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.

251.

Methyl alcohol is toxic. The reason assigned is………

A. It stops respiratory track
B. It reacts with nitrogen and forms CN in the lungs
C. It increases CO2 content in the blood
D. It is a reduction product of formaldehyde
Answer» C. It increases CO2 content in the blood
252.

Ethyl alcohol exhibits acidic character on reacting with…….

A. Acetic acid
B. Sodium metal
C. Hydrogen iodide
D. Acidic potassium dichromate
Answer» C. Hydrogen iodide
253.

The fermentation of starch to give alcohol occurs mainly with the help of ………

A. O2
B. Air
C. CO2
D. Enzymes
Answer» E.
254.

What is freon-12…….

A. Pesticide
B. Refrigerant
C. Solvent
D. Lubricant
Answer» C. Solvent
255.

Of the five isomeric hexanes, the isomer which can give two monochlorinated compoundsis…………..

A. n-hexane
B. 2, 3-dimethylbutane
C. 2, 2-dimethylbutane
D. 2-methylpentane
Answer» C. 2, 2-dimethylbutane
256.

Alkenes convert into alcohols by……

A. Hydrolysis by dil. Sulphuric acid
B. Hydration of alkene by alkaline KMnO4
C. Hydrolysis by water vapours and conc. Sulphuric acid
D. Hydration of alkene by aqueous KOH
Answer» C. Hydrolysis by water vapours and conc. Sulphuric acid
257.

Which statement is not true concerning alkanes………..

A. Large number alkanes are soluble in water
B. All alkanes have a lower density than water
C. At room temperature some alkanes are liquids, some solids and some gases
D. All alkanes burn
Answer» B. All alkanes have a lower density than water
258.

The oxidation of toluene to benzaldehyde by chromyl chloride is called……..

A. Cannizzaro reaction
B. Wurtz reaction
C. Etard reaction
D. Reimer-Tiemann reaction
Answer» D. Reimer-Tiemann reaction
259.

With anhydrous zinc chloride, ethylene glycol gives…….

A. Formaldehyde
B. Acetylene
C. Acetaldehyde
D. Acetone
Answer» D. Acetone
260.

Gasoline is the name of ……………

A. Crude oil
B. The gaseous constituents of petroleum
C. The mixture of uncondensed gases produced in the distillation of crude oil
D. The mixture of the residue and gas oil obtained in the distillation of crude oil
Answer» C. The mixture of uncondensed gases produced in the distillation of crude oil
261.

The oxidation of benzyl chloride with lead nitrate gives……………

A. Benzyl alcohol
B. Benzoic acid
C. Benzaldehyde
D. p –chlorobenzaldehyde
Answer» D. p –chlorobenzaldehyde
262.

In reaction of alcohols with alkali metal, acid etc. which of the following alcohol will react fastest….

A. Secondary
B. Tertiary
C. Primary
D. All equal
Answer» D. All equal
263.

The reagent with which both aldehyde and acetone react easily is…………….

A. Fehling's reagent
B. Grignard reagent
C. Schiff's reagent
D. Tollen's reagent
Answer» C. Schiff's reagent
264.

Acetaldehyde reacts with C2H5 MgCl the final product is…………

A. An aldehyde
B. A ketone
C. A primary alcohol
D. A secondary alcohol
Answer» E.
265.

In the commercial gasolines, the type of hydrocarbons which are more desirable is………..

A. Branched hydrocarbon
B. Straight-chain hydrocarbon
C. Linear unsaturated hydrocarbon
D. Toluene
Answer» B. Straight-chain hydrocarbon
266.

Which of the following compounds does not contain an -OH group………..

A. Phenol
B. Carboxylic acid
C. Aldehydes
D. Alcohols
Answer» D. Alcohols
267.

Octane number has 0 value for……….

A. iso-octane
B. n-hexane
C. n-heptane
D. iso-heptane
Answer» D. iso-heptane
268.

Which gives CH4 when treated with water……..

A. Silicon carbide
B. Calcium carbide
C. Aluminium carbide
D. Iron carbide
Answer» D. Iron carbide
269.

A compound, containing only carbon, hydrogen and oxygen, has a molecular weight of 44. Oncomplete oxidation it is converted into a compound of molecular weight 60. The original compound is ?

A. An aldehyde
B. An acid
C. An alcohol
D. an ether
Answer» B. An acid
270.

Chloral is………..

A. CCl3CHO
B. CCl3COCCH3
C. CCl3COCCl3
D. CCl3CH2OH
Answer» D. CCl3CH2OH
271.

Which of the following fractions of petroleum refining contains kerosene ? (Boiling ranges in o C aregiven below)

A. 40 – 80
B. 80 - 200
C. 200 - 300
D. Above 300
Answer» D. Above 300
272.

Which of the following compounds is insoluble even in hot concentrated H2SO4………

A. Ethylene
B. Benzene
C. Hexane
D. Aniline
Answer» D. Aniline
273.

Which of the following is not characteristic of alcohols……

A. They are lighter than water
B. Their boiling points rise fairly uniformly with increasing molecular weight
C. Lower members are insoluble in water and organic solvents but solubility regularly increases with molecular weight
D. Lower members have pleasant smell and burning taste, while higher members are odourless and tasteless
Answer» D. Lower members have pleasant smell and burning taste, while higher members are odourless and tasteless
274.

