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.

101.

From the followings, which drug contain furan heterocyclic ring?

A. Furazolidine
B. Nitrofurantoin
C. Fluticazone
D. All of the above
Answer» E.
102.

Which of the following is NOT true of enantiomers? They have the same:

A. boiling point.
B. melting point.
C. specific rotation.
D. chemical reactivity toward achiral reagents.
Answer» E.
103.

Which drug(s) contain thiophene ring in its(their) structure?

A. Cephalothin
B. Cefoxitin
C. Temocillin
D. All of the above
Answer» E.
104.

Clotiazepam, CNS active agent, possess __________ heterocyclic ring.

A. Thiophene
B. Oxazole
C. Pyridine
D. Pyrrole
Answer» B. Oxazole
105.

Identify the given heterocyclic compound.

A. Furan
B. Pyrazole
C. Pyrrole
D. Pyridine
Answer» D. Pyridine
106.

A solution of 0.1 g/mL of a pure R enantiomer in a 1.0 dm (i.e., 10 cm) polarimeter rotates plane polarized light by +4.8°. What is the rotation observed on this solution in a 2 dm polarimeter?

A. +2.4°
B. +4.8°
C. +19°
D. +9.6°
Answer» E.
107.

Which of the statements below correctly describes an achiral molecule?

A. The molecule has a nonsuperimposable mirror image.
B. The molecule exhibits optical activity when it interacts with plane-polarized light.
C. The molecule has an enantiomer.
D. The molecule might be a meso form.
Answer» E.
108.

Which would be the intermediate in the following reaction?

A. Furan – 2 carboxide
B. Furan- 2 – carbinol
C. Furoic acid
D. None of the above
Answer» D. None of the above
109.

Absolute configuration of stereoisomer is denoted by__

A. R and S isomers
B. D and L isomers
C. d and l isomers
D. cis and tr
Answer» B. D and L isomers
110.

Which of the following statements correctly pertains to a pair of enantiomers?

A. They rotate the plane of polarized light by exactly the same amount and in opposite directions.
B. They rotate the plane of polarized light by differing amounts and in opposite directions.
C. They rotate the plane of polarized light by differing amounts and in the same direction.
D. They have different melting points.
Answer» B. They rotate the plane of polarized light by differing amounts and in opposite directions.
111.

Which of the following groups has the highest priority according to the Cahn-Ingold-Prelogsequence rules?

A. CH3
B. CH2Cl
C. CH2OH
D. CHO
Answer» E.
112.

How many stereoisomers of 3-bromo-2-butanol, CH3CH(OH)CHBrCH3, exist?

A. 3
B. 1
C. 2
D. 4
Answer» E.
113.

The hydrogens lying in the plane of the cyclohexane ring are called____

A. Axial hydrogens
B. Chiral hydrogens
C. Equatorial hydrogens
D. None of the above
Answer» D. None of the above
114.

Which is the most reactive five membered heterocyclic compound?

A. Pyrrole
B. Furan
C. Thiophene
D. Pyridine
Answer» B. Furan
115.

(2R,4S) –2,4–Dichloropentane and (2S,4R)-2,4-dichloropentane are:

A. Enantiomers
B. Diastereomers
C. identical
D. conformational isomers
Answer» D. conformational isomers
116.

Which of the following statements is (are) true for the compound cis-1,2-dichlorocyclopropane?

A. This compound is chiral.
B. The enantiomer of this compound is trans-1,2-dichlorocyclopropane.
C. This compound contains no asymmetric carbons.
D. none of the above
Answer» E.
117.

Catalytic reduction of furan gives______

A. 2,3 – dihydro furan
B. 2,5 – dihydro furan
C. Tetra hydro furan
D. 3,4 – dihydro furan
Answer» D. 3,4 – dihydro furan
118.

Identify the following reaction:

A. Cannizaro reaction
B. Benzoin condensation
C. Gomberg reaction
D. Mercuration
Answer» B. Benzoin condensation
119.

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
120.

What can be said with certainty if a compound has [!] D/25 = -9.25º ?

A. The compound has the (S) configuration.
B. The compound has the (R) configuration.
C. The compound is not a meso form.
D. The compound possesses only one stereogenic center.
Answer» D. The compound possesses only one stereogenic center.
121.

CH3CHBrCH2CHClCH3 is the generalized representation of what number of stereo isomers?

A. 3
B. 4
C. 5
D. 6
Answer» C. 5
122.

What is the name of the following reaction?

A. Gattermann reaction
B. Riemer tiemann reaction
C. Friedal craft reaction
D. Blanc’s chloromethylation
Answer» B. Riemer tiemann reaction
123.

Pyrrole probably undergoes to ___________ reaction.

A. Electrophilic substitution
B. Nucleophilic substitution
C. Electrophilic addition
D. Nucleophilic addition
Answer» B. Nucleophilic substitution
124.

Identify the reaction: when furan react with aryl diazonium chloride in the presence ofstrong alkali to produce 2 – aryl furan.

A. Mercuration
B. Gattermann Koch reaction
C. Kolbe reaction
D. Gomberg reaction
Answer» E.
125.

Thiophene shows electrophilic substitution reactions mainly at position___.

A. C2
B. C3
C. C4
D. C5
Answer» B. C3
126.

Which condition is appropriate for the nitration of thiophene?

