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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. |
Which of the following statements are not for phosphorus?A. Phosphorus is a non - metalB. It exists as a tetrahedral moecular solidC. Phosphorus is less reactive than nitrogenD. P - P bond is much weaker than N=N bond |
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Answer» Correct Answer - C Actually nitrogen is inert (due to greater bond order and bond dissociation energy) and is less reactive than |
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| 152. |
Yellow phosphorus reacts with `CuSO_4` solution to giveA. `Cu_(3)P`B. CuC. `H_(3)PO_(3)`D. `H_(3)PO_(4)` |
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Answer» Correct Answer - A::B::C::D Yellow phosphorus reacts with `CuSO_(4)` (aq) `3P_(4)+12CuSO_(4) +24H_(2)O to 4Cu_(3)P +8H_(3)PO_(3)+12H_(2)SO_(4)` `P_(4)+10CuSO_(4)+16H_(2)O to 10 Cu +4H_(3)PO_(4) +10H_(2)SO_(4)` Hence `CuSO_(4)` (aq) is used to renger harmless any phosphorus (yellow) which has been allowed to come into contact with the skin. |
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| 153. |
White Phosphorus may be removed from red Phosphorus byA. SublimationB. DistillationC. Dissolving in `CS_(2)`D. Heating with an alkali |
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Answer» Correct Answer - D White phosphorus is dissolved while Red phosphorus does not react. |
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| 154. |
Yellow phosphorus does not glow in (all gases at one atmospheric pressure)A. airB. air +`SO_(2)`C. pure `O_(2)`D. air+terpentine vapour |
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Answer» Correct Answer - B::C::D Yellow phosphorus glows only at certain partial pressure of `O_(2)`. It does not glow in pure `O_(2)` at one atmospheric pressure. This glow is quenched by certain substances like `SO_(2)` and turpentine. |
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| 155. |
Which of the following is not soluble in excess of water ?A. `AsCl_(3)`B. `SbCl_(3)`C. `BiCl_(3)`D. both (B) and (C) |
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Answer» Correct Answer - D Both `SbCl_(3)` and `BiCl_(3)` are not soluble in excess of water. It is due to the formation of insoluble SbOCl and BiOCl on partial hydrolysis. `SbCl_(3)+H_(2)O to SbOCl darr+2HCl` `BiCl_(3)+H_(2)O to BiOCl darr +2HCl` |
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| 156. |
From a mixture of yellow P and red P, yellow P can be removed byA. heating with conc. `H_(2)SO_(4)`B. heating with conc. `HNO_(3)`C. heating with NaOH (aq)D. none of these |
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Answer» Correct Answer - C Only yellow P reacts with NaOH(aq) `P_(4)+3NaOH+3H_(2)O to 3NaH_(2)PO_(2)+PH_(3)` |
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| 157. |
Correct formula of the complex formed in the brown ring test for nitrates isA. The reduciton of nitrate to nitric oxideB. OxidationC. of nitric oxide to nitrogen dioxideD. reduction of ferrous sulphide to iron |
| Answer» Correct Answer - A | |
| 158. |
Which of the following molecules in linear?A. `SO_(2)`B. `NO_(2)^(+)`C. `NO_(2)^(-)`D. `SCl_(2)` |
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Answer» Correct Answer - B `NO_(2)^(+) (":"ddot(O)=overset(+)(N)to underset(..)(ddot("O:")))` has a linear structure. |
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| 159. |
In obtaining soft water, the salt of oxy acids of phosphorus used isA. ChlorapatiteB. Microcosmic saltC. CalgonD. Rock phosphate. |
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Answer» Correct Answer - C Calgon is sodium hexametaphosphate. `(NaPO_(3))_(6)` or `Na_(2)[PO_(3))_(6)]` |
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| 160. |
What is not true about `POCl_3`?A. The molecule does not contain `p pi -p pi `bondB. The molecule contain three sigma bondC. The molecules contain `p pi - p pi ` bondD. The molecule contain `p pi -d pi ` bond |
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Answer» Correct Answer - D In `POCl_(3) ` ` p pi -dpi ` bond is formed between O and P |
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| 161. |
Which one of the following molecules will have unequal bond lengths ?A. `NF_(3)`B. `BF_(3)`C. `PF_(5)`D. `SF_(6)` |
