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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.
| 251. |
With cold and dilute sodium hydroxide fluorine reacts to giveA. `NaF and OF_(2)`B. `NaF+O_(3)`C. `O_(2) and O_3 `D. `NaF+O_2` |
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Answer» Correct Answer - A `F_(2)` on reaction with NaOH give different products under different conditions. `2F_(2)+2NaOH("Cold")("dil") to 2NaF+H_(2)O+OF_(2)` `4F_(2)+NaOH("hot")("dil") to 4NaF+2H_(2)O+O_(2)` |
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| 252. |
The correct order of reactivity of halogens isA. `F gt Cl gt Br gt I `B. `F lt Cl gt Br lt I `C. `F lt Cl lt Br lt I `D. `F lt Cl lt Br gt I ` |
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Answer» Correct Answer - A The atomic number of fluorine (F), Chlorine (Cl), bromine (Br) and Iodine(I) are 9,17 ,35 and 53 respectively . Therefore , the correct order of reactivity of halogens is `F gt Cl gt Br gt I. ` |
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| 253. |
The shape of `IF_7` molecule isA. pentagonal bipyramidalB. trigonal bipyramidalC. tetrahedralD. octahedral |
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Answer» Correct Answer - A The shape of `IF_(7)` molecules is pentagonal bipyramidal. Its hybridisation is `sp^(3)d^(3)` due to the presence of seven bond pairs and zero lone pair of electrons. |
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| 254. |
The structure of `IF_7` isA. Trigonal bipyramidB. OctahedralC. Pentagonal bipyramidD. square pyramid |
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Answer» Correct Answer - C In `IF_7`, I undergoes `sp^3d^3` hybridisation |
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| 255. |
Unlike ordinary fire thermite fire cannot be stopped pouring water. Explain . |
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Answer» In ordinary fire, the water not only decreases the temperature of the burning material, it also cuts off the supply of `O_(2)`. However in thermite reaction. `2Al + Fe_(2)O_(3) overset("Heat")rarr Al_(2)O_(3) + 2Fe` the oxygen needed for reaction is supplied by the metal oxide (i.e, `Al_(2)O_(3)`), therefore cutting off the supply of atomospheric oxyge has no effect. Further, at high temperature (around `1270-1300 K`), Al reacts with `H_(2)O` to produce `H_(2)O` to produce `H_(2)` gas which helps to spread rather than extinguishing the fire. `2Al + 3H_(2)O overset(11270-1300K)rarr Al_(2)O_(3) + 3H_(2)` |
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| 256. |
The substance used in holmes singnals of the ship is a mixture of :A. `CaC_(2)+Ca_3P_2`B. `Ca_3(PO_4)_2+Pb_3O_4`C. `H_3PO_4+CaCl_2`D. `NH_3+HOCl` |
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Answer» Correct Answer - 1 |
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| 257. |
Which of the following oxides is not expected to react with sodium hydroxide ?A. CaOB. SiOC. BeOD. `B_(2)O_(3)` |
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Answer» Correct Answer - A `BeO` is amphoteric, `B_(2)O_(3)` and `SiO_(2)` are acidic while `CaO` is basic. Therefore, `CaO` will not react with alkali. |
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| 258. |
In which of the following arrangements, the given sequence is not strictly according to the property indicated against it ?A. `HF lt HCl lt HBr lt HI` : increasing acidie strengthB. `H_(2)O lt H_(2)S lt H_(2)Se lt H_(2)Te`: increasing `pK_(a)` valuesC. `NH_(3) lt PH_(3) lt AsH_(3) lt SbH_(3)` : increasing acidic characterD. `CO_(2) lt SiO_(2) lt SnO_(2) lt PbO_(2)` : increasing oxidising power |
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Answer» Correct Answer - B Acidity increases or `pK_(a)` the `H-M` bond strength decreases from O to Te. Thus, option (b) is not correct. |
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| 259. |
The noble gas which can diffuse through rubber and glass easily isA. XeB. NeC. ArD. He |
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Answer» Correct Answer - D Helium has an unusual property of diffusing through commonly used laboratory material such as rubber and glass. |
