×
Log in to StudySoup
Get Full Access to Clemson - CH 2010 - Study Guide - Midterm
Join StudySoup for FREE
Get Full Access to Clemson - CH 2010 - Study Guide - Midterm

Already have an account? Login here
×
Reset your password

CLEMSON / Chemistry / CH 2010 / What happens when atoms share electrons equally?

What happens when atoms share electrons equally?

What happens when atoms share electrons equally?

Description

School: Clemson University
Department: Chemistry
Course: Survey of Organic Chemistry
Professor: Thomas hickman
Term: Fall 2016
Tags: CH, 2010, and Organic Chemistry
Cost: 50
Name: CH 2010 Exam 1 Study Guide
Description: This study guide covers the all the material on exam one.
Uploaded: 09/07/2016
5 Pages 54 Views 3 Unlocks
Reviews


CH 2020 Exam 1 Study Guide


What happens when atoms share electrons equally?



Chapter 1 Bonding and Isomerism

- Bonding Patterns

o Hydrogen likes to form 1 bond.

o Oxygen like to form 2 bonds.

o Nitrogen likes to form 3 bonds.

o Carbon likes to form 4 bonds.  

o Halogens like to form 1 bond.

- Be able to draw Lewis Dot Structures (LDS) for all types of molecules o Make sure the octet rule is followed for every atom

o Make sure the total number of valence electrons in the LDS add up to  the number of electrons you calculated

o DON’T FORGET LONE PAIRS

- Formal Charge (FC)  

o The charge an atom appears to have when considering that all bonding electrons ae shared equally  

o To calculate formal charge, take the number of valence electrons from  the periodic table and subtract the number of electrons surrounding  the atom.  


How do you know which resonance structure is best?



Resonance Structures and Multiple Bonds

- Electronegativity is an atoms willingness to adopt an electron.  o It increases up and to the right

o Fluorine is the most electronegative atom

- Bond-Line Formulas (Skeletal/Polygon)

o Shows carbon Skelton

o Lines are drawn in a zigzag format so every end intersection  represents a carbon

o Omit the H atoms

o Include functional groups

o REMEMBER EACH CARBON GETS 4 BONDS

- Drawing Resonance structures

o Arrows are used to show electron involvement

 Move electrons toward the positive charge and away from the  negative charge

 Only pi electrons or lone pair electrons (not sigma electrons or  atoms) may be shifted only to adjacent atoms or bond positions ∙ From pi bond to adjacent bond


Why do carboxylic acids smell bad?



If you want to learn more check out What is a plant cell without a cell wall?

∙ From pi bond to adjacent atom

∙ From an atom (lone pair) to an adjacent bond

 Resonance structures in which an atom carries more than its  quota of electrons (8 for C, N, O, F) are NOT contributors to the  real structure.

 The more important RS (Resonance Structure) (major vs. minor)  show each atom with a complete octet and as little charge  

separation as possible. Don't forget about the age old question of What are our closest living relatives?

Functional Groups

o Be able to identify and name functional groups

Acids and Bases

o Bronsted-Lowry Theory

 Strong bases produce weak acids

 Strong acids produce weak bases

o Strong and Weak acids and bases

 Strong acids undergo complete dissociation

 Weak acids undergo partial dissociation  

o Bases

 Classified as strong or weak based on their affinity for H+

o Amines

 Similar to ammonia

 Weak bases

 Undergo reversible reactions

 A strong acid can drive it to completion  

o Carboxylic Acids

 Weak acids Don't forget about the age old question of How do you illustrate vectors?

 Can be driven to completion by a strong base

o pH and pKa  

 the lower the pKa the more acidic

o Organic Acids and Bases

 Carboxylic Acids  

∙ pKa values from 4-5

 Alcohols

∙ pKa values from 15-19

 Amines

∙ pKa values from 35-40

 Protonated Nitrogen

∙ pKa values around 10

 Protonated Oxygen If you want to learn more check out What is the function of the simple columnar epithelium?

∙ pKa values around -2

Equilibrium

o REMEMBER: when drawing arrows to show how the products of a  reaction are formed, they always go from ELECTRONS TO THE H and  then from the BOND TO THE ATOM

o The reaction is always favored from the Strong Acid to the Weak Acid o Acidity increases as pKa decreases

Factors Affecting Acidity (ARIO)

o Atom If you want to learn more check out What are passive leg exercises?

 Size: the larger atom disperses the negative charge over a  larger region

 Electronegativity: the more electronegative atom can carry the  negative more readily

o Resonance

 If the conjugate base of an acid is able to move the negative  charge to other atoms it is more stable, making the acid more  acidic

o Inductive effect

 Election withdrawing groups (EWG) can disperse the negative  charge, making the compound more acidic

 The closer an electronegative atom is to the negative sign the  more acidic the compound

o Orbital (Hybridization)

 The less electron domains the more acidic

 The less p’s in the hybridization the more acidic

Acid-Base properties of amino acids

o If the pH of a solution is less than pKa, the proton is ON

o If the pH of a solution is greater than the pKa, the proton is OFF o Electrophoresis: separation of amino acids

Chapter 2 Alkanes

Structural Isomers

- Compounds with the same molecular formula and different connectivity - Longer chains have more contact with each other, which gives them a higher  boiling point  Don't forget about the age old question of What were some of the characteristics of paleolithic society?

Alkanes and Cycloalkanes

- Compounds with no double bonds are called saturated hydrocarbons - Compounds with double bonds are called saturated hydrocarbons - All have the –ane ending  

- “cyclo” means ring

- Naming alkanes:

o Count the number of carbons on the longest chain

 This gives you the pre fix you need to go with –ane

 If the molecule contains a double bond it has to be counted as  part of the longest chain  

o Give the any remaining substituents a name based on the table below  and describe their place

o Remember to separate numbers with commas and letters from  numbers with a hyphen

Physical Properties

- The longer the chain (more contact area) the higher the boiling point  o The more compact a molecule is the harder it is for the molecules to  connect, making it easier to break them apart, resulting in a lower  boiling point  

o Oxygen forms stronger H-bonds than Nitrogen

Reactions of Alkanes

- Two primary reactions  

o Combustion  

 oxidation

o Halogenation

 In the presence of uv light, the reactants produce a free radical  Free radical mechanism

∙ Arrows must be drawn with 1 barb

∙ 3 stages:

o Initiation

o Propagation

 Becomes a cycle

o Termination:

 Coupling  

∙ Free radicals can do 3 things:

o Couple  

o Abstract H-atoms

o Add to a double bond  

∙ Free Radical Stability  

o Treat radicals like C+ atoms

Page Expired
5off
It looks like your free minutes have expired! Lucky for you we have all the content you need, just sign up here