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Draw the resonance structure indicated by the arrows.
1)
2)O
O
3) O O
Label each atom with the correct hybridization.
4)
HOO
sp3
sp3
sp3
sp3
sp3
sp3
N
5) sp3
sp3
sp2 sp2
6) O
sp3
sp2
sp2
spsp
7) Draw H2NCH2+ in its second best resonance structure.
N CH2
H
H
N CH2
H
H
N CH2
H
H
8) Draw the best Lewis structure for CH3CHO, a neutral molecule
H3C
C
O
H
9) Draw the Lewis structure for CH3COOH, a neutral molecule.
H3C
C
O
OH
10) Draw the Lewis structure for N2H2, a neutral molecule.
HN NH
11) Draw in the electron flow arrows in on the left hand structure that lead to the resonance structure on the right.
OO
12) In the empty box, draw the best resonance structure of the left-hand compound, and draw one or more electron-flow arrows on the preexisting structure that lead to the new structure.
OO
O O
13)
14)
Cl Cl
ClCl
Cl
ClClCl
1
234
Label each of the following as an ionic or covalently bonded compound.
a) NaF
b) BrCl
c) NaOCHe
ionic
covalent
ionic
Calculate the formal charge of nitrogen in each of the following compounds.
a)
b)
NFC = 5 – (4 + (1/2(4))) = -1
N N
FC = 5 – (0 + (1/2(8))) = +1
FC = 5 – (2 + (1/2(6))) = 0
Draw the Lewis structure.
a) (CH3(OH2))+
b) CH3NO2
C O
H
H
H
H
H
C N
H
H
H
O
O
Draw all possible isomers of C2H4O.
H3C
C
O
H
CH2CH
HO
H2C CH2
O
Are each of the following pairs isomers or resonance structures?
a)
b)
H3C
CH2
CH3 H3C
CH2
CH2
Neither, different formulas
O O
Isomers, same formula but different arrangement of atoms.
Draw a resonance structure of each, and identify which is the major contributor.
a)
b)
O
NH2H
O
NH2H
H3C C
O
CH
CH2H3C C
O
CH
CH2
Draw all possible resonance structures of the compound below and it’s resonance hybrid.
CH2CH2 CH2 CH2
CH2
CH2
Predict the geometry around each indicated atom.
a)
b)
H3C
H2C
CH2
CH3
tetrahderal
CH2
H3C OH
Trigonal planar
Draw the three dimensional structure of the following.
a) CH3OH
b) (CH3)2NH
H
C
O
H H
H
H
C
N
H H
H
H
HH
Convert each molecule into a skeletal structure.
a) (CH3)2CHCH2CH2CH(CH3)2
b)
C CH3C
H
H
H H
H
H
HCH
CH3
H3C
H
Convert into Lewis structures.
a) (CH3)3COH
b) CH3COCH2Br
H3C
CH3
CH3
O H
OH
H
H
H
H
Br
What is the hybridizatio of th eindicated atom.
a)
b)
sp2
sp3
CO2H
sp
sp2
Which is the weakest of the indicated bonds?
a bc
A is the weakest bond due to it being composed of a sp3 and sp2 hybridized orbital, thus having the least amount of S character
HO
NH2
ab
B is the weakest, b/c bond strength increases across a row in the periodic table and N is to the left of O.
Draw the products and label each part.
O
OH
+ OCH3
O
O
+ HOCH3
ACBB CA
+HNaNH2
+ NH3
Na
ACB
BCA
Draw the products and determine if the reaction occurs.
F3C
O
OH
+ O CH2CH3
F3C
O
O
+ HO CH2CH3
pka=0.2 pka=16Products favored
O
OH
+ NaClO
O
+ HCl
pka=5
pka=-7
reactants favored
Which is the strongest base?
HBr, HCl or HF
HF, b/c it is the weakest acid.
Identify the most acidic hydrogen.
H
H
H
H
H
a
b
c
C is the most acidic hydrogen b/c it’s bonded to an sp hybridized carbon.
Draw the products of each reaction and label the starting materials as a Lewis acid and base.
Cl +Cl
B
Cl Cl
Cl
BCl Cl
ClLB
LA
O +
Cl
B
Cl ClO
Cl
B
Cl
ClLB LA
1) Complete the following acid-base reaction.
O+
OH
OH+
O
2) Complete the following acid-base reaction. Draw only the organic products.
OH
KOH
O
OHH
O+ H
O
HK
3)
OH
O
H OH + OH
4) Choose the strongest acid.
H Cl H BrS
HH
H BrBoth Cl and Br are further right than S. And Br is further down than Cl. So most acidic.
5)OH PH2 SH
SH Both O and S are further right than P. And S is further down than O. So most acidic.
6) Choose the weakest acid.
OH SH CH3
CH3 C is further left than O and S so weakest acid.
7) The following compound has two stereoisomers. One has a dipole of 0 D, and the other has a dipole moment of 2.95 D. Draw the structure of the stereoisomer with dipole moment of 2.95 D.
