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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.
| 451. |
Hybridisation of carbon atoms in diamond isA. `sp^(3)` hybridisationB. `sp` hybridisationC. `sp^(2)` hybridisationD. `sp^(3)d^(2)` hybridisation |
| Answer» Correct Answer - A | |
| 452. |
Which of the following elements exhibit maximum number of allotropes ?A. TinB. GermaniumC. SiliconD. Lead |
| Answer» Correct Answer - A | |
| 453. |
`underset(" hot, conc.")(NaOH+Cl_(2)) to` |
| Answer» `underset(("hot and conc."))(6NaOH)+Cl_(2) to NaClO_(3)+5NaCl +3H_(2)O` | |
| 454. |
`XeF_(4)+O_(2)F_(2) to` |
| Answer» `XeF_(4)+O_(2)F to XeF_(6)+O_(2)` | |
| 455. |
name two form of graphite. |
| Answer» `alpha and beta` graphite. | |
| 456. |
Give correct order of increasing first ionization energy in carbon family. |
| Answer» Correct Answer - CgtSigtGegtPbgtSn | |
| 457. |
Noble gases were considered inert before 1962. Prior to this, Bartlett and Lohmann had previously used the highly ionization energy of `O_(2)` is `1165 " kJ mol"^(-1)`, which is almost the same as the value of `IE_(1)` for Xe `(1170 " kJ mol"^(-1))` . Experiments showed that when deep red `PtE_(6)` vapours were mixed with an equal volume of Xe, the gases combined immediately at room temperature to produce a yellow solid. Soon after this, it was found that Xe and F react directly to give Xe-fluorides. Choose the correct answer : The hybridisation state of Xe in `XeOF_(4)` is :A. `sp^(3)`B. `sp^(3)d`C. `dsp^(2)`D. `sp^(3) d^(2)` |
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Answer» Correct Answer - D Xe atom in `XeOF_(4) " is " sp^(3)d^(2)` hybridised. |
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| 458. |
On moving down the group in carbon family stability of group oxidation state +4 decreases why? |
| Answer» Due to inert pair effect. | |
| 459. |
Sodium reacts with liquids `NH_(3)` to produce.A. `NaNH_(2)` and `N_(2)`B. `NaNH_(2)` and `N_(2)`C. `NaH` and `N_(2)H_(4)`D. `NaNH_(2)` |
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Answer» Correct Answer - 2 Ammonia when passed over melten sodium or potassium metal at `575K` forms corresponding amide with the liberation of dihydrogen: `2Na+2NH_(3)overset(575K)rarr2NaNH_(2)+H_(2)` |
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| 460. |
The stability of `+1` oxidation state increases in the sequence :A. `Ga lt In lt Al lt Tl`B. `Al lt Ga lt In lt Tl`C. `Tl lt In lt Ga lt Al`D. `In lt Tl lt Ga lt Al` |
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Answer» Correct Answer - B Due to inert pair effect, `Ga, In`, and `Tl` exhibit `+1` as well as `+3` oxidation states. The stability of `+1` increases on moving down the group. `B` shows only `+3` oxidation state while for `Al, +1` state is unstable. The `+1` oxidation state is the most stable for `Tl`. |
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| 461. |
The ions `ClO^(-), ClO_(2)^(-), ClO_(3)^(-)` and `ClO_(4)^(-)` are stabilized by strongA. `ppi-ppi` bondingB. `dpi-ppi` bondingC. `ppi-dpi` bondingD. `spi-ppi` bonding |
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Answer» Correct Answer - 3 Chlorine forms a series of ocyacids and oxyanions for each of its positive odd oxidation states forms `+1,` to `+7`. The shpes fo the ions (and releated acids are based on a tetrahedral arrangment (`sp^(2)` hydridization ) around the `CI` atom. The short chlorine -oxygen bonds in each of the ions indicate that multiple bonding must be present possibily involving some contribution to the `pi` bonding by the full `p` orbitals on the oxygen atoms and empty `d` orbials on the `CI` atoms . |
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| 462. |