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| 260. |
Argon was discovered byA. ReyleighB. RamsayC. Both (a) and (b)D. Frankland and Lockeyer |
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Answer» Correct Answer - C Argon was discovered by both Rayleigh and Ramsay . |
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| 261. |
The noble gas was first time discovered byA. CavendishB. William RamsayC. RayleighD. Frankland |
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Answer» Correct Answer - B William Ram say was the scientist who discovered noble gas first time . |
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| 262. |
Asseration: Iodine does not displace `Cl_(2)` or `Br_(2)` from their chlorides and bromides but displace them from their oxo-salts. Reason: `E_(op)^(@)" of "I_(2)gtE_(OP)^(@)" of "Cl_(2) " or "Br_(2)`A. If both asseration and reson are true and the reason is the correct explanation of the asseration.B. If both asseration and reason are true ans the reason is the correct explanation of the asseration.C. If asseration is true but reason is false.D. If asseration is false but reason is true. |
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Answer» Correct Answer - B `2HClO_(3)+I_(2)to2KO_(3)+Cl_(2)` `KCl+I_(2)to"No reaction"toE_(OP)^(@)` of `ClltE_(OP)^(@)`of `I`, Thus, `I` will oxidise and `Cl` will reduce. |
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| 263. |
Asseration: Liquid `I_(2)` conducts current very slightly. Reason: Iodine in liquid state show partial auto ionisation.A. If both asseration and reson are true and the reason is the correct explanation of the asseration.B. If both asseration and reason are true ans the reason is the correct explanation of the asseration.C. If asseration is true but reason is false.D. If asseration is false but reason is true. |
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Answer» Correct Answer - A ` 3l_(2(l)) harr I^(3+) +I_(3)^(-)` |
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| 264. |
The noble gas which was discovered first in the sun and then on the earthA. ArB. XeC. NeD. He |
| Answer» Correct Answer - D | |
| 265. |
Asseration: Iodine is sparingly soluble in water but fairly soluble in `KI`. Reason: Iodine is non-polar in nature.A. If both assertion and reason are true and reason is the true explanation of the asseraton.B. If both asseration and reason are true but the reason is not the correct explanation of asseration.C. If the asseration is true but reason is false.D. If asseration is false but reason is true. |
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Answer» Correct Answer - B Iodine is more soluble in `KI` due to complex `(KI_(3))` formation. |
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| 266. |
Which noble gas is more soluble in water ?A. `He`B. `Ar`C. `Ne`D. `Xe` |
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Answer» Correct Answer - D The solubility of noble gases increase with increase in molar mass due to increase in van der Waals forces. However, these are sparingly soluble. |
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| 267. |
Noble gases are sparingly soluble in water due toA. Dipole - dipole interactionsB. Dipole - induced dipole interactionsC. Induced dipole - induced dipole interactionsD. Hydrogen bondings |
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Answer» Correct Answer - B Water is polar molecule . It induces polarity in inert gas atom leading to dipole-induced dipole interaction. |
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| 268. |
Which of the following halides is least statbled and has doubtful existence?A. `Cl_(4)`B. `Gel_(4)`C. `Snl_(4)`D. `PbI_(4)` |
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Answer» Correct Answer - D `Pbl_(4)` is least stable because of two reasons (1) size of iodine is biggest (2) oxidation state of `pb` is more statble than state because of inert pair effect. |
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| 269. |
Reaction of `PCl_(3)` and PhMgBr would giveA. bromobenzeneB. chlorobenzeneC. triphenylphosphineD. dichlorobenzene |