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Answer» Correct Answer - C In `PF_(5)`, two axial bond are longer than three equitorial bonds. |
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| 162. |
Which of the following reacts most rapidly with oxygen of air at ordinary temperature?A. `CO_(2)`B. red PC. White PD. `N_(2)` |
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Answer» Correct Answer - C Because of its low ignition temperature |
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| 163. |
Solid `PCl_5` exists asA. Dimer `P_(2)Cl_(10)`B. `[PCl_(4)]^(+)[PCl_(6)]^(2-)`C. `[PCl_(3)][Cl_(2)]`D. `PCl_(5)` as mole |
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Answer» Correct Answer - B `PCl_(5)` (solid ) exists as `[PCl_(4)]^(+) [PCl_(6)]^(-)`. |
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| 164. |
With excess of water, `PCl_5` givesA. `H_(3)PO_(3)+HCl`B. `H_(3)PO_(2)+HCl`C. `H_(3)PO_(4)+HCl`D. `H_(4)P_(2)O_(7)+HCl` |
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Answer» Correct Answer - C Both pentachlorides and pentaqoxides give oxy (ic) acid . `PCl_(5)+4H_(2)O to H_(3)PO_(4)+5HCl` |
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| 165. |
What is hybridization of P in `PCl_5`?A. `sp^(3)`B. `sp^(3)d^(5)`C. `sp^(3)d`D. `sp^(2)` |
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Answer» Correct Answer - C P is `sp^(3)-d` hybridised in `PCl_(5)`. |
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| 166. |
`PCl_(3)` reacts with water to form :A. `PH_(3)`B. `H_(3)PO_(3),HCl`C. `POCl_(3)`D. `H_(3)PO_(4)` |
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Answer» Correct Answer - B `PCl_(3)+3H_(2)O to H_(3)PO_(3)+3HCl` |
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| 167. |
For `H_3 PO_3` and `H_3 PO_4`, the correct choice isA. `H_(3)PO_(3)` is dibasic and reducingB. `H_(3)PO_(3)` is dibasic and non-reducingC. `H_(3)PO_(4)` is tribasic and reducingD. `H_(3)PO_(3)` is tribasic and non-reducing. |
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Answer» Correct Answer - A `H_(3)P_(3)` is dibasic and reducing. |
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| 168. |
Which of the following contains a coordinate covalent bond?A. `N_(2)H_(5)^(+)`B. `BaCl_(2)`C. `HCl`D. `H_(2)O` |
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Answer» Correct Answer - A `H-underset(H)underset(|)ddot(N)-overset(H)overset(uarr)underset(H)underset(|)(N^(+))-H` `N_(2)H_(5)^(+)` has a co-ordinate covalent bond. |
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| 169. |
The number of P-O-P and P-O-H bonds present respectively, in pyrophosphoric acid molecule isA. 1 ,2B. 2 , 2C. 1 , 4D. 1 , 8 |
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Answer» Correct Answer - C Pyrophosphoric acid is `HO-overset(O)overset(||)underset(OH)underset(|)(P)-Ooverset(O)overset(||)underset(OH)underset(|)(P)-OH` There is one P-O-P and four P-O-H bonds. |
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| 170. |
`Cl-P-Cl` bond angles in `PCl_5` molecule areA. `120^(@)` and `190^(@)`B. `60^(@)` and `90^(@)`C. `60^(@)` and `120^(@)`D. `120^(@) ` and `30^(@)` |
| Answer» Correct Answer - A | |
| 171. |
The true statement of the acids of phosphorus `H_3 PO_2, H_3 PO_2` and `H_3 PO_4` isA. The order of their acidity is `H_(3)PO_(4) gt H_(3)PO_(3) gt H_(3)PO_(2)`B. All of them are reducing in natureC. All of them are tribasic acidsD. The geometry of phosphorus is tetrahedral in all the three. |
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Answer» Correct Answer - D `H_(3)PO_(2),H_(3)PO_(3)` and `H_(3)PO_(4)`, all have tetrahdedral geometry around phosphorus. |
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| 172. |
Among the oxoacids given below the correct decreasing order of acid strength is (I) `H_3 AsO_4` (II) `H_3 SbO_4` (III) `HNO_3` (IV) `H_3 PO_4`A. IVgtIIIgtIIgtIB. IIIgtIVgtIgtIVC. IIIgtIIgtIVgtID. IIIgtIgtIIgtIV |
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Answer» Correct Answer - B The decreasing order of acid strength is `HNO_(3) gt H_(3)PO_(4) gt H_(3)AsO_(4) gt H_(3)SbO_(4)` |
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| 173. |
P-O-P bond is present inA. `H_(4)P_(2)O_(6)`B. `H_(4)P_(2)O_(5)`C. both (A) and BD. None of these |
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Answer» Correct Answer - B `underset("Structure of " H_(4)P_(2)O_(5))(HO-overset(O)overset(||)underset(H)underset(|)(P)-O-overset(O)overset(||)underset(H)underset(|)(P)-OH ) " " underset("Structure of " H_(4)P_(2)O_(6))(HO-overset(HO)overset(|)underset(HO)underset(|)(P)-overset(OH)overset(|)underset(OH)underset(|)(P)-OH)` |
