InterviewSolution
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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.
| 1. |
Concentrated `H_(2)SO_(4)` cannot be used to prepare HBr from NaBr , because it ,A. HBr oxidises `H_2SO_4`B. HBr reduces `H_2SO_4`C. HBr undergoes disproportionationD. KBr reacts very slowly |
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Answer» Correct Answer - B The HBr so formed reduces `H_2SO_4` and itself gets oxidised to evaluate `Br_2` `2HBr + H_2SO_4 to 2H_2O +SO_2 + Br_2` |
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| 2. |
In the reaction `3Br_(2) + 6CO_(3)^(2-) + 3H_(2)O to 5Br^(-) + 2BrO_(3)^(-)+6HCO_(3)^(-)`A. Bromine is oxidised and carbonate is reducedB. Bromine is both oxidised and reducedC. Bromine is reduced and water is oxidisedD. Bromine is neither oxidised nor reduced |
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Answer» Correct Answer - B `3Br_2 + 6CO_3^(2-) +3H_2O to 5Br^(-) + BrO_3^(-)+6HCO_3^(-)` In this reaction O.S. of Br changes from 0 (in `Br_2`) to -1 (in `Br^(-)` and +5 in `BrO_3^(-)`). Thus, in this reaction bromine is both oxidised (increase in O.S.) and reduced (decrease in O.S.). |
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| 3. |
Assertion :`I_2` is less soluble in Kl(aq) than in pure water Reason : Common ion effect reduces the solubility.A. Both A and R true and R is the correct explanation of AB. Both A and R true and R is not a correct explanation of AC. A is true but R is falseD. Both A and R is false |
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Answer» Correct Answer - D Oz is more soluble in Kl(aq). It is due to the formation of polyhalide, `I_3^-` ion. |
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| 4. |
If `I_2` is dissolved in aqueous KI, the intense yellow species `I_3^-` is formed. The structure of `I_3^-` ion isA. square pyramidalB. trigonal bipyramidalC. octahedralD. pentagonal bipyramidal. |
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Answer» Correct Answer - B Trigonal bipyramidal `(sp^3 d)` |
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| 5. |
Which of the following cannot work as oxidizing agent ?A. `O_2`B. `KMnO_4`C. `H_2O_2`D. `I^-` |
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Answer» Correct Answer - D `I^-` cannot act as an oxidising agent Le.. accept electron. All other `(O_2, H_2O_2 and KMnO_4)` are strong oxidising agents |
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| 6. |
Chlorine cannot displaceA. Fluorine from NaFB. Iodine from NalC. Bromine from NaBrD. None of the above. |
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Answer» Correct Answer - A `Cl_2` cannot displace fluorine from NaF as chlorine is less reactive than fluorine |
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| 7. |
Assertion (A): `I_(2)` can displace `CI_(2)` from `NaCIO_(3)`. Reason (R ): I is more electronetgative than CI.A. Both A and R true and R is the correct explanation of AB. Both A and R true and R is not a correct explanation of AC. A is true but R is falseD. A is false but R is true |
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Answer» Correct Answer - C Reason. In this reaction chlorine show +5 oxidation state and I is more electropositive than Cl |
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| 8. |
Covalent bonding of halogen is alwaysA. `pi` bondingB. `delta` bondingC. `sigma` bondingD. None of these |
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Answer» Correct Answer - C `sigma` bond formed by head on overlap of orbitals. |
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| 9. |
Which halogen does not show +7 oxidation state?A. ChlorineB. BromineC. IodineD. Fluorine |
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Answer» Correct Answer - D Fluorine shows only - 1 and zero oxidation state. |
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| 10. |
The general electronic configuration of the outermost orbit in halogen isA. `s^2p^6`B. `s^2p^5`C. `s^2p^4`D. `s^2p^3` |
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Answer» Correct Answer - B Halogens have seven electrons in their valence shell so these have valence shell electronic configuration of `ns^2 np^5` |
