Free NEET Chemistry multiple-choice questions on Environmental Compounds. Attempt each question and reveal the answer with a full explanation.
Which one of the following is a Freon? CCl 2F 2 CHCl 3 C 2H 2Cl 2 C 2Cl 4 When chloroform ( CHCl 3 ) is exposed to air and light, it slowly oxidizes to form a highly poisonous gas called: Phosgene Mustard gas Tear gas Phosphine BHC (Benzene Hexachloride) is used as an insecticide under the trade name: Gammexane DDT Pyrene Freon Which polyhalogen compound is commonly used as a solvent in the manufacture of drugs and as a metal cleaning and finishing solvent? Dichloromethane Iodoform DDT Ethyl chloride Identify the compound that is used as a 'chemical shield' or for the detection of halides in the 'layer test'? CCl 4 CHCl 3 CH 2 Cl 2 C 2 H 5 Cl Which of the following possesses the highest density at room temperature? CH 2 I 2 CH 2 Cl 2 CH 2 Br 2 CHCl 3 Chloroform is stored in dark colored bottles because: It is oxidized by air in presence of light to give phosgene It is reduced by air in presence of light to give methane It reacts with the glass of the bottle in light It evaporates very quickly The organic compound 'Westron' is chemically: 1,1,2,2-tetrachloroethane Trichloroethene 1,1,1-trichloroethane Tetrachloroethene In the reaction of benzene with Cl 2 in the presence of UV light, the product formed is: Benzene hexachloride Chlorobenzene 1,2-dichlorobenzene Hexachlorobenzene Which of the following is used as a propellant in aerosols and refrigerants? CCl 2F 2 CHCl 3 CH 2Cl 2 CHI 3 Which of the following compounds is used as a paint stripper? Dichloromethane Chloroform Carbon tetrachloride Iodoform Which of the following will give a positive Beilstein test? Chlorobenzene Benzene Pyridine Urea In the process of ozone depletion, the chlorine radical acts as a: Catalyst Reactant Inhibitor Solvent What is the correct chemical formula for 'Freon-12', widely used in refrigeration? CCl 2 F 2 CHCl 3 CF 4 CH 2 F 2 Chloroform is cleaned and tested for purity using AgNO 3 solution. Pure chloroform does not give a white precipitate because: It is a covalent compound It is insoluble in water It does not contain chlorine It reacts with AgNO 3 to form a complex Which of the following is used as a fire extinguisher under the name Pyrene? CCl 4 CHCl 3 CH 2Cl 2 CH 3Cl Which of the following compounds is commonly used as a solvent for decaffeinating coffee and as a propellant in aerosols? Methylene chloride ( CH 2 Cl 2 ) Chloroform ( CHCl 3 ) Carbon tetrachloride ( CCl 4 ) Iodoform ( CHI 3 ) Exposure to high levels of which polyhalogen compound can lead to permanent damage to the liver and central nervous system, and was formerly used widely as a cleaning fluid? Carbon tetrachloride ( CCl 4 ) Methylene chloride ( CH 2 Cl 2 ) Freon-22 Iodoform ( CHI 3 ) Which of the following is formed when chloroform is treated with concentrate HNO 3 ? Chloropicrin Phosgene Tear gas Chloral Identify the number of chlorine atoms and benzene rings present in a molecule of the insecticide DDT. 5 Chlorine atoms, 2 Benzene rings 4 Chlorine atoms, 2 Benzene rings 6 Chlorine atoms, 1 Benzene ring 3 Chlorine atoms, 2 Benzene rings A small amount of 1 % ethanol is added to chloroform bottles mainly to: Convert the poisonous phosgene gas into non-toxic diethyl carbonate. Prevent the oxidation of chloroform into phosgene. Increase the anesthetic efficiency of chloroform. Act as a preservative to prevent the formation of chlorine gas. For dry cleaning of clothes instead of tetrachloroethane which is carcinogen in nature, which of the following solvents can be used? Petrol Liquid CO2 H2O2 Liquid O3 Which of the following compounds is used as a propellant in aerosols and for cleaning electronic components? Freon-11 ( CFCl 3 ) Chloroform Iodoform DDT What is the product formed when chlorobenzene reacts with chloral in the presence of concentrated H 2SO 4 ? DDT Gammexane Freon Hexachloroethane Identify the compound that will not give Iodoform test: Benzophenone Acetophenone Ethanol Isopropyl alcohol When chloroform reacts with concentrated nitric acid, it produces a liquid used as a soil sterilant and war gas known as: Chloropicrin Chlorotone Pyrene Lewisite Identify the product formed when CHI 3 is heated with silver powder. Ethyne ( C 2H 2 ) Ethene ( C 2H 4 ) Ethane ( C 2H 6 ) Methane ( CH 4 ) DDT is chemically named as: 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane p,p'-dichlorodiphenyltrichloroethane Dichloro-diphenyl-trichloroethane The compound chloral hydrate, CCl 3 CH(OH) 2 , is a rare example of a stable gem-diol. What is the reason for its stability? Intramolecular hydrogen bonding Inductive effect of three Chlorine atoms Resonance stabilization Steric hindrance The insecticide 'Mustard Gas' used in World War I is synthesized by the reaction of ethylene with: S 2Cl 2 SCl 2 Cl 2 SOCl 2 Among the following alcohols, which one will give a positive Iodoform test? Pentan-2-ol Pentan-3-ol Propan-1-ol Butan-1-ol The reaction of phenol with CCl 4 and aqueous NaOH followed by acidification gives: Salicylic acid Salicylaldehyde Chlorobenzene Benzaldehyde What is the product formed when chloroform is heated with silver powder? Ethyne Ethene Ethane Methane What is the correct IUPAC name for the insecticide commonly known as Gammaxane or Lindane? 