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| 174. |
The equivalent weight of phosphoric acid `(H_3 PO_4`) in the reactionA. 25B. 49C. 49D. 98 |
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Answer» Correct Answer - D `NaOH+H_(3)PO_(4) to NaH_(2)PO_(4) +H_(2)O` In this reaction , Eq. mass of `H_(3)PO_(4) `=mol. Mass `=3xx1+31+16xx4` `=3+31+64=98` |
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| 175. |
The element of group having lowest ionisation energy isA. AntmonyB. BismuthC. NitrogenD. Antimony |
| Answer» Correct Answer - B | |
| 176. |
`PH_3`, the hydride of phosphorus isA. MetallicB. IonicC. Non - MetallicD. Covalent |
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Answer» Correct Answer - D `PH_(3)` in gas or liquid phase is a covalent compound. |
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| 177. |
Which of the following is the correct statement for `PH_3`?A. It is less basic than `NH_(3)`B. It is less poisonous than `NH_(3)`C. Electronegativity of `PH_(3) gt NH_(3)`D. It does not show reducing properties. |
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Answer» Correct Answer - A `PH_(3)` is less basic than `NH_(3)` |
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| 178. |
Which of the following has lowest boiling point?A. NitrogenB. ArsenicC. PhosphorusD. Antimony |
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Answer» Correct Answer - C Because of the smallest size. |
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| 179. |
`NH_3` has a much higher b.p. than `PH_3` becauseA. `NH_(3)` has a larger molecular weightB. `NH_(3)` undergoes umbrella inversionC. `NH_(3)` forms hydrogen bondD. `NH_(3)` contains ionic bonds whereas `PH_(3)` contains covalent bonds. |
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Answer» Correct Answer - C Boiling point of `NH_(3)` is much more than `PH_(3)` . It is due to extensive H-bonding in `NH_(3)`. |
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| 180. |
Which of the following is not the property of nitrogen?A. CatenationB. Nitrogen bondingC. Low boiling pointD. Allotropy |
| Answer» Correct Answer - D | |
| 181. |
Amongst elements of Group 15 the property which increases down the group isA. Stability of - 3 oxideation stateB. Reducing charactaer of hydridesC. ElectronegativityD. Acidic nature of oxides |
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Answer» Correct Answer - C Because due to ncrease in size, M-H bond strength decreases down the group. |
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| 182. |
Which one of the following elements is most metallic?A. PB. AsC. SbD. Bi |
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Answer» Correct Answer - D Metallic character increases down the group as such Bi is most metallic. |
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| 183. |
The electronegativity of the following elements increases in the orderA. C , N , Si , PB. N , Si , C , PC. Si , P , C , ND. P , Si , N , C |
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Answer» Correct Answer - C Electronegativity increases in the order SiltP ltCltN (Here N is most electronegative). |
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| 184. |
Among the following species, identify the isostuctural pairs `NF_(3). NO_(3)^(-), BF_(3), H_(3)O, HN_(3)`A. `[NF_(3),NO_(3)^(-)]` and `[BF_(3),H_(3)O^(+)]`B. `[NF_(3),H_(3)O^(+)]` and `[NO_(3)^(-),BF_(3)]`C. `[NF_(3),H_(3)O^(+)]` and `[NO_(3)^(-),BF_(3)]`D. `[NF_(3),H_(3)O^(+)]` and `[HN_(3),BF_(3)]` |
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Answer» Correct Answer - C `NF_(3)` and `H_(2)O^(+)` are pyramidal, `NO_(3)^(-)` and `BF_(3)` are triangular planar. `{:(" "ddot(N) " " ddot(O^(+))),(" / | / | "),(" F F F H H H"),(),(" O F"),(" "uarr" "|),(" N B"),(" / \ / "),(" "O^(-)" O F F"):}` |
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| 185. |
Assertion : Nitrogen is less reactive than molecular oxygen. Reason: Bond length of `N_(2)` is shorter than that of oxygen.A. Both A and R are true and R is the correct explanation of AB. Both A and R are true but R is falseC. A is true but R is falseD. A is false but R is true |
| Answer» Correct Answer - A | |