Which of the following compounds is used in the industry for bleaching cotton fabrics?A. `NaOCI`B. `NaCIO_(2)`C. `NaCIO_(3)`D. `NaCIO_(4)` |
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Answer» Correct Answer - 1 Sodium hyprochlorite (the most important salt of `HOCI`) is used extensively for bleaching and decolouixzation of wood pulp and textiles (cotton fabrics) and as a domestic or household bleaching . It is produced commercially by electrolysing and stirring vigorously brine solution .During electrolysis `H_(2)(g)` is liberated is cathode: `2H_(2)O+2e^(-)rarrH_(2)(g)+2OH^(-)(aq.)` This increase the concentration of `OH^(-)` in the solution. The stirring mixes the `CI_(2)` formed at the anode with the `OH^(-)` so they can react together: Anode: `2CI^(-)(aq.)rarrCI_(2)+2e^(-)` ` CI_(2)+2OH^(-)(aq.)rarrOCI^(-)(aq.)+CI^(-)(aq)+H_(2)O(l)` |
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| 463. |
Which of the following is most thermally stable?A. `HClO`B. `HCIO_(2)`C. `HCIO_(3)`D. `HCIO_(4)` |
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Answer» Correct Answer - 4 Thermal stability increases with the increase in the number of oxygen atoms due to increase in the number of bonds. `HCIO lt HCIO_(2) lt HCIO_(3) lt HCIO_(4)` As a result oxidizing power increases in the reverse order: `HClO gt HClO_(2) gt HClO_(3) gt HClO_(4)` thus, `HClO` is the strongest oxidizing agent. |
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| 464. |
The correct order of thermal stability of hydrogen halides (H-X) is :A. `HI gt HBr gt HCl gt HF`B. `HF gt HCl gt HBr gt HI`C. `HCl lt HF gt HBr gt HI`D. `HI gt HCl lt HF gt HBr`. |
| Answer» Correct Answer - B | |
| 465. |
Which of the following is not the correct order of thermal stability?A. `HOCI gt HOBR gt HOI`B. `HCIO_(2) gt HBrO_(2) gt HIO_(2)`C. `HCIO_(2) gt HBrO_(2) gt HIO_(3)`D. `HClO_(4) gt HBrO_(4) gt HIO_(4)` |
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Answer» Correct Answer - 3 Oxoacids become increasingly themally unstable with increasing size of the halogen in contrast iodic acid `(HIO_(3))` is reasonable stable while `HCIO_(3)` and `HBrO_(3)` are not very stable . |
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| 466. |
White phosphorus is kept underA. waterB. Kerosene oilC. ethanolD. conc. `HNO_(3)` |
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Answer» Correct Answer - 1 The pure from is white but attains yellow colour on long standing due to the formation of a thin film of the red variety on the surface. If has characteristic garlic smell and is very poisonous in nature. Its vapours are also injurious. Persons working with phosphrous develops a disease in which the jaw bones decay,this desease is known as Phossy jaw. when exposed to the air ,white phosphorous emits a greenish glow which is visible in the dark in the dark, a phenomenon known as Phosphrous. The effect can be used to detect the presence of white phosphorus. Because of its reactivity with oxygen ,white phospherous is stored under water ,in which it is insoluble. Bone ash glows in the dark because it ocntain white `P` which undergoes show combustiob in constact with air ,producing light. (Chemiluminescence). |
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| 467. |
The structure of white phosphorus isA. square planarB. pyramidalC. tetrahedralD. trigonal planar |
| Answer» Correct Answer - C | |
| 468. |
Oxidation state of `P` in `H_(4)P_(2)O_(5), H_(4)P_(2)O_(6), H_(4)P_(2)O_(7)` are respectivelyA. `+3,+4,+5`B. `+3,+5,+4`C. `+5,+3,+4`D. `+5,+4,+3` |
