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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 951. |
Why are alkanes called paraffins? |
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Answer» Paraffins means little affinity. Alkanes due to strong CC and C-H bonds are relatively chemically inert. They are thus called as paraflins. |
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| 952. |
The compound X in the reaction. A. B. C. D. |
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Answer» Correct Answer - B Since `I^(+)` is the electrophite, therefore, iodobenzene is formed. `I-Cl+AlCl_(3)rarr I^(+)+AlCl_(4)^(-)` `C_(6)H_(6)+I^(+)overset(AlCl_(4)^(-))rarr C_(6)H_(5)I+AlCl_(3)+HCl` `I-Cl+AlCl_(3)to I^(+)+AlCl_(4)^(-)` `C_(6)H_(6)+I^(+) overset(AlCl_(4)^(-))to C_(6)H_(5)O+AlCl_(3)+HCl` |
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| 953. |
The reaction fo toluenec with `Cl_(2)` in presence of `FeCl_(3)` gives prediominantlyA. benzyl chlorideB. o and p-chlorotoluenceC. m-chlorotoluenceD. benzoyl chloride |
| Answer» Correct Answer - B | |
| 954. |
The boiling points four saturated hydrocarbons are given below. Which boiling point suggests maximum number of carbon atoms in its molecule ?A. `-162 ^(@)C`B. `-88.6^(@)C`C. `-0.5 ^(@)C`D. `-42.2^(@)C` |
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Answer» Correct Answer - C The heavier the molecule, greater is the boiling point. So molecule with boiling point. `=-0.5^(@)C` will have maximum number of carbon atoms. |
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| 955. |
The hydrocarbon that reacts with ammonical cuprous chloride is-A. Essentially aromaticB. EthaneC. EthyneD. Ethene |
| Answer» Correct Answer - C | |
| 956. |
What product would be obtained from the reaction of cyclopropane with `Cl_(2)` in the presence of `FeCl_(3)`?A. 1,2-dichloropropaneB. 1,2-dichlorocyclopropaneC. 1,3-dichloropropaneD. 1,1-dichlropropane |
| Answer» Correct Answer - 3 | |
| 957. |
With ammonical cuprous chloride solution, a reddish brown precipitate is obtained on treating withA. `CH_(4)`B. `C_(2)H_(4)`C. `C_(2)H_(2)`D. `C_(3)H_(6)` |
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Answer» Correct Answer - c Acetylene forms brown copper acetylide with ammonical cuprous chloride solution. `CuCl_(2)+C_(2)H_(2)rarrCuC_(2)+2HCl` `2HCl+2NH_(4)OHrarr 2NH_(4)Cl+2H_(2)O` |
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| 958. |
Which of the following is a naphatene?A. BenzeneB. n-HexaneC. CyclohexaneD. Naphthlene. |
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Answer» Correct Answer - C Cycloalkanes are called napthenes. |
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| 959. |
The natural gas mainly containsA. methaneB. propaneC. butaneD. pentane |
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Answer» Correct Answer - a Natural gas contains mainly methane. |
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| 960. |
Assuming that no rearrangement is taking place, then how many hydrocarbons are obtained from the reaction of 2-chloropentane with isopropyl chloride in the presence of sodium. Do not include stereoisomers. |
| Answer» Correct Answer - 7 | |
| 961. |
Benzene reacts with excess of chlorine in presence of ultraviolet light to produceA. HexachlorobenzeneB. p-DichlorobenzeneC. Benzene hexachlorideD. Chlorobenzene |
| Answer» Correct Answer - C | |
| 962. |
`C_(6)H_(6)+Z overset(Anhy.AlCl_(3))to` Toluene The compound Z isA. Acetic acidB. Acetic anhydrideC. AcetoneD. Chloromethane. |
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Answer» Correct Answer - D `C_(6)H_(6)+CH_(3)-Cl underset(-HCl)overset("Anhyd.AlCl_(3))to C_(6)H_(5)-CH_(3)` |
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| 963. |
When nitrobenzene is treated with `Br_(2)` in presence of `FeBr_(3)`, the major product formed is `m-`bromo`-`nitrobenzene. Statement which is related to obtain the `m-`isomer isA. the electron density on meta-carbon is less that on ortho and para-positionsB. the intermediate carbonium ion formed after initial attack of `Br^(+)` at the meta-position is least destabilisedC. lose of aromaticity when `Br^(+)` attacks at the ortho and para-positions and not at meta-positionD. easier loss of `H^(+)` to regain aromaticity from the meta-position than from ortho and para-positions |
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Answer» Correct Answer - B `-NO_(2)` is a m-directing and deactivating group, hence `sigma`-complex is formed by attack of `Br^(+)` at meta-position will be most stable. |
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| 964. |
Methane will be produced in which of the following reaction:A. `Be_(2)Coverset(H_(2)O)to`B. `CH_(3)OHoverset(LAH)to`C. `CH_(3)-Clunderset(EtOH)overset(Na)to`D. `Al_(4)C_(3)overset(H_(2)O)to` |
