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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.
| 151. |
`PCl_(3)` fumes in moist air on account ofA. disproportionationB. hydrolysisC. oxidationD. reduction |
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Answer» Correct Answer - 2 Phosphorus trichloride is readily hydroysed by water to phosphonic acid `H_(3)PO_(3)` (commenly called phosphorous acid), and hydrogen chloride gas which comes out in the forms of fumes: `PCl_(3)(l)+3H_(2)O(l)rarrH_(3)PO_(3)(aq)+3HCl(g)` |
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| 152. |
The number of `P-O-P` and `P-OH` bonds present respectively in pyrophosphoric acid molecule are |
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Answer» `HO-underset(OH)underset(|)overset(O)overset(||)P-O-underset(OH)underset(|)overset(O)overset(||)P-OH` `P-O-P` Bond =1 `P-OH` Bonds =4 Total no. of bonds =5 |
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| 153. |
Comment on the nature of two S-O bonds formed in `SO_(2)` molecule. Are the two bonds in the molecule equal ? |
| Answer» The two S-O bonds in the molecule are equal with bond length equal to 143 pm. For details, consult Section 16. | |
| 154. |
What happens when : (i) `PCl_(5)`, is heated (ii) `H_(3)PO_(3)` is heated |
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Answer» (i) `PCl_(5) overset("heat") to PCl_(3)+Cl_(2)` (ii) `4H_(3)PO_(3) overset("heat") to 3H_(3)PO_(4)+PH_(3)` |
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| 155. |
What happens when the following are heated ? `(i) PCl_(5) (ii) H_(3)PO_(3)`. |
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Answer» (i) `PCl_(5) overset("heat") to PCl_(3)+Cl_(2)` (ii) `4H_(3)PO_(3) overset("heat") to 3H_(3)PO_(4)+PH_(3)` |
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| 156. |
Arrange the following in order of decreasing N - O bond length `NO_(2)^(-),NO_(2)^(-),NO_(3)^(-)` |
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Answer» This is on account of the difference in the hybridistain states of the nitrogen atoms in the two ions. `NO_(2)^(-) , H=1//2[5+0-0+1]=3 (sp^(2)` hybridisation) `NO_(2)^(+) , H=1//2[5+0-1+0]=2` (sp hybridisation) |
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| 157. |
Which is a stronger reducing agent, `SbH_(3) " or " BiH_(3)` and why ? |
| Answer» `BiH_(3)` is a stronger reducing agent due to greater Bi-H bond length. | |
| 158. |
Which is a stronger reducing agent , `SbH_(3) " or " BiH_(3)` and why ? |
| Answer» `BiH_(3)` is a stronger reducing agent than `SbH_(3)` since Sb-H bond has smaller bond length as compared to bond length of Bi-H bond. | |
| 159. |
Maximum, ability of catenation is shown by ………………………. ,A. siliconB. leadC. germaniumD. carbon |
| Answer» Correct Answer - D | |
| 160. |
Assertion : Catenation tendency is weaker in nitrogen. Reason : Nitrogen exists as diatomic gas.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
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Answer» Correct Answer - B Single N-N bond is weaker because of high inter-electronic repulsions of the non-bonding electrons owing to the small bond length. |
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| 161. |
Silicon tetrafluoride reacts with `HF` to formA. `H_(2)[SiF_(4)]`B. `SiF_(6)^(2-)`C. `SiF_(6)^(4-)`D. `SiF_(2)` |
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Answer» Correct Answer - B Hydrogen fluoride converts silicon tetrafluoride into fluorosilicic acid: `SiF_(4) + 2HF rarr H_(2)SiF_(6)` |
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| 162. |
Which of the following is not hydrolyzed under normal conditions?A. `SiCl_(4)`B. `SnCl_(4)`C. `C Cl_(4)`D. `GeCl_(4)` |
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Answer» Correct Answer - C `C Cl_(4)` is not hydrolyzed by water under normal conditions because `C` does not have vacant `d`-orbitals to form a five-coordinate intermediate required for hydrolysis. |
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| 163. |
Diborane is instantly hydrolyzed by water to giveA. `H_(3)BO_(3) + H_(2)`B. `H_(3)BO_(3) + B_(2)O_(3)`C. `H_(3)BO_(3) + O_(2)`D. `H_(2)O_(3) + B_(2)O_(3)` |