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Answer» Correct Answer - 1 `underset("Pyrophosphoric acid")(HO-underset(O)underset(||)overset(H)overset(|)(P)-O-underset(O)underset(||)overset(H)overset(|)(P)-OH)` `H_(4)P_(2)O_(7) : 4(+1)+2(X)+7(-2)=0` `X=+3` `underset("Hypophosphoric acid")(HO-underset(OH)underset(|)overset(O)overset(||)(P)-underset(OH)underset(|)overset(O)overset(||)(P)-OH)` `H_(4)P_(2)O_(6) : 4(+1)+2(X)+6(-2)=0` `X=+4` `underset("Pyrophosphoric acid")(HO-underset(OH)underset(|)overset(O)overset(||)(P)-O-underset(OH)underset(|)overset(O)overset(||)(P)-OH)` `H_(4)P_(2)O_(7) : 4(+1)+2(X)+7(-2)=0` `X=+5` this question can also be credited to redox reactions part 1 |
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| 469. |
In which one of the following species , the central atom has the tuype of hybdridiztion which is not the same as that present in other three?A. `PCl_(5)`B. `SF_(4)`C. `I_(3)^(-)`D. `SbCI_(5)^(2-)` |
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Answer» Correct Answer - 4 It has `sp^(3) d^(2)` hybridization while all othe rhave `sp^(3) d` hybridization `|{:("Species","Steric Number","Hybridization"),(PCl_(5),5+0,sp^(3) d),(SF_(4),4+1,sp^(3) d),(I_(3)^(-),2+3,sp^(3) d),(SbCl_(5)^(2-),5+1,sp^(3) d^(2)):}|` |
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| 470. |
In which one of the following species , the central atom has the tuype of hybdridiztion which is not the same as that present in other three?A. `SF_(4)`B. `I_(3)^(-)`C. `SbCl_(5)^(2-)`D. `PCl_(5)` |
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Answer» Correct Answer - B `SF_(4), H=(1)/(2)(+4-0+0)=5(sp^(3)d)` `I_(3)^(-) , H=(1)/(2)(7+2-0+3)=6(sp^(3)d^(2))` `(SbCl_(5))^(2-),H=(1)/(2)(5+5-0+2)=5(sp^(3)d)` `PCl_(5) , H=(1)/(2) (5+5-0+0)=5 (sp^(3)d)` `therefore` (b) is the correct answer. |
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| 471. |
The symbol of element with atomic number 113, isA. NhB. NiC. NoD. Nb |
| Answer» Correct Answer - A | |
| 472. |
Which of the following is not the ore of aluminium?A. BauxiteB. CryoliteC. KerniteD. Corundum |
| Answer» Correct Answer - C | |
| 473. |
The principal ore of lead isA. galenaB. anglesiteC. cerussiteD. None of these. |
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Answer» Correct Answer - A Galena, natural lead `(II)` sulphide, `PbS`, is the principal ore of lead. It is a heavy crystalline mineral of metallic appearance. It is use as a semiconductor in crystal rectifiers. Anglesite `(PbSO_(4))` and cerussite `(PbCO_(3))` are less important ores of lead. There are two methods of extracting the element : (i) Roast in air to give `PbO` and then reduce with coke or `CO` in a blast furnace: `PbS+3O_(2)overset(Delta)rarrSO_(2)+2PbOoverset(+C)rarr2Pb(l)+CO_(2)(g)` (ii) `Pbs` is partially oxidized by heating and blowing air through it. After sometime, the air is turned off and heating is continued, and the mixture undergoes self-reduction. `3PbSunderset("Air")overset(Delta)rarrPbS+2PbOunderset("Without air")overset(Delta)rarr3Pb(l)+SO_(2)(g)` |
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| 474. |
Quartz is a/anA. orthosilicateB. pyrosilicateC. sheet silicateD. three-dimensional silicate |
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Answer» Correct Answer - D Three-dimensional silicates are formed when all the four corners of a `SiO_(4)^(4-)` tetrahedron are shared. The result is a three-dimensional lattice of formula `SiO_(2)`. Examples include quartz, tridymite, and cristobalite. |
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| 475. |
Butter of tin isA. `SnCl_(2).5H_(2)O`B. `SnCl_(2).2H_(2)O`C. `SnCl_(4).4H_(2)O`D. `SnCl_(4).5H_(2)O` |
