Organic Chemistry Exam Review

Dipole Moments

100

Which bond has the Largest dipole moment?

C-H

C-F

C-Cl

C-Br

What is C-F

200

Doed CCl₄ have a dipole moment?

No

300

For CH₃COCH₃, draw the net dipole moment?

Pointing to the middle oxygen

400

Which molecule has the biggest dipole moment?

cis-1,2-dichloroethane

trans-1,2-dichloroethane

cis-1,2-dichloroethane

500

Which molecule has the highest boiling poing: CH₃CH₂CH₃, CH₃OCH₃, CH₃CH₂OH, CH₃CH₂Cl 

CH₃CH₂OH

Molecular Geometry

100

What is the molecular geometry around each carbon atom in ethane (CH₃CH₃)?

Tetrahedral

200

What is the molecular geometry around each carbon in ethene (CH₂=CH₂)?

Trigonal Planar

300

What is the molecular geometry around the nitrogen atom in methylamine (CH₃NH₂)?

Trigonal Pyrimidal

400

Consider CH₂=CH–CH=CH₂ (1,3-butadiene).

Question:
What is the approximate bond angle around each carbon in the molecule?

A. 90°
B. 109.5°
C. 120°
D. 180°

C. 120

500

What is the hybridization of each atom in the molecule CH₃CH₂CONH₂?

Sp3, Sp3, Sp2, Sp2

Functional Groups

100

What functional group is present in the following molecule?

CH₃CH₂OH

Alcohol

200

Identify all functional groups present in:

HO–CH₂–CH₂–COOH

• Alcohol — –OH

• Carboxylic acid — –COOH

300

Which molecule contains an aldehyde?

A. CH₃COCH₃
B. CH₃CH₂OH
C. CH₃CH₂CHO
D. CH₃COOCH₃

C. CH₃CH₂CHO

400

Identify all of the functional groups in:

HO–CH₂–CH=CH–COO–CH₃

• Alcohol — –OH

• Alkene — C=C

• Ester — –COO–

500

Consider the molecule:

H₂N–CH₂–CH₂–CO–NH–CH₃

Identify the functional group(s)

Be Specific!

Primary Amine, amide

Resonance

100

Which molecule has resonance?

A. CH₄
B. CH₃CH₃
C. CH₂=CH–CH=CH₂
D. CH₃CH₂OH

C. CH₂=CH–CH=CH₂

200

Draw all important resonance structures for the acetate ion, CH₃COO⁻.

The negative charge can be placed on either oxygen:

300

Which atom provides the lone pair that allows resonance in the following ion?

CH2=CH−CH2+

Answer: There is no lone pair involved.

400

Which resonance structure is the major contributor?

CH3−C(=O)−NH2 

CH3−C(=O)−NH2

500

Which of the following is the major resonance contributor for the nitrite ion, NO₂⁻?

O=N−O−

−O−N=O 

Acid/base reactions

100

Consider the reaction:

HCl+H2O→H3O++Cl− 

What is the base, acid, conjugate base, and conjugate acid?

A, B, CA, CB

200

For the reaction:

CH3COOH+NH3⇌CH3COO−+NH4 

Draw the electron pushing arrows

Yes

300

Consider:

CH3COOH + NH2−⇌CH3COO− + NH3+

Which direction is favored?

Strongly to the right

400

Consider the acid–base reaction:

CH3COOH+NH3⇌CH3COO−+NH4+

Given:

• pKa(CH3COOH)=4.76
• pKa(NH4+)=9.25

Estimate KeqK_{eq}.

3.1*10⁴

500

Consider:

HA+B−⇌A−+HB

• HA:pKa=5
• HB:pKa=12

What is the approximate Keq

10⁷