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Convert the following condensed structures to lewis structures:
CH3Br CH3OH CH3OCH3 (CH3)3COH CH3NH2
(#s are subscripts)
answer in session
List the number of sigma & pi bonds in the following:
Single bonds, Double bonds, Triple bonds
List the number of sigma & pi bonds in the following:
Single bonds - 1 sigma
Double bonds - 1 sigma, 1 pi
Triple bonds - 1 sigma, 2 pi
What must a lewis acid contain in order to act as an acid?
Empty orbital
The concentration of __ is used to measure acidity. This is called pH.
The concentration of _H+__ is used to measure acidity. This is called pH.
What 5 factors affect pKA values? Explain how.
Size, Hybridization, EN, Resonance, Substituents
T/F: it is possible to draw out 3 CH3s in a row.
False!
Why are sigma bonds generally stronger than pi bonds?
They're head on bonds; they also contain S orbitals which ten to pull e- closer to the nucleus
Which 2 atoms violate the octet rule and are therefore considered a lewis acid?
Al and B
T/F: pH is a reliable measurement for how strong or weak an acid is.
False!
Define resonance.
Movement of delocalized electrons, resulting in different lewis structures of the same molecule.
What orbitals overlap to form the sigma and pi bonds in the molecule C₂H₄ (ethene)?
Sp2 -S , P-P
Define an acid. How does it differ from a base?
Acid = gives away its proton in a reaction (becomes more -) base = accepts proton in reaction
Define a conjugate acid and a conjugate base.
Conjugate acid pairs with the base ( more positive +1H) Conjugate base is the acid after the reaction (more negative -1H)
Fill in the blank as a strong or weak
Ka>1 = ___ acid Ka<1 = _____ acid
Ka>1 = ___weak___ acid
Ka<1 = ___strong___ acid
If we are comparing atoms in the same column.. Which factor that affects pka do we use?
If we are comparing atoms in the same row.. Which factor that affects pka do we use?
Size
EN
Define hybridization. Why does it happen?
Mixing of orbitals.
To allow for all orbitals to be the same energy/strength
List the 6 strongest acids & 3 bases.
ACIDS: HCL HCLO4 HBR HF H2SO4 HNO3
BASES: Ca2OH KOH NaOH
T/F: water and amines can act as a base and an acid.
True!
What must a molecule contain to act as an acid? What about a base?
What must a molecule contain to act as an acid? H+ what about a base? Lone pairs
What are the 6 IUPAC rules for naming alkanes?
The longest continuous chain of carbons = main chain
Number the main chain carbons in the direction closest to the substituent to ensure low C #s
If multiple substituents, list them in alphabetical order when naming the alkane
If multiple chains of the same length, pick the chain that results in the most substituents
If multiple of the same substituent, use prefixes (di-,tri-,etc.)
If carbons #s the same goring in both directions, number in the direction closest to the substituent that comes first alphabetically
Draw the distinctive chemical composition of the following functional groups:
Alcohol, Amine, Aldehyde, Carboxylic acid, Ketone, Ether, Ester
Alcohol = R-O-H
Amine = R-N-R
Aldehyde - R-C(O hanging on carbon)-H
Carboxylic acid - R- (O hanging on carbon) - O - H
Ketone = R - C (O hanging on carbon) - R
Ether - R- O - R
Ester - R - O - C (O) - R\R
Define an acid & base by the bronsted-lowry definition. Explain how it differs from the lewis definition.
Acid = gives away its proton in a reaction (becomes more -) base = accepts proton in reaction ; All bases are lewis bases; lewis acid = accepts the share of electrons
Define pKa.
Measurement of acid strength in logarithmic form.
Define the position of equilibrium. What does equilibrium favor in acid-base reactions?
The direction the reaction is likely to go. Whichever side has the weaker acid (either the OG acid or conjugate acid)
Identify the hybridization of the central atom in each of the following:
a. CH₄
b. BF₃
c. C₂H₂
d. H₂O
a. CH₄ - sp3
b. BF₃ - sp2
c. C₂H₂ - sp2
d. H₂O - sp3