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Answer» Correct Answer - C `3PhMgBr+PCl_(3)toPh_(3)P+3MgBrCl` |
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| 270. |
The coordination number of `AlCl_(3)` in their solid, solid liquid and gaseous state is respectively :A. 6,6,4B. 6,4,4C. 6,6,6D. 4,4,4 |
| Answer» Correct Answer - B | |
| 271. |
Select the pair of molecules in which bond angle of both molecules are not same :A. `BCl_(3),BF_(3)`B. `SiCl_(4),C Cl_(4)`C. `PCl_(5),PBr_(5)`D. `NF_(3),PF_(3)` |
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Answer» Correct Answer - D (A),(B)& (C ) have regular geometry so they have a definate bond angle |
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| 272. |
In which of the following hybridisation state of the central atom would be changed if transformed from monomeric to dimeric or polymeric species. `BeCl_(2)(g)toBeCl_(2)(s)`, `AlCl_(3)(g)toAl_(2)Cl_(6)(l)` `BeH_(2)(g)toBeH_(2)(s)`, `ICl_(3)(g)toI_(2)Cl_(6)`A. `sp^(2)` to `sp^(3)`B. sp to `sp^(3)`C. `sp^(3)d` to `sp^(3)d^(2)`D. All of the above |
| Answer» Correct Answer - D | |
| 273. |
On heating with carbon, which of the following elements donot from carbides?A. BB. AlC. InD. Ga |
| Answer» Electrons are spread (delocalised) between the structure. | |
| 274. |
Why is `C Cl_(4)` used in fire extinguishers while `CS_(2)` cannot be used? |
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Answer» `C Cl_(4)` is a heavy non-combustible liquid. When its vapour are sprayed on fire, they form and envelope arround fire and donot allow the air to come in its contact. Therefore `C Cl_(4)` is used at a fire extinguisher under the name pyrene. `CS_(2)` is a highly combustible liquid and, thus, cannot be used a fire extinguisher. `CS_(2)+3O_(2)rarrCO_(2)+2SO_(2)` |
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| 275. |
`CS_(2)` reacts with `Cl_(2)` to produce:A. `C Cl_(4)` and `S_(2)Cl_(2)`B. `C Cl_(2)` and `SCl_(4)`C. `C Cl_(4)` and `SCl_(2)`D. `C Cl_(4)` and `SCl_(6)` |
| Answer» Correct Answer - A | |
| 276. |
(a) Number of ions which are regarded as ionic carbides amongst `(C^(4-),C_(2)^(2-),C_(3)^(4-),C_(4)^(3-))=X` (b) When oxalic acid is heated with conc. `H_(2)SO_(4)` it produces number of different gases amongst `(CO,CO_(2),SO_(3))=Y` ( c) Number of molecules having V-shaped structure amongst `(SnCl_(2),PbCl_(2),COS)=Z` Find X+Y+Z. |
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Answer» Correct Answer - `7` `X=3,Y=2,Z=2` |
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| 277. |
How many of the following have zero dipole moment? ` C Cl_(4),,C_(2)O_(3),C_(3)O_(2),CO,CS_(2),CO_(2),,C Cl_(2),CH_(2)Cl_(2),C_(2)H_(2)` |
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Answer» Correct Answer - `0005` `C Cl_(4),C_(3)O_(2),CS_(2),CO_(2),C_(2)H_(2)` |
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| 278. |
On heating a borate with ethyl alcohol and cone. `H_(2)SO_(4)`, a green edged flame is noticed. How will you account for it? |
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Answer» Upon borate reacts with `H_(2)SO_(4)` to form boric acid `(H_(3)BO_(3))` which forms triethyl borate (ester) with ethyl alcohol the vapours formed upon heating burn with green edged flame. `H_(3)BO_(3)+3C_(2)H_(5)Ohrarr(C_(2)H_(5)O)_(3)B+3H_(2)O` |
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| 279. |
A mixture of boric acid with ethyl alcohol burns with green edged flame due to the formation ofA. Ethyle boraxB. Ethyl borateC. Methyl boraxD. Methyle borate |
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Answer» Correct Answer - B `H_(3)BO_(3)+3C_(2)H_(5)OHtoB()C_(2)H_(5))_(3)+3H_(2)O` |
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| 280. |
A mixture of boric acid with ethyl alcohol burns with green edged flame due to the formation ofA. boron trifluroidB. metaboric acidC. ethyl borateD. orthoboric acid |
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Answer» (c )`underset("Boric acid")(H_(3)BO_(3))+underset("Ethyl alchohol")(3C_(2)H_(5))overset(-3H_(2)O)tounderset("Ethyl borate")((C_(2)H_(5))_(3)BO_(3)` it burns with green edged flame. |
