Mesomeric Effect

Mesomeric effect is the process of electron density redistribution i.e. addition or removal of electron density, occuring, through a pi-orbital through conjugated systems.

Inductive effect

When electron density in a molecule is shifted, as a result of the polarization of a bond by a nearby electropositive or electronegative atom then it is known as inductive effect.

Steric effect

Steric effect is the change in the reactivity and preferred shape of the molecule as a result of the overlapping of electron clouds in a molecule, when atoms are brought closer together.

Hyperconjugation

It is a weak form of conjugation resulted from the ineraction of electrons in a sigma-bond with neighbouring empty pie-orbital or p-orbital resulting in an increased stability of the system.

Conjugation

Basically, Conjugation refers to joining  together of two things.
In organic chemistry, we refer conjugation to a system which is joined together with alternate single and multiple bonds.

Pharmaceutical Organic Chemistry

Multiple Choice Question (MCQs) of Organic Pharmaceutical Chemistry

1. The analgesic action of aspirin is removed, if

a. Carboxyl group is removed
b. Acetoxy group is removed
c. Carboxyl group is not attached on ortho position
d. All of the above
--------------------
2. Diastereoisomerism and enantiomorphism is shown in

a. Ephedrine and pseudoephedrine
b. D and L-ephedrine
c. Ephedrine & pseudoephedrine and D & L-ephedrine respectively
d. D & L-ephedrine and Ephedrine & pseudoephedrine respectively
--------------------
3. Caffeine is presented as a/an

a. Purine derivative
b. Pyrimidine derivative
c. Imidazole derivative
d. both b and c
--------------------
4. A group that can donate an electron pair is

a. Bronsted acid
b. Bronsted base
c. Lewis acid
d. Lewis base
--------------------
5. Hendersen-Hasselbalch equation is represented by

a. Ka = [A][H+]/[HA]
b. pKa + pKb = 14
c. pKa = pH + log [HA]/[A-]
d. both a and c
--------------------
6. Which of the following is through space-effects on polarizability due to electronegativity differences?

a. Field effect
b. Inductive effect
c. Resonance effect
d. Polarizability
--------------------
7. Which of the following is the ease of distortion of the electron cloud?

a. Field effect
b. Inductive effect
c. Resonance effect
d. Polarizability
--------------------
8. Which of the following occurs as a result of electronegativity differences?

a. Field effect
b. Inductive effect
c. Resonance effect
d. None of the above
--------------------
9. Which of the following involves the actual movement of electrons through a pie-bond system?

a. Field effect
b. Inductive effect
c. Resonance effect
d. None of the above
--------------------
10. The movement of electrons through a conjugated system allows for charges to be dispersed over several atoms. This phenomenon is

a. Localization
b. Delocalization
c. Polarization
d. Depolarization
--------------------
11. Which of the following is less influenced by distance?

a. Field effect
b. Inductive effect
c. Resonance effect
d. both a and c
--------------------
12. Which of the following is a carbonyl based group?

a. esters
b. nitro-
c. alcohols
d. ethers
--------------------
13. Which of the following shows electron withdrawing groups?

a. phenyl
b. ethers
c. amines
d. alkyl groups
--------------------
14. Which of the following shows electron donating group?

a. amides
b. esters
c. ketones
d. amines
--------------------
15. Which of the following has minimum pKa value or maximum acidic strength?

a. imide
b. sulphonamide
c. N-arylsulfonamide
d. sulfonimide
--------------------
16. sigma-bonding electrons, especially those from C-H bonds can be donated in a process known as

a. conjugation
b. hyperconjugation
c. polarization
d. depolarization
--------------------
17. Which of the following has neutral pKa value?

a. Water
b. Ether
c. Amide
d. All of the above
--------------------

Answers to multiple choice questions (MCQs) in Organic Pharmaceutical Chemistry

1. d
2. c
3. a
4. d
5. c
6. a
7. d
8. b
9. c
10. b
11. c
12. a
13. a
14. d
15. d
16. b
17. d

(These MCQs are helpful for the preparation of Organic Pharmaceutical Chemistry Exams)

Further reading:
Pharmaceutical Organic Chemistry

Wilson & Gisvold's Textbook of Organic Medicinal and Pharmaceutical Chemistry (Wilson and Gisvold's Textbook of Organic and Pharmaceutical Chemistry)

Texbook of Pharmaceutical Organic Chemistry

Inorganic and Organic Chemistry: " A " Level Multiple Choice Questions

Ace Organic Chemistry (Multiple Choice Questions)