1,2,3,4,5,6-hexachlorocyclohexane Hexachlorobenzene 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane Trichloromethane The reaction of benzoic acid with PCl 5 gives benzoyl chloride. What is the product when benzotrichloride ( C 6 H 5 CCl 3 ) is hydrolyzed in the presence of Ca(OH) 2 ? Benzoic acid Benzaldehyde Benzyl alcohol Chlorobenzene The compound which gives a yellow precipitate with I 2 /NaOH but does not react with Schiff's reagent is: Acetone Acetaldehyde Ethanol Benzaldehyde The reactive species in the Reimer-Tiemann reaction of phenol with CHCl 3 /KOH is: Dichlorocarbene ( :CCl 2 ) Trichloromethyl anion ( CCl 3 - ) Chloronium ion ( Cl + ) Formyl cation ( CHO + ) Which of the following statements about 'Halothane' ( CF 3 CHBrCl ) is correct? It is used as an inhalation anesthetic It is a major component of fire extinguishers It is used in the manufacture of Teflon It is the primary cause of the greenhouse effect Which of the following is the most effective reagent for the conversion of CCl 4 to CCl 2 F 2 (Freon-12)? SbF 3 in the presence of SbCl 5 HF gas at room temperature NaF in aqueous solution CaF 2 powder Chloroform is a polyhalogen compound. Which of the following statements regarding its physiological effects is false? It is used as a highly safe and common anesthetic in modern surgery. Inhaling its vapors depresses the central nervous system. Chronic exposure can cause damage to the liver and kidneys. It is metabolized to phosgene in the body. In the presence of an oxidant like HIO 3 or HNO 3 , the iodination of benzene with I 2 proceeds forward because: The oxidant removes HI by oxidizing it to I 2 . The oxidant acts as a catalyst for electrophilic attack. The oxidant reduces the activation energy of the reaction. Iodine becomes more nucleophilic in the presence of an oxidant. The correct order of density for the following liquid compounds at room temperature is: CCl 4 > CHCl 3 > CH 2 Cl 2 > H 2 O H 2 O > CH 2 Cl 2 > CHCl 3 > CCl 4 CCl 4 > CH 2 Cl 2 > CHCl 3 > H 2 O CH 2 Cl 2 > CHCl 3 > CCl 4 > H 2 O The reaction of chloroform with acetone in the presence of KOH yields: Chloretone Chloral Chloroformic acid Acetone hydrate Trichloroacetaldehyde, CCl3CHO reacts with chlorobenzene in presence of sulphuric acid and produces - What is the product formed when Chloroform reacts with Aniline and alcoholic KOH ? Phenyl isocyanide Benzonitrile Chlorobenzene Nitrobenzene Reaction of acetone with chloroform in the presence of KOH gives: Chloretone Chloral Chloroform Acetic acid The intermediate formed in the reaction of chloroform with KOH during the Carbylamine reaction is: Dichlorocarbene ( :CCl 2 ) Trichloromethyl radical Trichloromethyl anion Dichloromethyl cation The radical species involved in the Hunsdiecker reaction is: Carboxyl radical ( RCOO ) Carbocation ( R + ) Carbanion ( R - ) Nitrene In the nomenclature of Freons, what does the number in 'Freon-11' represent based on the C-1, H+1, F rule? CCl 3 F CCl 2 F 2 CClF 3 CF 4 Which of the following is the major product of the reaction between toluene and Cl 2 in the presence of sunlight at high temperature? Benzotrichloride Benzyl chloride Benzal chloride o-Chlorotoluene What is the correct chemical formula for Freon-113? C 2 F 3 Cl 3 CF 2 Cl 2 C 2 F 2 Cl 4 CFCl 3 Which of the following compounds is 'Halon-1301', used as a fire suppressant in sensitive areas? CF 3 Br CF 2 Cl 2 CFCl 3 C 2 F 4 Br 2 The reaction RCOOAg + Br 2 CCl 4 RBr + AgBr + CO 2 is known as: Hunsdiecker reaction Wurtz reaction Fittig reaction Etard reaction The antiseptic action of Iodoform is due to: Liberation of free iodine Its characteristic smell The iodoform molecule itself None of these Chlorofluorocarbons (CFCs) are responsible for ozone depletion because they release: Chlorine free radicals Fluorine free radicals Chlorine molecules Carbon monoxide DDT is an organochlorine compound that was widely used as an: Insecticide Antiseptic Anaesthetic Solvent