A. Acetyl nitrate
B. Nitric acid +acetic anhydride
C. Concentrated nitric acid
D. Sodium nitrate
Answer» C. Concentrated nitric acid
127.

What is the percent composition of a mixture of (S)-(+)-2-butanol, α= +13.52°, and (R)-(-)-2-butanol, α = -13.52°, with a specific rotation α = +6.76°?

A. 75%(R) 25%(S)
B. 25%(R) 75%(S)
C. 50%(R) 50%(S)
D. 67%(R) 33%(S)
Answer» B. 25%(R) 75%(S)
128.

The hydrogens lying above or below the plane of the cyclohexane ring are called____

A. Axial hydrogens
B. Chiral hydrogens
C. Equatorial hydrogens
D. None of the above
Answer» B. Chiral hydrogens
129.

Relative configuration of stereoisomer is denoted by__

A. R and S isomers
B. D and L isomers
C. d and l isomers
D. cis and tr
Answer» B. D and L isomers
130.

Sulfonation of thiophene can be carried out by using______________.

A. SO3 +Conc. HCl
B. Dilute Sulphuric acid
C. Concentrated Sulphuric acid
D. SO3 + HNO3
Answer» D. SO3 + HNO3
131.

Which is the following heterocyclic compound?

A. Thiophene
B. Thiazole
C. Furan
D. Pyrrole
Answer» B. Thiazole
132.

The process of separation of a racemic mixture into optically active d and l isomers is___

A. Racemization
B. Resolution
C. Both (a) and (b)
D. None of the above
Answer» C. Both (a) and (b)
133.

Which is the true sentence for stereospecific reactions from the followings,

A. Reactants react at different rate i.e. they have different rate of reaction.
B. They give different stereoisomers as products.
C. They have different paths to give different types of compounds as products.
D. All of the above
Answer» E.
134.

What term describes the structural relationship between (E)- and (Z)-2-pentene?

A. Constitutional isomers
B. Enantiomers
C. Geometric isomers
D. Conformers
Answer» D. Conformers
135.

Complete the reaction:

A. Br2
B. HBr
C. KBr in alcohol
D. NaBr in pyridine
Answer» B. HBr
136.

What can be said with certainty if a compound has α= -9.25°?

A. The compound has the (S) configuration
B. The compound has the (R) configuration
C. The compound is not a meso form
D. The compound possesses only one stereogenic center
Answer» D. The compound possesses only one stereogenic center
137.

What would be the appropriate reaction condition for the following reaction;

A. SO2/AlCl3/673K
B. H2S/AlCl3/273K
C. H2S/Al2O3/673K
D. Sulphur/heat
Answer» D. Sulphur/heat
138.

Thiophene & its derivatives show following pharmacological activity.

A. Sedative
B. Hypnotic
C. Anticonvulsant activity
D. All of the above
Answer» E.
139.

How many possible stereoisomers for the compound CH3CH(OH)COOH.

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
140.

Which of the following molecules is achiral?

A. (2R,3R)-2,3-Dichloropentane
B. (2R,3S)-2,3-Dichloropentane
C. (2S,4S)-2,4-Dichloropentane
D. (2S,4R)-2,4-Dichloropentane
Answer» E.
141.

In the absence of specific data, it can only be said that (R)–2–bromopentane is:

A. dextrorotatory (+).
B. levorotatory (–).
C. analogous in absolute configuration to (R)–2–bromopentane.
D. optically inactive.
Answer» D. optically inactive.
142.

Which of the followings statements is correct?

A. Pyrrole has less aromatic character than furan
B. Pyridine is isoelectronic with benzene
C. Pyridine is tertiary amine
D. Pyrrole is strong base
Answer» D. Pyrrole is strong base
143.

A mixture of equal amounts of two enantiomers __________.

A. is called a racemic mixture
B. is optically inactive
C. implies that the enantiomers are meso forms
D. both A and B
Answer» E.
144.

Which of these is a comparatively insignificant factor affecting the magnitude of specific optical rotation.

A. Concentration of substance of interest
B. Temperature of measurement
C. Length of the sample tube
D. All of the above
Answer» E.
145.

Which symmetry element makes the given compound achiral?

A. Plane of symmetry (POS)
B. Center of symmetry (COS)
C. Axis of symmetry (AOS)
D. Alternating axis of symmetry (AAOS)
Answer» B. Center of symmetry (COS)
146.

Prazocin, sympatholytic drug contain__________heterocyclic ring.

A. Furan
B. Pyrrole
C. Oxazole
D. Indole
Answer» B. Pyrrole
147.

What will be the product of the following reaction?

A. 5 – bromo thiophene
B. 3- bromo thiophene
C. 2 – bromo thiophene
D. 2,5 – di bromo thiophene
Answer» D. 2,5 – di bromo thiophene
148.

Five membered rings come under which category of heterocycle classification on the basisof chemical behavior?

A. -excessive heterocycle
B. -deficient heterocycle
C. -equivalent heterocycle
D. Can’t say about the five membered rings
Answer» B. -deficient heterocycle
149.

Which of the following terms correctly describe(s) the structural relationship between cis-1,3- dimethylcyclopentane and trans-1,3-dimethylcyclopentane?

A. enantiomers
B. diastereomers
C. geometric isomers
D. both B and C
Answer» E.
150.

What would be the product of following reaction?

A. Thiophene
B. Thiazole
C. Purine
D. Pyrimidine
Answer» B. Thiazole