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Answer» Correct Answer - A It is readily hydorlyzed by water or aqueous alkali `B_(2)H_(6) (g) + 6H_(2)O(l) rarr 2H_(3)BO_(3)(aq.) + 6H_(2)(g)` |
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| 164. |
Which of the trichlorides is hydrolyzed most easily?A. `SbCl_(3)`B. `NCl_(3)`C. `AsCl_(3)`D. `PCl_(3)` |
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Answer» Correct Answer - 2 The ease of hydrolysis depends upon the tendency of the control atom to attract the lone pair of electrons from water which decreases as the electronegativity of the central atom(`E`) in `ECl_(3)` decreases down the group . Thus, the ease of hydrolysis of trichlorids decreases in the order: `NCl_(3) gt PCl_(3) gt AsCl_(3) gt SbCl_(3) gt BiCl_(3)` |
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| 165. |
`SF_(6)` is a well known compound while `SH_(6)` does not exist. Explain. |
| Answer» Sulphur atom has a very small size. Therefore, six chlorine atoms cannot be linked with an atom of sulphur whereas six fluorine atoms can be linked because of smaller size. Moreover, chlorine being less electrongegative than fluorine cannot cause the promotion of electrons in the vacant d-orbitals as effectively as done by fluorine because of its higher electronegativity. | |
| 166. |
Which of the following hydridess is the strongest Lewis base?A. `PH_(3)`B. `NH_(3)`C. `SbH_(3)`D. `BiH_(3)` |
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Answer» Correct Answer - 2 All the hydries `(NH_(3)` to`BIH_(3)` behave as Lewis bases as they possess a lone pair of electrons on the central atom. As we move down the group, the size of the central atom increases and the line pair of electrons gets delocalized as it occupies a larger volume. Consequently, the elecrtron density on the central atom decreases causing a decrease in the tendecy to donate a pair of electrons. Hence , the basic strength (sometimes called basicity) decreases in the order: `NH_(3) gt PH_(3) gt AsH_(3) gt SbH_(3) gt BiH_(3)` |
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| 167. |
Predict hybridisation and shape of `SF_(4)` molecule. |
| Answer» `sp^(3)d`, trigonal bipyramidal geometry and see-saw structure. | |
| 168. |
Chlorine gas was first prepared byA. DavyB. BertholletC. ScheeleD. Mosely |
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Answer» Correct Answer - 3 Chlorine gas was discovered by Scheele in `1774` by the action of `HCI` on `MnO_(2)`. Bethelot named this gas oxymuriatic acid gas since he throught it to be an oxide of muriatic acid (old name of `HCI`) in `1810`, Davy established its elementary nature and named it chlorine on account of its greensih yellow colour (Greek chloros `rArr` greenish yellow). |
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| 169. |
Name three gases which can be prepared from chlorine gas. |
| Answer» Phosgene, Tear gas, Mustard gas. | |
| 170. |
A metal M reacts with sodium hydroxide to give a white precipitate X which is soluble in excess of NaOH to give Y. Compound X is soluble in HCI to form a compound Z. Identify M.X,Y and Z M , X , Y, ZA. `Si, SiO_(2), Na_(2)siO_(3), SiCI_(4)`B. `AI, AiI(OH)_(3), NaMgO_(3), AICI_(3)`C. `Mg, Mg(Oh)_(3), NaMgO_(3), MgCI_(2)`D. `Ca, Ca(OH)_(2) , Na_(2) CO_(3), NaHCO_(3)` |
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Answer» Correct Answer - B `underset((M))(2AI) + 2NaOH + 6H_(2)O to underset((X))(2AI(OH)_(3)) underset(NaOH)overset("Excess of")(to) underset((Y))(NaAIO_(2))` `underset((X))(2AI(OH)_(3)) 6HCI to underset((Z))(2AICI_(3)) + 6H_(2) O` |
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| 171. |
A balck powder when heated with Conc. HCI gives a greenish yellow. Gas. The gas as an oxidising and bleaching agent. When it is passed over slake lime, a white poweder is formed which is a ready source of gas. The back powder and white powder respectively areA. `KClO_(3) and NaClO_(3)`B. `MnO_(2) and Ca(OCl)_(2)`C. `MnO_(2) and KClO_(3)`D. `MnCl_(4) and COCl_(2)` |
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Answer» Correct Answer - B `underset("powder")underset("Black")(MnO_(2))+underset("(conc.)")(4HCl)rarrMnCl_(2)+2H_(2)O+underset("yellow gas")underset("Greenish")(Cl_(2))Cl_(2)+H_(2)Orarr2HCl+[O]" Coloured matter"+[O]rarr" Colourless matter "` `underset("lime")underset("Slaked")(2Ca(OH)_(2))+2Cl_(2)rarrunderset("(white)")underset("powder")underset("Bleaching")(Ca(OCl)_(2))+CaCl_(2)+2H_(2)O` |