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| 281. |
What happens when boric acid is heated ? |
| Answer» `4H_(3)BO_(3) overset(370K)underset(-4H_(2)O)rarr 4HBO_(2) underset(-H_(2)O)overset(410 K)rarr H_(2)B_(4)O_(7) overset(" Red heat ")rarr 2B_(2)O_(3) + 4H_(3)BO_(3)` | |
| 282. |
What happens when : (i) Carbon dioxide is passed through an aqueous solution of sodium metaborate. (ii) Boric acid is heated with ethyl alcohol in presence of concentrated sulphuric acid. |
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Answer» (i) A mixture of sodium tetraborate and sodium carbonate a formed. `underset(" Sod. Metaborate ")(4NaBO_(2))+CO_(2) rarr underset(" Sod. Tetraborate ")(Na_(2)B_(4)O_(7)) + underset(" Sod. Carbonate ")(Na_(2)CO_(2))` (ii) Triethylborate is formed. `H_(3)NO_(3)+3C_(2)H_(5)OH overset("Conc." H_(2)SO_(4))rarrunderset("Triethylborate")(B(OC_(2)H_(5))_(3)) + 3H_(2)O` |
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| 283. |
Identify the correct resonance structures of carbon dioxide from the one given below:A. `O-C-=O`B. `O=C=O`C. `.^(-)O-=C-O^(+)`D. `.^(-)O-C-=O^(+)` |
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Answer» Correct Answer - B::D Both the resonating structures for `CO_(2)` are correct. |
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| 284. |
Assertion (A): If aluminium atom s replace a few silicon atoms in three dimensional network of silicon dioxide, the overall structure acquries a negative charge. Reason(R): Aluminium is trivalent while silicon is tetravalent.A. Both A and R are correct and R is the correct explanation of A.B. Both A and R are correct but R is not the correct explanation of A.C. Both A and R are not correctD. A is not correct but R is correct. |
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Answer» Correct Answer - A Reason is the correct explnation for assertion. |
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| 285. |
`S_(1):` Argon is used in arc welding of metals or alloys to provide an inert atomosphere. `S_(2):" XeF_(2),XeF_(4)` and `XeF_(6)` are colourless crystalline solids and sublime readily at `298K`. `S_(3):XeF_(2),XeF_(4)` and `XeF_(6)` are readily hydrolysed. `S_(4): ` Xenon fluorides react with flourine ion acceptor to form cationic species and fluoride ion donors to form fluoro anions.A. `F F F F `B. `T F T F`C. `T T T T`D. `F T F T ` |
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Answer» Correct Answer - C `S_(1)` and `S_(2)` are correct statements. `S_(3):2XeF_(2)(s)+H_(2)O(l)rarr2Xe(g)+4HF(aq)+O_(2)(g)` `{:(6XeF_(4)+12H_(2)O,rarr,4Xe+XeO_(3),+,24HF+3O_(2)),(XeF_(5)+3H_(2)O,rarr,XeO_(3)+6HF,,):}}"Complete hydrolysis"` `S_(4): XeF_(2)+PF_(5)rarr[XeF]^(+)[PF_(6)]^(-)` `XeF_(4)+SbF_(5)rarr[XeF_(3)]^(+)[SbF_(6)]^(-)` `XeF_(6)+MFrarr M^(+)[XeF_(7)]^(-)` `M=Na, K, Rb" or "Cs` |
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| 286. |
Statement-1 : Argon is used in the laboratory for handling substances that are air-sensitive. Statement-2 : Argon is inert towards chemical reactivity due to the completely filled valence shell electronic configuration, high ionization enthalpy and more positive electron gain enthalpy.A. Statement-1 is True, Statement-2 is True,Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True,Statement-2 is NOT a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is FalseD. Statement-1 is False, Statement-2 is True |
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Answer» Correct Answer - A |
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| 287. |
All the noble gases are colourless and tasteless monoatomic gases. In general, noble gases are least reactive and their inertness to chemical reactivity is attributed to the following reasons. Reactive and their inertness to chemical reactivity is attributed to the following reasons. (i)Except helium, all have completely filled `ns^(2)np^(6)` electronic configuration in their valence shells. (ii)All have high ionisation enthalpy and more positive electron gain enthalpy. However, a number of xenon compounds mainly with most electronegative elements like fluorine and oxygen have been synthesized under different conditions and fluorides of xenon have been used as an oxidising agent and a fluorinating agent in many of the chemical reactions The correct order of the abundance of various noble gases in air is :A. `He gt Ar gt Kr gt Ne gt Xe`B. `Ar gt Ne gt Kr gt He gt Xe`C. `Ar gt He gt Ne gt Kr gt Xe`D. `Ar gt Xe gt He gt Ne gt Kr` |