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Answer» Correct Answer - A::C::D (A),(C),(D). ltBrgt `Be_(2)C+4H_(2)OtoCH_(4)+2Be(OH)_(2)` `CH_(3)-Clunderset(EtOH)overset(Na)toCH_(4)` `Al_(4)O_(3)+12H_(2)Oto3CH_(4)+4Al(OH)_(3)` |
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| 965. |
Identify the correct order of reactivity in electrophilic substitution reaction of the following compounds. (1) Benzene (2) Toluene (3) Chlorobenzene, (4) Nitrobenzene.A. `AgtBgtCgtD`B. `DgtCgtBgtA`C. `BgtAgtCgtD`D. `BgtCgtAgtD` |
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Answer» Correct Answer - c More stronger the activating group, more will be electrophilic substitution reaction. `-NO_(2)` groups is electron attraction group, so it deactivates the benzene ring largely `-Cl` atom also deactivates the benzene ring but this deactivation is lower to `-NO_(2)` group, while `-CH_(3)` GROUP ACTIVATES. |
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| 966. |
Among the following compounds, the decreasing order of reactivity towards electrophilic substitution is A. `IIIgtIgtIIgtIV`B. `IVgtIgtIIgtIII`C. `IgtIIgtIIIgtIV`D. `IIgtIgtIIIgtIV` |
| Answer» Correct Answer - A | |
| 967. |
The alkene that will give the same product with HBr in the presence as well as in the presence of peroxide isA. 2-ButeneB. 1-buteneC. propeneD. 1-hexane |
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Answer» Correct Answer - A The addition of HBr to symmetrical alkenes is not effected by the presence of absence of peroxide. |
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| 968. |
The most reactive alkene HBr among the following isA. `(CH_(3))_(2)C=C(CH_(3))_(2)`B. `CH_(2)=CH_(2)`C. `(CH_(3))_(2)=CH_(2)`D. `CH_(3)CH=CHCH_(3)` |
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Answer» Correct Answer - A `(CH_(3))_(2)C=C(CH_(3))_(2)` has the least heat of hydrogenation and also forms most stable `3^(@)` carbocation. |
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| 969. |
The dihedral angle between two C-H bonds the staggered conformation of ehtane isA. `180^@`B. `0^@`C. `120^@`D. `60^@` |
| Answer» Correct Answer - D | |
| 970. |
In which of the following compounds, the bond length between hybridised carbon atom and other carbon atom is minimum?A. ButaneB. PropyneC. PropeneD. Butene |
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Answer» Correct Answer - B We know C-C bond length = 1.5 Å that C=C bond length = 1.34 Å C-= C bond length = 1.20 Å Since, propyne has triple bond, therefore, it has minimum bond length. |
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| 971. |
Match Column I with Column II and select the correct answer from the given codes A. a-i,b-ii,c-iii,d-ivB. a-ii,b-iii,c-iv,d-iC. a-iii-b-iv,c-i,d-iiD. a-iv,b-iii,c-i,d-ii |
| Answer» Correct Answer - C | |
| 972. |
Phenylmagnesium bromide reacts with methanol to giveA. a mixture of anisole and Mg(OH)BrB. a mixture of benzene and Mg(OMe)BrC. a mixture of phenol and Mg(OMe)BrD. a mixture of toluene and Mg(OH)Br |
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Answer» Correct Answer - B `C_6overset(-delta)H_5-overset(-delta)"MgBr"+overset(delta+)H-overset(delta-)O Me to C_6H_6 + Mg(O Me)Br` |
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| 973. |
The ortho/para-directing group among the following isA. COOHB. CNC. `COCH_3`D. `NHCOCH_3` |
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Answer» Correct Answer - D Due to the presence of a lone pair of electrons on the N-atom, `-NHCOCH_3` is o, p-directing. |
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| 974. |
Aromatic hydrocarbons are highly unsaturated molecules but behave like saturated hydrocarbons. Those which contain a benzene ring are called benzenoids but those which contain some highly unsaturated ring other than benzene are called non-benzenoids. Their aromatic character can be ascertained through Hückel rule. Aromatic hydrocarbons are, however, more reactive than alkanes but are less reactive than alkenes and alkynes. The lower reactivity of arenes is because of the extra stability associated with these molecules due to delocalization of -electrons. Their stability is measured in terms of resonance energy which can be estimated from either heat of combustion or heat of hydrogenation data. They normally undergo electrophilic substitution reactions. In presence of a Lewis acid catalyst, nuclear halogenation occurs but in absence of Lewis acid catalyst and in presence of light, halogens add to the benzene ring. If an aromatic hydrocarbon contains an alkyl side chain, then in presence of heat/light side chain halogenation occurs in preference to addition of halogens to the benzene