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| 172. |
Assertion : Fluorine `(F_(2))` is a stronger oxidising agent than chlorine. Reason : Fluorine is more electrongegative than chlorine.A. If both assertion and reason are correct and reason is correct explanation for assertion.B. If both assertion and reason are correct but reason is not correct explanation for assertion.C. If assertion is correct but reason is incorrect.D. If both assertion and reason are incorrect. |
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Answer» Correct Answer - B Correct explanation : Fluorine has more negative electron gain enthalpy than chlorine. |
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| 173. |
Borazine is the product of reaction betweenA. `B_(2)H_(6)`B. `NH_(3)`C. `BF_(3)`D. `BCl_(3)` |
| Answer» Correct Answer - A::B | |
| 174. |
Which of the following reactions leads to the formation of borazine?A. `B_(2)H_(6) + NH_(3) underset("High temperature")overset("Excess" NH_(3))rarr`B. `B_(2)H_(6) + NH_(3) underset("Low temperature")overset("Excess" NH_(3))rarr`C. `B_(2)H_(6) + NH_(3) underset("High temperature")overset("Ratio" 2NH_(3) : iB_(2)H_(6))rarr`D. `B_(2)H_(6) + NH_(3) underset("Low temperature")overset("Ratio" 2NH_(3) : iB_(2)H_(6))rarr` |
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Answer» Correct Answer - C `B_(2)H_(6) + NH_(3) underset("High temperature")overset("Ratio" 2NH_(3) : lB_(2)H_(6))rarr B_(3)N_(3)H_(6)` |
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| 175. |
Which of the following is used in the manufacture of heat resistance borosilicate glass?A. Boron sesquioxideB. BoraxC. Boric acidD. All of these |
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Answer» Correct Answer - D About `35%` of `B` production is used to manufacture borosilicate glass. Conventional soda glass suffers from thermal shock, i.e., when a piece of glass is heated strongly, the outside becomes hot and tries to expands, while the inside is still cold because glass is such a poor conductor of heat. As a result of stress between the outside and the inside, the glass cracks. When `Na` ions in the glass structure are replaced by `B` atoms, the degree of glass expansion (more precisely called thermal expansivity) is less than half that of conventional glass. As a result, containers made of borosilicate glass, sold under trademarks such as pyrex `(R)`, are capable of being heated without great danger of cracking. |
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| 176. |
Upon heating`KClO_(3)` in presence of catalytic amount of `MnO_(2)`, a gas `W` is formed. Excess amount of `W` reacts with white phosphorus to given `X`. The reaction of `X` with pure `HNO_(3)` gives `Y` and `Z`. Y and Z are, respectivelyA. `N_(2)O_(4) " and " HPO_(3)`B. `N_(2)O_(4) " and " H_(3)PO_(3)`C. `N_(2)O_(3) " and " H_(3)PO_(4)`D. `N_(2)O_(5) " and " HPO_(3)` |
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Answer» Correct Answer - D It is the correct answer. `2KClO_(3) overset((MnO_(2))) underset("heat")to 2KCl+underset((W))(3O_(2))` `5O_(2)+P_(4) to underset((X))(P_(4)O_(10))` `P_(4)O_(10) + 4HNO_(3) to underset((Y))(2N_(2)O_(5))+underset((Z))(4HPO_(3))` |
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| 177. |
Which of the following oxidation states are the most characteristics for lead and tin, respectively?A. `+2, +2`B. `+4, +2`C. `+2, +4`D. `+4, +4` |
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Answer» Correct Answer - C Due to inert pair effect, `ns^(2)` electron pair of `Pb` does not participate in bonding. Thus, `+2` is the most characteristic oxidation state for `Pb`. However, for `Sn`, the inert pair effect is not so strong Thus, `+4` is the most characteristic oxidation state for `Sn`. |
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| 178. |
Dinitrogen pentoxide ,a colourless deliquescentsolid is ,prepared byA. reaction `NH_(4)NO_(3)` with an excess of oxygen `(NH_(4)NO_(3)+2O_(2)rarrN_(2)O_(5)+2H_(2)O)`B. dehydrating `HNO_(3)` with `P_(4)O_(10)` at a high temperature `(4HNO_(3)+P_(4)O_(10)rarr4HPO_(3)+2N_(2)O_(5))`C. dehydrating `HNO_(3)` with `CaO` at a high temperature `(2HNO_(3)+CaOrarrN_(2)O_(5)+Ca(OH)_(2))`D. reacting `NaNO_(3)` with `N_(2)O_(4) (NaNO_(3)+N_(2)O_(4)rarrN_(2)O_(5)+NaNO_(2))` |