Which of the following has maximum boiling point……………

A. iso-octane
B. n-octane
C. 2, 2, 3, 3-tetramethyl butane
D. n-butane
Answer» C. 2, 2, 3, 3-tetramethyl butane
275.

Which represents an alkane………

A. C5H8
B. C6H8
C. C9H10
D. C7H16
Answer» E.
276.

The preparation of ethane by electrolysis of aqueous solution of potassium acetate is called as…….

A. Wurtz reaction
B. Sabatier-Senderen's reaction
C. Kolbe's synthesis
D. Grignard reaction
Answer» D. Grignard reaction
277.

Propane is obtained from propene, by which of the following methods……….

A. Wurtz reaction
B. Dehydrogenation
C. Frankland reaction
D. Catalytic hydrogenation
Answer» B. Dehydrogenation
278.

At 530 K , glycerol reacts with oxalic acid to produce …….

A. Allyl alcohol
B. Formic acid
C. Glyceraldehyde
D. Glycerol monooxalate
Answer» B. Formic acid
279.

Which is used as an antifreeze…….

A. Glycol
B. Ethyl alcohol
C. Water
D. Methanol
Answer» B. Ethyl alcohol
280.

To distinguish between formaldehyde and acetaldehyde, we require……….

A. Tollen's reagent
B. Fehling's solution
C. Schiff's reagent
D. Caustic soda solution
Answer» E.
281.

Aldol condensation of acetaldehyde involves the formation of which of the following intermediate?

A. Acetate ion
B. A carbanion
C. A carbonium ion
D. A free radical
Answer» C. A carbonium ion
282.

Which of the following has highest percentage of hydrogen………..

A. CH4
B. C2H4
C. C6H6
D. C2H2
Answer» B. C2H4
283.

CH3 CO CH3 can be obtained by ………..

A. Heating acetaldehyde with methanol
B. Oxidation of propyl alcohol
C. Oxidation of isopropyl alcohol
D. Reduction of propionic acid
Answer» D. Reduction of propionic acid
284.

CH4 is formed when………….

A. Sodium acetate is heated with sodalime
B. Iodomethane is reduced
C. Aluminium carbide reacts with water
D. All of these
Answer» E.
285.

IUPAC name of CH3COCH3 is………..

A. Acetone
B. 2-propanone
C. Dimethyl ketone
D. Propanal
Answer» C. Dimethyl ketone
286.

Aldehydes are isomeric with………..

A. Ketones
B. Ethers
C. Alcohols
D. Fatty acids
Answer» B. Ethers
287.

Halogenation of alkanes is an example of………..

A. Electrophilic substitution
B. Nucleophilic substitution
C. Free-radical substitution
D. Oxidation
Answer» D. Oxidation
288.

A reaction between methyl magnesium bromide and ethyl alcohol gives……….

A. Methane
B. Ethane
C. Propane
D. Butane
Answer» B. Ethane
289.

Acetaldehyde reacts with ……………

A. Electrophiles only
B. Nucleophiles only
C. Free radicals only
D. Both electrophiles and nucleophiles
Answer» C. Free radicals only
290.

Which of the following is not linked with methane………….

A. Marsh gas
B. Natural gas
C. Producer gas
D. Coal gas
Answer» D. Coal gas
291.

Which one of the following compounds is prepared in the laboratory from benzene by a substitutionreaction………

A. Glyoxal
B. Cyclohexane
C. Acetophenone
D. Hexabromo cyclohexane
Answer» D. Hexabromo cyclohexane
292.

Which is the best antiknock compound or Which one of the following substances is used as anantiknock compound ……………

A. Lead tetrachloride
B. Lead acetate
C. Zinc ethyl
D. Tetraethyl lead (TEL)
Answer» E.
293.

Acetophenone is prepared from

A. Rosenmund reaction
B. Sandmayer reaction
C. Wurtz reaction
D. Friedel craft reaction
Answer» E.
294.

Acetaldehyde cannot show …………….

A. Iodoform test
B. Lucas test
C. Benedict's test
D. Tollen's test
Answer» C. Benedict's test
295.

Sodium ethoxide is a specific reagent for……………

A. Dehydration
B. Dehydrogenation
C. Dehydrohalogenation
D. Dehalogenation
Answer» D. Dehalogenation
296.

General formula of primary alcohol is …….

A. CHOH
B. COH
C. CH2OH
D. COHOH
Answer» D. COHOH
297.

Isomerism in saturated hydrocarbons is due to…………..

A. Change in the valence of carbon
B. Change in the ratio of elements in compounds
C. Formation of branches in the chain of C atoms
D. Formation of double bond
Answer» D. Formation of double bond
298.

Aldol condensation will not be observed in……….

A. Chloral
B. Phenyl acetaldehyde
C. Hexanal
D. Ethanol
Answer» B. Phenyl acetaldehyde
299.

The inorganic origin of petroleum is indicated by the fact that…………..

A. Its constituents can be separated by fractional distillation
B. Carbon and hydrocarbon can combine by absorption of solar energy to give hydrocarbons
C. Petroleum contains traces of chlorophyll
D. Oil fields are located with the help of seismograph
Answer» C. Petroleum contains traces of chlorophyll
300.

Haloform test is given by the following substance……………

A. HCHO
B. (CH3)2 CO
C. CH3OCH3
D. CH3CH2Cl
Answer» C. CH3OCH3