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Answer» Correct Answer - D Stannic chloride `(SnCl_(4))` is hygroscopic and forms crystalline hydrates containing `3, 5, 6`, and `8` molecules of water of crystallization. The pentahydrate `SnCl_(4) . 5H_(2)O`, is known as "butter of tin" or "oxymuriate of tin." It is used as a mordant for dyes. |
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| 476. |
The most important ore of tin isA. pyrolusiteB. wolframiteC. stanniteD. cassiterite |
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Answer» Correct Answer - D Cassiterite, the natural tin `(IV)` oxide, `SnO_(2)`, is the principle ore of tin. `SnO_(2)` is reduced to the metal using `C` at `1200- 1300^(@)C` in an electric furnace. |
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| 477. |
Which of the following is incorrect regarding carbon monoxide?A. The carbon-oxygen bond in `CO` is very short `(113 p m)`, about the length that would be expected for a triple bond.B. The triple bond between `C` and `O` in `CO` is the strongest bond known with a bond enthalpy of `1070 kJ mol^(-1)`.C. The dipole moment of `CO` is very high.D. According to molecular orbital theory, the bond order of `CO` molecule is `3`. |
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Answer» Correct Answer - C The dipole moment of `CO` is very low due to the back donation of a pair of electrons from the more electronegative `O` to the less electronegative `C` atom. The molecular orbital configuration of `CO` is `sigma 1s^(2), sigma^**1s^(2),sigma2s^(2).sigma^**2s^(2)`, `{(pi2p_(x)^(2),,,,,),(,,sigma^**2p_(z)^(0),,,),(pi2p_(y)^(2),,,,,):}{(pi^**2p_(x)^(0),,,,),(,,sigma^**2p_(z)^(0),,),(pi^**2p_(y)^(0),,,,,):}` Bond order `= (N_(b)-N_(a))/(2) = (10-4)/(2)=3` |
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| 478. |
Which xenon compound has distorted octahedral shape ? |
| Answer» Correct Answer - `XeF_(6)` | |
| 479. |
The linear shape of `CO_(2)` is due to ……….A. `sp^(3)` hybridisation of carbonB. sp hybridisation of carbonC. `p pi - p pi` bonding between carbon and oxygenD. `sp^(2)` hybridisation of carbon |
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Answer» Correct Answer - B::C Sigma bond formed by s-s overlap, s-p overlap and p-p overlapping, pi `(pi)` bond formed by p-p overlapping. The structure of `CO_(2)` is `{:(p-p(pi),p-p(pi)),(O=C,=O),(sp-p(sigma),sp-p(sigma)):}` is 2 sigma bonds and 2 pi bonds Hybridisation of `CO_(2)` is sp and the shape is linear. Due to pi bond, it is `p pi - p pi` bonding between carbon and oxygen. |
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| 480. |
A compound of boron X reacts at `200^(@)C` temperature with `NH_(3)` to give another compound Y which is called as inorganic benzene. The compound Y is a colourless liquid and is highly light sensitive. Its melting point is `-57^(@)C`. The compound X with excess of `NH_(3)` and at a still higher temperature gives boron nitride `(BN)_(n)`. The compounds X and Y are respectively:A. `B_(2)H_(6),B_(3)N_(3)H_(6)`B. `B_(2)O_(3),B_(3)N_(3)H_(6)`C. `BF_(3),B_(3)N_(3)H_(6)`D. `B_(3)N_(3)H_(6),B_(2)H_(6)` |
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Answer» Correct Answer - A (i) Reaction of ammonia with diborane gives initially `B_(2)H_(6).2NH_(3)` which is fermulated as `[BH_(2)(NH_(3))_(2)]+[NH_(4)]` further heating gives borazine, `B_(3)N_(3)H_(6)` also called borazole. `underset(underset((X))("Diborane"))(3B_(2)H_(6))+6NH_(3)overset(473K)(rarr)underset(underset((Y))("Borazole"))(2B_(3)N_(3)H_(6))+12H_(2)` Borazole has cyclic structure and is isoelectronic and isosteric with benzene and thus called inorganic benzene to triborine or borazine. (ii) Diborane can be prepared by the reduction of `BF_(3)` with lithium aluminium hydride in diethyl ether `4BF_(3)+3LiAlH_(4)rarr underset((X))(2B_(2)H_(6))+2AlF_(3)+3LiF`. |