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Answer» Correct Answer - 2 `N_(2)O_(5)`is prepared by distilling concentrated nitric with phosphorus pentoxide in a glass apparatus: `{:(2HNO_(3) rarr H_(2)O+N_(2)O_(5)),(P_(2)O_(5)+H_(2)O rarr 2HPO_(3)),(bar(P_(2)O_(5)+2HNO_(3) rarr 2HPO_(3)+N_(2)O_(5))):}` It is also prepared by the action of dry chlorine on solid silver nitrate at`95^(@)C` `4AgNO_(3)+2Cl_(2)rarr 4AgCl +2N_(2)O_(5) + O_(2)` |
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| 179. |
`AIF_(2)` is soluble in `HF` only in presence of `KF`. It is due to the formation ofA. `K_(3)[AlF_(3)H_(3)]`B. `K_(3)[AlF_(6)]`C. `AIH_(3)`D. `K[AlF_(3)H]` |
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Answer» Correct Answer - 2 Aluminium trifluorde is insoluble in anhydroous `HF` but dissoves on additon of `KF` beacause anhydrous `HF` is a covalent compound and is strongly `H-`bonded. Therefore, it does not yield `F^(-)` ion and hence `AlF_(3)` does not dissolve in `HF`. On the other hand, `KF` being an ionic compound contains `F^(-)` ions and hence combines with `AlF_(3)` to form the complex, thereby shifitng the equilibrium: `underset("Insoluble")(AlF_(3))(s) overset(HF)(hArr) AlF_(3)(HF) overset(KF)(rarr) underset(("soluble complex"))underset("Pot. hexafluridoalumunate (III)")` |
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| 180. |
What is the hybridisation of sulphur in `H_(2)SO_(4)` ? |
| Answer» Correct Answer - `sp^(3)` | |
| 181. |
What is oil of vitriol ? |
| Answer» Correct Answer - `H_(2)SO_(4)` | |
| 182. |
Boiling point of phosphine is less than that of ammonia though its molecule size is more. Assign reason. |
| Answer» In ammonia `(NH_(3))`, the molecules are involved in the intermolecular hydrogen bonding on account of the polarity of N-H bonds. But the same is not possible in molecules of phosphine `(PH_(3))` since the polarity of P-H bond is negligible as compared to N-H bond. This is due to lesser electronegativity of phosphorus (2.1) as compared to nitrogen (3.1). Therefore, boiling point of ammonia is more than that of phosphine. | |
| 183. |
Which oxide of nitrogen is paramagnetic and coloured ? |
| Answer» Correct Answer - `NO_(2)` | |
| 184. |
Ammonia reacts with red -hot cupric oxide to produceA. `Cu_(3)N_(2)`B. `NO`C. `N_(2)`D. `N_(2)O` |
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Answer» Correct Answer - 3 Ammonia is oxidized to dinitrogen when passed over heated copper `(II)` oxide: `3CuO+2NH_(3)rarr3Cu+3H_(2)O+N_(2)` |
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| 185. |
Liquid ammonia is used to refrigeration because of itsA. pyramidal shapeB. high dipole momentC. high heat of vaporizationD. stability |
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Answer» Correct Answer - 3 Ammonia condenses to aliquid at`-33.3^(@)C`.This boiling point is much higher than that of phosphine ,`PH_(3)(-134^(@)C)`, because ammonia molecules form strong hydrogen bonds with their neighbors. The ammonia molecules has a fairly large dipole moment which explains why liquid ammonia is such a good polar solvent. the molecules in liquid `NH_(3)` are associated by htdrogen bonding, as in water, and because considerable energy is needed to break these bonds and vaporize the substances as single molecules,the latent heat of vaporization is unusually very high`(327" calg"^(-1))`.Thus ,liquid `NH_(3)` is used as a refrigerant in ice plants. |
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| 186. |
`SiO_(2)` is solid while `CO_(2)` is gas. Why?A. A3-D broad network solidB. An insulatorC. SilicaD. An acidic oxide |
| Answer» Correct Answer - A::B::C::D | |
| 187. |
At room temperature, `CO_(2)` is a gas while `SiO_(2)` is a solid becauseA. `CO_(2)` is nonpolar but `SiO_(2)` is polarB. `SiO_(2)` has higher molecular mass than `CO_(2)`C. `CO_(2)` has covalent bonds but `SiO_(2)` has ionic bonds between the `Si` and `O` atomsD. None of these. |
