compounds
Lewis Dot Diagram of Ions & Ionic Compounds

Covalent Bonds
Two or more nonmetals
Types of bonds:
Polar Covalent Bond: Atoms have different electronegativity
Non-polar Covalent Bond: Atoms have the same electronegativity
Coordinate Covalent Bond: One atom gives 2 electrons to a shared pair in bond, other atom gives none
Network Bond: Very strong bond, highest melting point, found in macromolecules (like diamonds) highest
                         MP
Molecular Formulas: show actual # of each atom
Structural Formulas: show bonding between atoms
Naming Molecular Compounds
     - prefix system to show how many of each element is present
     - use of Stock system with Roman Numerals, first nonmetal in formula takes + charge
Properties of Covalent Compounds
Lewis Dot Diagram of Molecules & Polyatomic Ions

Polarity & Molecules
Determine if bonds are polar or non-polar (look at electronegativity differences)
Determine if molecule is polar or non-polar (look for polarity of bonds, shape and symetry)
Shapes of Molecule: (linear, bent, tetrahedral, and pyramidal)

To determine if a bond is polar or non-polar look at electronegativity differences

To determine if a molecule is polar or non-polar look at shape, symmetry, and the polarity of bonds
Shapes of Molecule: Linear, bent, tetrahedral, and pyramidal.

Atomic Structure & The Periodic Table

Atomic Structure

• Protons 1 amu positive charge found in nucleus
• Neutrons 1 amu neutral charge found in nucleus
• Electrons  Mass close to zero negative charge found in clouds surrounding nucleus
• The nucleus is positively charged

determining the # of p n and e in a neutral of charged ion
isotopes
calculating average atomic mass

Theories of Atomic Structure
dalton Thompson
Rutherford's Gold Foil Experiment- an atom is mostly empty space with a dense, positively charged nucleus
bohr's energy levels
higher energy e- farther from nuclus
Spectral Lines- formed when excited electrons release energy and fall back down to ground state
quantum theory
principle energy levels
Hunds rule for orbital filling
excited vs ground state configurations
determining number of valence electrons

Periodic Table
groups/families- how are elements alike
names of important groups
periods- what do these elements have in common
solid liquids and gases
metals lose electrons and form positive ions
nonmentals gain electrons and form negative ions
properties
metalloids
metallic character nonmetallic character
most reactive metals
most reactive nonmetals
atomic vs ionic radius
trends
Atomic Regents Questions