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| 481. |
Assertion : Atomic radius of Ga is larger than that of aluminium Reason : Atomic radius always increases down the groups. |
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Answer» Correct Answer - D There are deviations in properties of elements of a group in p-block Atomic radius of Ga is less than that al Al because of the presence of additional 10 d-electrons which offer poor screening effect for the outer electrons from the increased nuclear charge in gallium. |
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| 482. |
Group `13` elements form complexes much more readily than the `s`-block elements because ofA. smaller ionic sizeB. increased ionic chargeC. higher charge densityD. all of these |
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Answer» Correct Answer - C Both tetrahedral complexes such as `Li[AlH_(4)]` and `Na[BH_(4)]`, and octahedral complexes such as `[GaCl_(6)]^(3-)`, `[InCl_(6)]^(3-)`, and `[TlCl_(6)]^(3-)` are known. |
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| 483. |
The oxidation number of `Ga` in `GaCl_(2)` isA. `+2`B. `+3`C. `+1`D. both `(2)` and `(3)` |
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Answer» Correct Answer - D The compound `GaCl_(2)` actually exists as `Ga^(+)[GaCl_(4)]^(-)` which contains `Ga(+1)` as well as `Ga(+3)`. |
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| 484. |
Which of the following is water-soluble and strongly basic?A. `Al(OH)_(3)`B. `Ga(OH)_(3)`C. `In(OH)_(3)`D. `TIOH` |
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Answer» Correct Answer - D Thallous hydroxides `(TIOH)` like alkali metal hydroxides is water-soluble and strongly basic. Other hydroxides are water-insoluble. `Al(OH)_(3)` and `Ga(OH)_(3)` are amphoteric but `In(OH)_(3)` is basic. |
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| 485. |
Which of the following compounds are acidic?A. `B(OH)_(3)`B. `Al(OH)_(3)`C. `BF_(3)`D. `CO_(2)` |
| Answer» Correct Answer - A::C::D | |
| 486. |
Which of the following is most acidic?A. `N_(2)O_(5)`B. `P_(2)O_(5)`C. `As_(2)O_(5)`D. `Sb_(2)O_(5)` |
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Answer» Correct Answer - 1 `N_(2)O_(5)` is most acidic because acidic nature of oxides decreases on moving down a group due to increase of metallic character. |
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| 487. |
Which of the following phosphorus is the most reactive?A. Red `P`B. White `P`C. Scarlet `P`D. Violet `P` |
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Answer» Correct Answer - 2 White phosphours is the most reactive (due to the presence of discrete `P_(4)` molecules) while black phosphorus is the least reacrive. Thus, white phosphorus is stored under water to protect it from air while red and black phosphorus are stable in air. |
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| 488. |
Which of the following is used in the preparation of chlorine?A. only `MnO_(2)`B. only `KMnO_(4)`C. Both `MnO_(2)` and `KMnO_(4)`D. Either `MnO_(2)` and `KMnO_(4)` |
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Answer» Correct Answer - 3 Cholrine can be prepared by heating concentratied hydrocholric acid with an oxidising agent such manganese dioxide, potassium permanganate, etc. `{:(MnO_(2)+2HCl rarr MnCl_(2)+H_(2)O+O),(2HCl+O rarr Cl_(2)+H_(2)O),(bar(MnO_(2)+4HCl rarr MnCl_(2)+H_(2)O+Cl_(2))),(2KMnO_(4)+16HCl rarr 2KCl+2MnCl_(2)+8 H_(2)O+5 Cl_(2)):}` |
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| 489. |
which of the following nobel gases is used in shop signs and street lamps?A. `Xe`B. `Kr`C. `Ne`D. `Ar` |