Cl Cl
Cl
H
H
Cl
Cl
H
Cl
H
Cl
H
H
Cl
Cl
H
Cl
H
OH SiH3 CH3
8) Rank the three compounds from least acidic (rank 1) to most.
123
We know Si is more acidic than C because it is below C in the same column. Although Si and O can’t be compared directly, O is much more acidic.
9) Rank the following compounds from most acidic (rank 1) to least.
H3CH2C
O
OH
Cl
H3CH2C
O
OH
Br
H3CH2C
O
OH
OH
H3CH2C
H2C
O
OH
1
2 3
4
Acidity is based on the electron withdrawing effect of the four different substituents. O is the most electronegative, furthest up and to the right, and thus gives the most acidic compd. And Cl is more electronegative than Br b/c electronegativity increases up the column.
10) Draw the electron-flow arrows that lead from starting materials to products in this acid–base reaction.
H HN
H
H
H N
H
H
H
11)
N
O
O
H
NH
O
O
1) Draw an aldehyde.
R
O
H
RCHO
2) Draw an ester.
R
O
O
R
RCOOR or RCO2R
3) Draw a sulfide.
R
S
RRSR
4) Draw 1,1-dimethylcyclohexane.
5) Draw 2,2,4-trimethylhexane.
6) Draw trans-1,3-dibromocyclobutane. Br
BrBrH
Br H
HBr
H BrBr
Br
7) Draw cis-1-chloro-3-isopropylcyclopentane.
ClCl
Cl
HH
H
Cl
H
8) Draw sec-butylcycloheptane
9) Draw 2,2,4,4-tetramethylhexane
10) Draw the structural formula of an alkane that has eight carbons and only primary hydrogens.
CH3
CH3
H3C
CH3
CH3
CH3
Primary hydrogens are attached to carbons attached to only one other carbon.
11) Draw the conformation favored by 1,2-dichloroethane at equilibrium in the liquid phase by following this procedure.
Cl
H H
Cl
HH
H
Cl H
Cl
HH
anit gauche
The gauche conformer is favored in the liquid phase due to a polar effect. However, for this class I would accept the anit conformer as your answer, which would be correct if in the gas form.
12) Draw cis-3-ethyl-1-isopropylcyclohexane in its lowest energy conformation
H
H
13) Draw trans-1-bromo-3-methylcyclohexane in its lowest energy conformation
CH3
HH
Br
1) Draw the Lewis structure of HNO3.
O
NHO O
2) What is the formal charge of the following compound?
H C
H
H
FC = 4 – (2 + (1/2)(6)) = -1
3) Draw all resonance structures O
OO O
O
4) What are the hybridizations of the numbered carbons?
12
sp3
sp2
5) Which of the following compounds has the largest net dipole? Draw the contributing dipoles of the compound you choose.
CO2 H2O CHCl3
H
O
H
6) Draw the product of the following reaction. (Label the Lewis Acid and Base)
OH
LA LB
7) Which molecule plays the role of acid?
HNO3 + H2SO4 → HSO4– + H2NO3
+
acid
8) Using pKa values from the table, determine if the following
reaction will occur.
pKa HA
3.7 HCOOH
4.2 C6H5COOH
4.75 CH3COOH
15.5 CH3OH
O
OH
+ NaOCH3
HO CH3 +
O
O
4.75
15.5
pKa of the conjugate acid is larger than that of the acid so the
reaction favors the products.
9) Which is the strongest base?
LiOH LiF LiCH3
LiCH3 is the strongest base because the acid it forms when the anion is
protonated is very weak.
10) What intermolecular forces does the following molecule exhibit?
O
O
It possesses Van der Waals and dipole-dipole interactions.
11) Which of the following has the highest boiling and why?
CBr3CH3 CH3OCH3 CH3NH2
CH3NH2 has the highest boiling point because it possesses the same
intermolecular forces as the first two molecules, but also has hydrogen bonding capabilities.
12) Label the electrophile and nucleophile. Then if the reaction occurs, draw the products.
O
+ CH3
NuE
O
13) Name the following compound.
2-sec-butyl-4-ethyl-1-methylcyclohexane
14) Which of the following has the highest melting point? Why?
a) 2-methylbutane
b) 2,2',3-dimethylbutane
c) 2,2',3,3'-tetramethylbutane
c) 2,2',3,3'-tetramethylbutane has the highest metlign point due to its high symmetry giving it the ability to pack close together in the crystal lattice.
15) Draw 2-chloro-4-ethyl-3-methylheptane
Cl
Draw the most stable form of trans-1-bromo-3-ethylcyclohexane.
H
H
H
H
Br
H
H
H
H
H
H
HH
H
H
H
H
H
H
Br
H
H
More stable
Using Newman projections, draw all the staggered conformations of 1-chloropropane, label the anti and gauche forms.
Cl
1
2
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