| 186. |
There are several forms of solid phosphorus but only red and white forms are important. The white phosphorus consists of discrete tetrahedral `P_(4)` molecules. The structure of red phosphorus has not yet been completely determinated but there are evidences that it is polymeric and consists of chains of `P_(4)` tetrahdedral linked together. at room temperature , stable modification of elements phosphorus is red form. because of its highly polymerised structure, it is less volatile and less reactive than white phosphorus. in most of its compounds, phosphorus can have a valency of 3 or 5. phosphorus acid is peculiar because although it contains three hydrogen atoms per molecule, only two dissociation. When P is burnt in excess of `O_(2)`, a compound is obtained in which each molecules containsA. four atoms of P and six atoms of OB. four atoms of P and tenC. atoms of OD. two atoms of P and three atoms of O |
| Answer» Correct Answer - B | |
| 187. |
There are several forms of solid phosphorus but only red and white forms are important. The white phosphorus consists of discrete tetrahedral `P_(4)` molecules. The structure of red phosphorus has not yet been completely determinated but there are evidences that it is polymeric and consists of chains of `P_(4)` tetrahdedral linked together. at room temperature , stable modification of elements phosphorus is red form. because of its highly polymerised structure, it is less volatile and less reactive than white phosphorus. in most of its compounds, phosphorus can have a valency of 3 or 5. phosphorus acid is peculiar because although it contains three hydrogen atoms per molecule, only two dissociation. The two hydrogen atoms of phosphorus acid are acidic because.A. All the hydrogen atoms are attached to phosphorusB. All the hydrohen atoms are attached to oxygenC. two hydrogen atoms are attached to oxygenD. two hydrohen atoms are attached to posphorus |
| Answer» Correct Answer - C | |
| 188. |
Which of the following can act as a Lewis base?A. `NCl_(3)`B. `PCl_(3)`C. `SbCl_(3)`D. `NBr_(3)` |
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Answer» Correct Answer - A::D Trifluorides and trichlorides of P and Sb such as `PCl_(3)` and `SbCl_(3` act as Lewis acid. `NCl_(3)` and `NBr_(3)` act as Lewis base (All trihalides of N axcept `NF_(3)` act as Lewis base). |
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| 189. |
The cyanide ion `CN and N_(2)` are isoelectronic, but in contrast to `CN^(-), N_(2)` is chemically inert, because ofA. low bond energyB. Abesnce of bond polarityC. unsmmetrical electron distributionD. Presence of more number of electrons in bonding orditals |
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Answer» Correct Answer - B The bond in N=N is non-polar while it is polar in `":"bar(C)-=ddot(N)` |
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| 190. |
The oxide of nitrogen that is neutral in character isA. NOB. `NO_(2)`C. `N_(2)O`D. `N_(2)O_(3)` |
| Answer» Correct Answer - C | |
| 191. |
The basic character of hydrides of the `V`-group elements decreases in the orderA. `SbH_(3) gt PH_(3)gt AsH_(3) gt NH_(3)`B. `NH_(3) gt SbH_(3) gt PH_(3) gt AsH_(3)`C. `NH_(3) gt PH_(3) gt AsH_(3) gt SbH_(3)`D. `SbH_(3) gt AsH_(3) gt PH_(3) gt NH_(3)` |
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Answer» Correct Answer - C Basic character of hydrides of group 15 elements decreases down the group. This, basic character is in the order `NH_(3) gt PH_(3) gt AsH_(3) gt SbH_(3)` |
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| 192. |
The acidic character of oxides of group 15, `N_2 O_3, P_2 O_3, As_2 O_3, Sb_2 O_3` (in this order)A. weakens in above orderB. increasesC. first increases then weakns in the above orderD. remains unchanged |
| Answer» Correct Answer - A | |
| 193. |
Pernitric acid is chemicallyA. `HNO_(2)`B. `HNO_(3)`C. `H_(3)PO_(4)`D. `H_(3)PO_(2)` |
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Answer» Correct Answer - C The word per is used when one more oxygen atoms adds to `HNO_(3)`. |
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| 194. |
Which of the following is most acidic in character?A. `HNO_(2)`B. `HNO_(3)`C. `H_(3)PO_(4)`D. `H_(3)PO_(2)` |
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Answer» Correct Answer - B The -ic acids are more stronger than -ous acids. |
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