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Answer» Correct Answer - D `CO_(2)` exists as a discrete molecule due to the formation of double bonds between the `C` and `O` atoms by `p_(pi) - p_(pi)` multiple bonding while silicon, unable to form such bonds with oxygen, has an infinite three - dimensional structure. |
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| 188. |
`H_(2)O` is liquid while `H_(2)S` is a gas at room temperature. Explain. |
| Answer» H-O bond is more polar than H-S bond because of greater electronegativity difference in the bonding atoms. As a result, `H_(2)O` molecules are involved in the intermolecular hydrogen bonding and get associated to be liquid at room temperature. Since intermolecular hydrogen bonding is negligible in the molecules of `H_(2)S`, they donot get associated and remain in the gaseous state at room temperature. For more details, consult text part (Section 16). | |
| 189. |
Which of the following statement is/are correct regarding halogens?A. All halogens form oxyacidsB. Oxidising power of halogen `F_(2) gt Cl_(2) gt Br_(2) gt l_(2)`C. Electron affinity of fluorine is highestD. All halogens show oxidation state from -1 to +7. |
| Answer» Correct Answer - A::B | |
| 190. |
The correct statements about the oxoacids `HClO_(4) " and " HClO_(3)` is (are) :A. The central in both the cases is `sp^(3)` hybridisedB. `HClO_(4)` is formed as a result of reaction between `Cl_(2) " and " H_(2)O`.C. The conjugate base of `HClO_(4)` is weaker base more than `H_(2)O`D. `HClO_(4)` is more acidic than HClO because of resonance stabilisition of anion. |
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Answer» Correct Answer - A::C::D All these options are correct. |
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| 191. |
What is the state of hybridisation of halogen atom in the Oxoacids of halogens ? |
| Answer» Correct Answer - `sp^(3)` hybridised | |
| 192. |
Give one example each in which halogens display positive oxidation states from `+1 " to " +7`. |
| Answer» `Icl(+1) , CiF_(3) (+3), ClO_(2)(+4), I_(2)O_(5)(+5), Cl_(2)O_(6)(+6), IF_(7)(+7)` | |
| 193. |
Which of the following correct about `[Icl_(4)]^(-)` and `iCl_(4)` compound |
| Answer» `Icl_(4)^(-)` and `XeF_(4)` are iso-structural and both have distorted square planar geometries. | |
| 194. |
The xenon compounds that are isostructural with `IBr_(2)^(-)` and `BrO_(3)^(-)` respectively are:A. linear `XeF_(2)` and pyramidal `XeO_(3)`B. bent `XeF_(2)` and pyramidal `XeO_(3)`C. bent `XeF_(2)` and planar `XeO_(3)`D. linear `XeF_(2)` and tetrahedral `XeO_(3)`. |
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Answer» Correct Answer - A `lBr_(2)^(-) " and " XeF_(2)` are both linear. `BrO_(3)^(-) " and " XeO_(3)` are both pyramidal. The pairs listed above are also iso-electronic in nature. It is the correct answer. |
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| 195. |
Halogens exist in `-1, +1, +3, +5 " and " +7` oxidation states. The only halogen which exists in `-1` oxidation state is :A. FB. ClC. BrD. I |
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Answer» Correct Answer - A F exists in only `-1` oxidatin state. |
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| 196. |
Why does phosphorus exist as `PCl_(5)` but nitrogen cannot exist as `NCl_(5)` ? |
| Answer» P can exhibit `+5` oxidation state in its compounds while N can not. | |
| 197. |
Give the formula and describe the structure of a noble gas species which is isostructural with : `(i) ICI_(4)^(-) (ii) Ibr_(2)^(-) (iii) BrO_(3)^(-)` |
| Answer» Icl is iso-structural with `XeF_(2)`. Both are linear in nature. | |
| 198. |
Give the structure of noble gas species isostructural with `Icl_(4)^(-)` |
| Answer» Correct Answer - `XeF_(4)` | |
| 199. |
Which one of the following does not exist? |
| Answer» `NeF_(2)` does not exist. | |
| 200. |
Assertion :Solubility of noble gases in water decreases with increases in atomic size Reason :Solubility of noble gases in water is due to instantaneous dipole induced dipole interactionA. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
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Answer» Correct Answer - D Solubility of noble gases in water increases with increasing size of the gas. Solubility of noble gases in water is due to dipole-induced dipole interaction. |
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