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Answer» Correct Answer - 3 Because the characteristic red glow produced when an electrical discharge is passed through neon at low pressure is able to penetrate fog. It finds a use in devices for illuminating airfields. |
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| 490. |
Which has maximum boiling point ?A. KrB. XeC. HeD. Ne |
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Answer» Correct Answer - B Xe has the maximum boiling point because of its maximum size and also maximum van der Waals forces of attraction. |
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| 491. |
Give reason for the bleaching action of `Cl_(2)`. |
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Answer» Bleaching by chlorine occurs in the presence of moisture. In fact, it releases nascent oxygen on reacting with `H_(2)O` which carries bleaching. Since the reaction cannot be reversed, the bleaching by chlorine is permanent. `Cl_(2)+H_(2)O to 2HCl+underset(("Nascent"))(O)` |
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| 492. |
the bleaching action of chlorine is due toA. reductionB. oxidationC. hydorgenationD. chlorination |
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Answer» Correct Answer - 2 Dry `Cl_(2)(g)` does not act as a bleaching agent. But in the presence of moisture or in aqueous solution `Cl_(2)` act as a powerful bleaching agent and bleching vegetable or organic matter `Cl_(2)+H_(2)Orarr2HCl+[O]` Coloured substance `+[O] rarr` Colourless substance .Due to oxidation bleaching action of `Cl_(2)` (unlike that of `SO_(2))` is permanent. |
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| 493. |
Which has bleaching action due to reducing property and it is temporary?A. `H_(2)O_(2)`B. `O_(3)`C. `SO_(2)`D. `Cl_(2)` |
| Answer» Correct Answer - C | |
| 494. |
`FeS_(2)+O_(2) to `? The product formed in above reaction isA. `FeO+SO_(2)`B. `Fe_(2)O_(3)+SO_(2)`C. `Fe_(2)O_(3)+SO_(3)`D. `FeO+SO_(3)` |
| Answer» Correct Answer - B | |
| 495. |
Sulphur vapours exhibit some paramagnetic behaviour. Explain. |
| Answer» Sulphur is paramagnetic in the presence of two unpaired electrons in `pi^(**)` antibonding orbitals. | |
| 496. |
Form of sulphur which shows paramagnetic behaviourA. `S_(8)`-RhombicB. `S_(8)`-MonoclinicC. `S_(2)` is vapour stateD. Not possible |
| Answer» Correct Answer - C | |
| 497. |
Xenon has closed shell configuration but gives compounds with fluorine. Explain. |
| Answer» Fluorine can cause electron promotion to 5d orbitals in xenon atom. | |
| 498. |
The group of noble gas elements is called zero group. Why ? |
| Answer» With the exception of helium `(1s^(2))`, all other noble gas elements have `ns^(2)p^(6)` electronic configuration. Thus, they have highly symmetrical configuration and therefore, donot form compounds undr ordinary conditions. In other words they show zero valency and are included in the zero group of the periodic table. | |
| 499. |
Noble gas elements form compounds only with fluorine and oxygen. Explain. |
| Answer» Noble gas elements have highly symmetrical electronic configuration and therefore, high ionisation enthalpies. Since all their occupied orbitals are filled, they normally cannot form any compounds. However, the elements fluorine and d-orbitals. This, too, is possible mainly in case of xenon in which the ionisation enthalpy is the minimum and the promotion of electrons is rather easy. No other elements are in a position to form compounds with noble gas elements. For details, consult Section 33. | |
| 500. |
The oxidation states exhibites by hydrogen in its various compounds are `:` |
| Answer» Chlorine exhibits oxidation states `-1, +1,+3,+5,+7` in its compounds | |