ring. The reactivity of aromatic hydrocarbons towards electrophilic substitution reactions depends upon the electron density in the benzene ring. Electron-donating groups favour while electron-withdrawing groups retard these reactions. Orientation of electrophilic substitution reactions is governed by the nature of the substituent already present in the ring. Although aromatic hydrocarbons are resistant to oxidising agents `(KMnO_4, K_2Cr_2O_7`, etc.) they do undergo ozonolysis. The enthalpy of hydrogenation of cyclohexene is `-119.5 "kJ mol"^(-1)`.If resonance energy of benzene is `-150.4 "kJ mol"^(-1)`, its enthalpy of hydrogenation would beA. `-208.1 "kJ mol"^(-1)`B. `-269.9 "kJ mol"^(-1)`C. `-358.5 "kJ mol"^(-1)`D. `-508.9 "kJ mol"^(-1)` |
| Answer» Correct Answer - A | |
| 975. |
Aromatic hydrocarbons are highly unsaturated molecules but behave like saturated hydrocarbons. Those which contain a benzene ring are called benzenoids but those which contain some highly unsaturated ring other than benzene are called non-benzenoids. Their aromatic character can be ascertained through Hückel rule. Aromatic hydrocarbons are, however, more reactive than alkanes but are less reactive than alkenes and alkynes. The lower reactivity of arenes is because of the extra stability associated with these molecules due to delocalization of -electrons. Their stability is measured in terms of resonance energy which can be estimated from either heat of combustion or heat of hydrogenation data. They normally undergo electrophilic substitution reactions. In presence of a Lewis acid catalyst, nuclear halogenation occurs but in absence of Lewis acid catalyst and in presence of light, halogens add to the benzene ring. If an aromatic hydrocarbon contains an alkyl side chain, then in presence of heat/light side chain halogenation occurs in preference to addition of halogens to the benzene ring. The reactivity of aromatic hydrocarbons towards electrophilic substitution reactions depends upon the electron density in the benzene ring. Electron-donating groups favour while electron-withdrawing groups retard these reactions. Orientation of electrophilic substitution reactions is governed by the nature of the substituent already present in the ring. Although aromatic hydrocarbons are resistant to oxidising agents `(KMnO_4, K_2Cr_2O_7`, etc.) they do undergo ozonolysis. In the reaction of `C_6H_5Y`, the major product ( gt 60%) is m-isomer , so the group Y isA. `-COOH`B. `-Cl`C. `-OH`D. `-NH_2` |
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Answer» Correct Answer - A Only -COOH is m-directing , rest are all o,p-directing. |
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| 976. |
Write IUPAC names of the following compounds: |
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Answer» (i) 2,8-Dimethyl-3, 6-decadiene, (ii) 1,3,5,7 Octatetraene, (iii) 2-n-Propylpent-1-ene, (iv) 4-Ethyl-2,6-dimethyl-dec-4-ene, |
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| 977. |
Assertion: Benzene is reactive while inorganic benzene is unreactiveReason:Inorganic benzene is borazine.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - d Inorganic benzene `(B_(3)N_(3)H_(6))` is more reactive than `C_(6)H_(6)` |
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| 978. |
Which one of the following is most reactive towards electrophilic attack?A. B. C. D. |
| Answer» Correct Answer - A | |
| 979. |
Acetylene when passed through 20% `H_(2)SO_(4)` at `80^(@)`C gives acetaldehyde. The catalyst reqruied for this conversion is:A. Anhydrous `AlCl_(3)`B. `HgSO_(4)`C. `Pd`D. `Pt` |
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Answer» Correct Answer - B `Hg^(+2)` ions works as a catlyst. |
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| 980. |
Acetylene givesA. White ppt. with ammonical `AgNO(3)` and red ppt. with ammonical `Cu(NO_(3))_(2)`B. White ppt. with ammonical `AgNO(3)` and red ppt. with ammonical `CuCl_(2)`C. White ppt. with bothD. Red ppt. with both |
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Answer» Correct Answer - B Acetylene gives white ppt. with ammonical `AgNO_(3)` and red ppt. with ammonical `CuCl_(2)` |
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| 981. |
In the reaction, `CH_(3)C-=C-CH_(3)overset((i)X)underset((ii)Zn//H_(2)O)(to)CH_(3)-underset(O)underset(||)(C)-underset(O)underset(||)(C)-CH_(3)`, X is:A. `HNO_(3)`B. `O_(2)`C. `O_(3)`D. `KMnO_(4)` |
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Answer» Correct Answer - C `O_(3)` is required |
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| 982. |
Chloroprene is used in makingA. Synthetic rubberB. PlasticC. PetrolD. All. |
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Answer» Correct Answer - A Chloroprene is used for making synthetic rubber. |
