Explore topic-wise MCQs in Current Affairs.

This section includes 2539 Mcqs, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

51.

Which pharmacological effect is not produced by thiophene derivatives?

A. Anticoagulants
B. Diuretics
C. Coagulants
D. Anti asthmatics
Answer» D. Anti asthmatics
Discussion
52.

What is the stereochemical relationship between the following two molecules?

A. Geometrical isomers
B. Enantiomers
C. Diastereomers
D. Identical
Answer» E.
Discussion
53.

Which compound would show optical activity?

A. cis 1,4- Dimethylcyclohexane
B. trans 1,4- Dimethylcyclohexane
C. cis 1,4- Dimethylcycloheptane
D. tr
Answer» E.
Discussion
54.

Of the compounds which correspond to the general name "dichlorocyclobutane", how many areoptically active?

A. 0
B. 1
C. 2
D. 3
Answer» D. 3
Discussion
55.

Thiophene probably undergoes to ___________ reaction.

A. Electrophilic substitution
B. Nucleophilic substitution
C. Electrophilic addition
D. Nucleophilic addition
Answer» B. Nucleophilic substitution
Discussion
56.

The necessary conditions for geometric isomers are__

A. Presence of at least one double bond.
B. Each carbon atom of the double bond should be linked to two different atoms or groups.
C. Both (a) and (b)
D. None of the above.
Answer» D. None of the above.
Discussion
57.

Those stereoisomers which can be interconverted only by breaking and remaking of covalentbonds are called as____

A. Chain isomers
B. Positional isomers
C. Configurational isomers
D. Conformational isomers
Answer» D. Conformational isomers
Discussion
58.

Which drug of following does not contain furan ring?

A. Furazolidone
B. Lorpiprazole
C. Terazocin
D. Dantrolene
Answer» C. Terazocin
Discussion
59.

Enantiomers are:

A. Molecules that have a mirror image.
B. Molecules that have at least one stereogenic center.
C. Non-superposable molecules.
D. Non-superposable molecules that are mirror images of each other.
Answer» E.
Discussion
60.

Identify the reaction: When thiophene react with dimethyl formamide in the presence of POCl3, it will produce thiophene – 2 – carboxaldehyde.

A. Kolbe reaction
B. Canizzaro reaction
C. Gattermann Koch reaction
D. Vilsmeir – Hoack reaction
Answer» E.
Discussion
61.

Pyrrole is reduced by using Zn and acetic acid to get product_______

A. 2 – pyrroline
B. 3 – pyrroline
C. Pyrrolidine
D. All of the above
Answer» C. Pyrrolidine
Discussion
62.

What would be the reducing agent for the following reduction of thiophene?

A. Na + ammonia
B. Hydrogen gas + Ni
C. Pd + ammonia
D. Pd + Hydrogen gas
Answer» B. Hydrogen gas + Ni
Discussion
63.

How many enantiomers are there of the molecule shown below?

A. 0
B. 2
C. 4
D. 6
Answer» B. 2
Discussion
64.

What is the molecular formula for the alkenes of smallest molecular weight which possesses astereogenic center?

A. C4H10
B. C5H12
C. C6H14
D. C7H16
Answer» E.
Discussion
65.

Which is least basic compound?

A. Pyridine
B. Pyrrole
C. Imidazole
D. Pyrrolidine
Answer» C. Imidazole
Discussion
66.

Bromination of furan by using Br2 will produce_________.

A. 2 – bromo furan
B. 3 – bromo furan
C. 2,5 – dibromo furan
D. None of the above
Answer» E.
Discussion
67.

How many asymmetric carbon atoms are present in the following compound?

A. 0
B. 1
C. 2
D. 3
Answer» C. 2
Discussion
68.

Which of the following is capable of existing as a pair of enantiomers?

A. 2-methylpropane
B. 2-methylpentane
C. 3-methylpentane
D. 3-methylhexane
Answer» E.
Discussion
69.

How many chiral stereoisomers can be drawn for CH3CHFCHFCH(CH3)2?

A. 2
B. 4
C. 6
D. 8
Answer» C. 6
Discussion
70.

Friedel craft acetylation of furan by using acetic anhydride is carried out in the presence of catalyst______.

A. AlCl3
B. FeCl3
C. BF3
D. LIAlH4
Answer» D. LIAlH4
Discussion
71.

What is the relationship between the two groups in the following molecules?

A. They are equatorial to one another
B. They are axial to one another
C. They are cis to one another
D. They are tr
Answer» B. They are axial to one another
Discussion
72.

Pilocarpine, cholinergic agonist, contains________heterocyclic ring.

A. Furan
B. Pyrrole
C. Thiophene
D. Purine
Answer» B. Pyrrole
Discussion
73.

If a solution of a compound (30.0 g/100 mL of solution) has a measured rotation of +15º in a 2 dmtube, the specific rotation is:

A. +50º
B. +25º
C. +15º
D. +7.5º
Answer» C. +15º
Discussion
74.

Which of these is a comparatively insignificant factor affecting the magnitude of Specific optical rotation?

A. Concentration of the substance of interest
B. Purity of the sample
C. Temperature of the measurement
D. Length of the sample tube
Answer» D. Length of the sample tube
Discussion
75.

Pyrrole undergoes iodination in presence of Iodine and potassium iodide to produce_____.

A. 2 – iodo pyrrole
B. 3 – iodo pyrrole
C. Tetra iodo pyrrole
D. Tri iodo pyrrole
Answer» D. Tri iodo pyrrole
Discussion
76.

What is not true about thiophene from the following sentences?