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Answer» Correct Answer - B |
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| 288. |
All the noble gases are colourless and tasteless monoatomic gases. In general, noble gases are least reactive and their inertness to chemical reactivity is attributed to the following reasons. Reactive and their inertness to chemical reactivity is attributed to the following reasons. (i)Except helium, all have completely filled `ns^(2)np^(6)` electronic configuration in their valence shells. (ii)All have high ionisation enthalpy and more positive electron gain enthalpy. However, a number of xenon compounds mainly with most electronegative elements like fluorine and oxygen have been synthesized under different conditions and fluorides of xenon have been used as an oxidising agent and a fluorinating agent in many of the chemical reactions Noble gases have very low melting and boiling points because.A. they have high ionisation enthalpyB. they have more positive electron gain enthalpyC. the type of interatomic interaction is weak metallic bonds.D. the type of interaction is weak dispersion forces. |
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Answer» Correct Answer - D |
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| 289. |
Statement-1: Noble gases are least reactive Statement-2: They have high ionisation enthalpy and more positive electron gain enthalpy.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is FalseD. Statement-1 is False, Statement-2 is True |
| Answer» Correct Answer - A | |
| 290. |
All the noble gases are colourless and tasteless monoatomic gases. In general, noble gases are least reactive and their inertness to chemical reactivity is attributed to the following reasons. Reactive and their inertness to chemical reactivity is attributed to the following reasons. (i)Except helium, all have completely filled `ns^(2)np^(6)` electronic configuration in their valence shells. (ii)All have high ionisation enthalpy and more positive electron gain enthalpy. However, a number of xenon compounds mainly with most electronegative elements like fluorine and oxygen have been synthesized under different conditions and fluorides of xenon have been used as an oxidising agent and a fluorinating agent in many of the chemical reactions Identify the correct statement with respect to `XeF_(2)`A. It is a colourless crystalline compound which sublimes at 298 KB. `BrO_(3)^(-)` being good oxidising agent cannot be oxidised by `XeF_(2)` to `BrO_(4)^(-)`C. It undergoes hydrolysis more rapidly with alkali in comparison to water.D. `XeF_(2)` can be prepared by heating Xenon with `O_(2)F_(2)` at `118^(@)C` |
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Answer» Correct Answer - B |
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| 291. |
Which of the noble gases is the least polarized?A. `Xe`B. `Ar`C. `Ne`D. `He` |
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Answer» Correct Answer - D He is least polarizable because of small atomic size. |
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| 292. |
On addition of conc. `H_(2)SO_(4)` to a chloride salt, colourless fumes are evolved but in case of iodide salt, violet fumes come out. This is becauseA. `H_(2)SO_(4)` reduces HI to `I_(2)`B. HI is of violet colourC. HI gets oxidised to `I_(2)`D. HI changes to `HIO_(3)` |
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Answer» Correct Answer - C Hydrogen iodide (HI) is more stronger oxidising agent than `H_(2)SO_(4)` . So , it reduces `H_(2)SO_(4)` to `SO_(2)` and itself oxidises to `I_(2)`. Is violet hence in adding conc. `H_(2)SO_(4)` to HI, it gets oxidised to `I_(2)`. `H_(2)SO_(4)+2HItounderset(("Violet colour"))(SO_(2)+I_(2)+2H_(2)O)` |
