Unit one Flashcards
What creates ionic bonds?
Electrostatic attraction between anion and cation
What creates covalent bonds?
Sharing electrons
What is electronegativity?
Measure of an atom’s attraction for the bonding electron it shares with another atom
What is the pauling scale trend?
Increases from left to right and bottom up
What electronegativity creates a nonpolar covalent bond?
Electronegativity differnece of .5 or less
What electronegativity creates a polar covalent bond?
Electronegativity difference of .5 to 1.9
What electronegativity creates an ionic bond?
Electronegativity difference greater than 1.9
What elements have the greatest polarity?
Top right corner
What creates bond dipoles?
Covalently bonded atoms with different electronegativites
What is the equaton for a dipole moment?
Charge times distance
What are the expections to the octet rule?
Elements in the third row can have less than 8 electron
What are the step for isomer generation?
Draw functional group, add needed atoms other than H, complete octet with H, then redo until there are no more variations possible
What is the molecular geometry and bond angle of an atom with four regions of electron density
Tetrahedral with 109.5 degree angles
What is the molecular geometry and bond angle of an atom with three regions of electron density
Trigonal pyramidal with 120 degree angles
What is the molecular geometry and bond angle of an atom with two regions of electron density
linear with 180 degree angles
What are the four things to finding the best resonance structure
most filled valence shells, most covalent bonds, how many bonds separate charges, and optimal charge distribution (- charges on high EN atoms and + charges and low EN atoms)
What are the rule of the molecular orbital theory
Number of atomic orbitals is equal to the number of molecular orbitals, molecular orbitals are arragned in order of increasing energy, and molecular orbitals are filled from lowest to highest energy
What is a sigma bond
Electron density lies between the nuclei and is made from single bonds and a direct overlap of orbitals
What is a pi bond
Electrons have higher energy than sigma bond electrons and are easily removed, result in repulsion of nuclei, and are made from double and triple bonds and parallel overlap of orbitals
What are antibonding molecular orbitals
electrons have higher energy and there is no electron density
What does bond length depend on
Valence shells (smaller shells (down), shorter bond # of bonds (more bonds, shorter length) Hybridization (more s chararacter, shorter bond) EN (more EN, shorter bond)
How do you tell if acid are more stable through charge?
If - and + charge are close, increase in stability but if like charges are close together, less stable
What are the 5 things to look at when determining if an acid is stronger?
Row periodicity (EN more to right, better) Hybridization (more s character, better) Column periodicity (acidity more down, better) Induction (atoms drawing charge towards itself) Resonance (more structures, better)
What is the lewis acid and base versus a bronsted acid and base
lewis acid accepts electrons while base donates. Bronsted acid donates H+ while base accepts H+