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| 983. |
Catalyst used in the dimerization of acetylene to prepare chloroprene isA. `HgSO_(4)+H_(2)SO_(4)`B. `CuCl_(2)`C. `CuCl_(2)+NH_(4)Cl`D. CuCl_(2)+NH_(3)OH` |
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Answer» Correct Answer - C `2HC-=CH underset(NH_(4)Cl)overset(Cu_(2)Cl_(2))to H_(2)=CH-C-=CH overset(HCl)to CH_(2)=CH-C-underset("Chloroprene")(underset(Cl)underset(|)(C))=CH_(2)` `overset("Polymerisation")to [-CH_(2)-CH=underset(Cl)underset(|)(C)-CH_(2)]_(n)` |
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| 984. |
Assertion (A):Among isomeric pentanes, 2,2-dimethylpentane has the highest boiling point. Reason (R): Branching does not affect the boiling point.A. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.C. Both Assertion and Reason are not correctD. Assertion is not correct but Reason is correct. |
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Answer» Correct Assertion. Among isomeric pentanes, 2,2-dimethylpentane has the lowest boiling point. Correct Reason . Branching decreases the boiling point. |
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| 985. |
Branching of hydrocaron chains results inA. increase in oxidation numberB. decrease in octane numberC. decrease in isomer numberD. increase in octane number |
| Answer» Correct Answer - D | |
| 986. |
Which of the following reagents cannot be used for the oxidation of propane?A. `KMnO_(4)/KOH`B. `C_(6)H_(5)CO_(2)OH`C. Fehling solutionD. Ozone. |
| Answer» Correct Answer - C | |
| 987. |
The product formed by the action of chlorine on ethene in saturated solution of KBr is/areA. `ClCH_(2)CH_(2)Cl+ClCH_(2)CH_(2)Br`B. `ClCH_(2)CH_(2)Cl`C. `ClCH_(2)CH_(2)Cl+BrCH_(2)CH_(2)Cl`D. `ClCH_(2)CH_(2)Cl+BrCH_(2)CH_(2)Br+ClCH_(2)CH_(2)Br` |
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Answer» Correct Answer - C `Cl_(2)+CH_(2)=CH_(2) underset(H_(2)O)overset(KBr)to Cl-CH_(2)-CH_(2)-Cl+CICH_(2)CH_(2)Br` |
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| 988. |
Ethene gas is bubbled through the water saturated with chlorine. The major product formed will beA. Ethanol chlorideB. Ethylene chlorohydrinC. Ethylene chlorideD. Ethylene glycol. |
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Answer» Correct Answer - B `H_(2)C=CH_(2)+HOCl to underset("Ethylene chlorohydrin")(underset(HO)underset(|)(H_(2)C)-underset(Cl)underset(|)(CH_(2)))` |
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| 989. |
`C_(2)H_(5)CO_(2)^(-)Na +overset(Delta)to X`. X isA. `C_(2)H_(6)` onlyB. a mixture of `C_(2)H_(4) and C_(2)H_(6)`C. `C_(2)H_(4)` onlyD. None of these |
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Answer» Correct Answer - B `C_(2)H_(5)CO^(2^(-)` on heating first forms `C_(2)H_(5)^(-)` which subsequently disproportionates. |
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| 990. |
Bromination of n-butane givesA. 1-bromobutane as the major productB. 2-bromobutane as the major productC. both 1-bromo and 2-bromobutane with equal percentageD. both 1-bromo and 2-bromo products whose percentage depends on temperature |
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Answer» Correct Answer - B Bromination of butane gives two products 1-bromobtane and 2-bromotutane since there are two different types of hydrogens in it. 2-Bromobutane is the major product. |
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| 991. |
Benzene is insoluble in ………… |
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Answer» Benzene is insoluble in water. |
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| 992. |
Benzene reacts with hydrogen in the presence of Pt to yield ………. |
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Answer» Benzene reacts with hydrogen in the presence of Pt to yield Cyclohexane. |
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| 993. |
Benzene reacts with Cl2 in the presence of sunlight to give ……….. |
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Answer» BHC (Ben.zene hexachioride) |
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| 994. |
The step in which Cl-Cl bond homolysis occurs is called ………. |
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Answer» The step in which Cl-Cl bond homolysis occurs is called Initiation step. |
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| 995. |
Electrolytic decarboxylation of sodium propionate produces?A. PropaneB. ethaneC. methaneD. butane |
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Answer» Correct Answer - D `underset("Sod. Propionate")(2H_(3)C-CH_(2))-COONa+2H_(2)O overset("Electrolysis")to ` `H_(3)C-underset("Butane")(CH_(2))-CH_(2)-CH_(3)+2NaOH+2CO_(2)+H_(2)` |
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