A. Thiophene shows aromaticity.
B. Thiophene contains oxygen heteroatom.
C. Thiophene has diene like structure.
D. Thiophene has a flat pentagonal ring.
Answer» C. Thiophene has diene like structure.
Discussion
77.

How many stereoisomers of 2,3-butanediol, CH3CH(OH)CH(OH)CH3, exist?

A. 3
B. 4
C. 1
D. 2
Answer» B. 4
Discussion
78.

Which heterocyclic ring is present in Rofecoxib, NSAID?

A. Pyrrole
B. Furan
C. Purine
D. Indole
Answer» C. Purine
Discussion
79.

Which is the true statement from followings?

A. Thiophene is more stable than pyrrole
B. Thiophene is more stable than furan
C. Both (a) & (b)
D. None of the above
Answer» D. None of the above
Discussion
80.

Ratio of dextro and levo isomers (d:l) of compound present in raceme mixture is__

A. 50:50
B. 40:60
C. 30:70
D. 20:80
Answer» B. 40:60
Discussion
81.

Which heteroatom present in thiophene?

A. Nitrogen
B. Silicon
C. Oxygen
D. Sulphur
Answer» E.
Discussion
82.

Hexane and 3-methylpentane are examples of:

A. enantiomers.
B. stereoisomers.
C. diastereomers.
D. constitutional isomers.
Answer» E.
Discussion
83.

Furan probably undergoes to ___________ reaction.

A. Electrophilic substitution
B. Nucleophilic substitution
C. Electrophilic addition
D. Nucleophilic addition
Answer» B. Nucleophilic substitution
Discussion
84.

Which drug(s) possess pyrrole heterocyclic compound from the followings?

A. Captopril
B. Lincomycin
C. Triprolidine
D. All of the above
Answer» E.
Discussion
85.

From the followings, which is true about conformational isomers?

A. Eclipsed conformation is more stable than staggered conformation.
B. Eclipsed conformation is less stable than staggered conformation.
C. Eclipsed conformation has low energy than staggered conformation.
D. None of the above
Answer» C. Eclipsed conformation has low energy than staggered conformation.
Discussion
86.

Which instrument is used to measure angle of rotation?

A. Polarimeter
B. UV spectrometer
C. pH meter
D. Conductometer
Answer» B. UV spectrometer
Discussion
87.

Pyrrole potassium on treatment with CO2 under pressure give mixture of 2 and 3 pyrrole – carboxylic acid, identify the reaction.

A. Kolbe-Schmidt reaction
B. Reamer-Tiemann reaction
C. Gattermann Koch reaction
D. Coupling reaction
Answer» B. Reamer-Tiemann reaction
Discussion
88.

Bepridil, calcium channel blocker, contain heterocyclic ring_____

A. Pyrrole
B. Purine
C. Indole
D. Pyridine
Answer» B. Purine
Discussion
89.

Which of the following statements most accurately describes the stereochemistry between the various cyclohexanes?

A. Cis-1,2-dichlorocyclohexane and trans-1,2-dichlorocyclohexane rotate plane-polarized light in opposite directions, and together in equal proportions form a racemic mixture.
B. The diaxial and diequatorial forms of trans-1,3-dichlorohexane can be separated by their differing physical properties.
C. Only cis-1,4-dichlorocyclohexane is achiral due to a plane of symmetry, and cis-1,4- dichlorocyclohexane is diastereomeric to trans-1,4-dichlorocyclohexane.
D. The conformational isomers of tr
Answer» E.
Discussion
90.

How many different compounds are there which correspond to the general name "3-(1- methylbutyl)cyclobutanol”?

A. 2
B. 4
C. 6
D. 8
Answer» C. 6
Discussion
91.

How many diastereomers are there of the molecule shown below?

A. 0
B. 2
C. 4
D. 6
Answer» E.
Discussion
92.

How many discrete dimethylcyclopropanes are there?

A. 2
B. 3
C. 4
D. 5
Answer» D. 5
Discussion
93.

A beam of light having a particular wavelength and having vibrations only in one plane is____

A. Ordinary light
B. Plane polarized light
C. Monochromatic light
D. None of above
Answer» C. Monochromatic light
Discussion
94.

For the generalized structure BrCH2CHClCH2CHClCH2Br there exists what number ofstereoisomers?

A. 2
B. 3
C. 4
D. 6
Answer» D. 6
Discussion
95.

By studying which physical property, configuration of geometric isomers can be determined

A. Melting point
B. Solubility
C. Dipole moment
D. All of the above
Answer» E.
Discussion
96.

Those stereoisomers which can be interconverted by simple rotation about sigma bonds are called as____

A. Conformational isomers
B. Functional isomers
C. Geometric isomers
D. Tautomers
Answer» B. Functional isomers
Discussion
97.

__________ is the use of an optically active reagent or catalyst to convert an optically inactivestarting material into an optically active product.

A. Asymmetric induction
B. Racemization
C. Optical reduction
D. Meso effection
Answer» B. Racemization
Discussion
98.

Which statement is true for 1,3-dimethylcyclobutane?

A. Only one form of the compound is possible
B. Two diastereomeric forms are possible.
C. Two enantiomeric forms and one meso compound are possible.
D. None of the above.
Answer» C. Two enantiomeric forms and one meso compound are possible.
Discussion
99.

Which reagent is used for the nitration of furan?

A. Conc. Nitric acid and sulphuric acid
B. Acetyl nitrate
C. Nitrobenzene
D. Dilute nitric acid with benzene
Answer» C. Nitrobenzene
Discussion
100.

Cis-trans isomers are:

A. Diastereomers.
B. Enantiomers.
C. Geometric isomers.
D. Constitutional isomers.
Answer» D. Constitutional isomers.
Discussion