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| 293. |
Asseration: Ammonia and water are electron rich hydrides. Reason: They have electrons more than required for bonding.A. If both asseration and reson are true and the reason is the correct explanation of the asseration.B. If both asseration and reason are true ans the reason is the correct explanation of the asseration.C. If the asseration is true but reason is false.D. If asseration is false but reason is true. |
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Answer» Correct Answer - A Both asseration and reason are true and the reason is the correct explanation of the asseration. |
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| 294. |
Which one of the following noble gases is not found in atmoshphere?A. NeB. ArC. RnD. Kr |
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Answer» Correct Answer - D The noble gas which is not found in atmosphere is argon (Ar). |
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| 295. |
Which one of the following noble gases is not found in atmoshphere?A. `Rn`B. `Kr`C. `Ne`D. `Ar` |
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Answer» Correct Answer - A All the noble gases except radon occur in the atmosphere. Xenon and radon are the rarest elements of the group. Radon is obtain as a decay product of `226Ra`. `._(88)^(226)Ra rarr ._(86)^(222)Rn+ ._(2)^(4)He` |
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| 296. |
Asserarion: Phosphine is prepared in an inert atmoshphere of `CO_(2)` and `H_(2)`. Reason: Phosphine is highly inflammable in air.A. If both asseration and reson are true and the reason is the correct explanation of the asseration.B. If both asseration and reason are true ans the reason is the correct explanation of the asseration.C. If the asseration is true but reason is false.D. If asseration is false but reason is true. |
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Answer» Correct Answer - A Both asseration and reason are true and the reason is the correct explanation of the asseration. |
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| 297. |
Asserarion:Bleaching action action of `SO_(2)` is temporary and by reduction. Reason: The colour of material is regained due to oxidation by air.A. If both asseration and reson are true and the reason is the correct explanation of the asseration.B. If both asseration and reason are true ans the reason is the correct explanation of the asseration.C. If asseration is true but reason is false.D. If asseration is false but reason is true. |
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Answer» Correct Answer - A `SO_(2)+2H_(2)OrarrH_(2)SO_(4)+2H` Coloured matter `+Hrarr"Colour less"rarroverset(Delta)(rarr)` Coloured. |
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| 298. |
When sugar is treated with conc. sulphuric acid, the sugar is charred. In this process, sugar isA. reducedB. oxidisedC. sulphonatedD. dehydrated |
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Answer» Correct Answer - D `C_12H_22O_11 overset(conc. H_2SO_4) to 12C + 11H_2O` Dehydrating prop. Of Conc. `H_2SO_4` |
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| 299. |
Ozone is considered to beA. a resonance hybrid of oxygenB. an isomer of oxygenC. an oxide of oxygenD. an allotropic modification of oxygen |
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Answer» Correct Answer - D Ozone `O_3` is allotropic form of oxygen . Other is `O_2` |
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| 300. |
Dry `SO_2` does not bleach dry flowers becauseA. nascent hydrogen responsible for bleaching is produced only in presence of moistureB. water is the actual reducing agent responsible for bleachingC. water is stronger acid than `SO_2 `D. the OH- ions produced by water cause bleaching |
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Answer» Correct Answer - A Nascent hydrogen is produced only in presence of moisture and is responsible for bleaching. `SO_2 + H_2O to H_2SO_4 + 2 [H]` Coloured flower + [H] `to` Colourless flower |
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