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| 11. |
The colour of the solid iodine isA. greenish yellowB. dark brownC. violetD. reddish brown. |
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Answer» Correct Answer - C Violet (purple black) |
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| 12. |
Desicchlora isA. anhydrous barium perchlorateB. anhydrous calcium chlorideC. anhydrous magnesium chlorideD. conc. `H_2SO_4` |
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Answer» Correct Answer - A Desicchlora is anhydrous barium perchlorate. |
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| 13. |
Which of the following can act as an acid in sulphuric acid ?A. `HNO_3`B. `H_3PO_4`C. `HClO_4`D. `H_2O` |
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Answer» Correct Answer - C `HClO_4` is a stronger acid than `H_2SO_4` `HClO_4 + H_2SO_4 to ClO_4^(-) + [H_3SO_4]^(+)` |
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| 14. |
In dilute aqueous solution HF is a weaker acid than HI, becauseA. H-F bond energy is greater than HI bond energyB. The hydration energy of `F^-` is higher than that of `I^-`C. Of the presence of hydrogen bonds in HFD. Fluorine is a stronger base as compared to iodine. |
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Answer» Correct Answer - A HI is strongest acid because due to largest size of 1, the H-I bond is weakest and its bond dissociation energy is least so it breaks most readily and hence HI is the strongest acid. The order of acidic strength is HI gt HBr gt HCl gt HF |
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| 15. |
Which one of the following is correct order of the size of iodine species ?A. `I gt I^(-) gt I^(+)`B. `I^(-) gt I gt I^(+)`C. `I^(+) gt I gt I^(-)`D. `I^(-) gt I^(+) gt I` |
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Answer» Correct Answer - B `I^(-) gt I gtI^(+)`. As the number of electron decreases (but proton number remains same) so effective nuclear charge increases and so size decreases. |
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| 16. |
Which one of the following is correct order of the size of iodine species ?A. `I gt I^(-) gt I^(+)`B. `I gt I^(+) gt I^(-)`C. `I^(+) gt I^(-) gt I`D. `I^(-) gt I gt I^(+)` |
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Answer» Correct Answer - D Size of anion is more than the neutral atom and size of cation is less than the neutral atom. As such correct order is: `I^(-) gt I gt I^(+)` |
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| 17. |
Which halogen can be purified by sublimation ?A. `F_2`B. `Cl_2`C. `Br_2`D. `I_2` |
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Answer» Correct Answer - D Out of different halogens, only iodine (s) on heating, directly converts into `I_2 (g)`. `I_2(s) overset(Delta) hArr I_2(g)` Thus, iodine can be purified by sublimation. |
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| 18. |
The acid used for etching the glass isA. HFB. `H_2SO_4`C. `HClO_4`D. Aqua regia. |
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Answer» Correct Answer - A HF since it dissolves `Na_2SiO_3`. |
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| 19. |
A greenish yellow gas reacts with an alkin metal hydroxide to form a halate which can be used in fireworks and saftey matches. The gas and the halate areA. `Br_2 , KBrO_3`B. `Cl_2 , KClO_3`C. `I_2 , NaIO_3`D. `Cl_2 , NaClO_3` |
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Answer» Correct Answer - B `3Cl_2(g) +6KOH(aq) overset(Delta)toKClO_3 + 5KCl + 3 H_2O` `Cl_2` is greenish yellow gas. `KClO_3` is used in, fire works and safety matches as an oxidising agent. |
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| 20. |
Chlorine reacts with sodium hydroxide under various conditions to giveA. Sodium hypochloriteB. Sodium chlorateC. Sodium chlorideD. None of the above. |
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Answer» Correct Answer - C `Cl_2 +underset("Cold,dilute")(2NaOH)to NaCl + underset("sod. hypochlorite")(NaClO)+H_2O` `3Cl_2 + 6NaOH to 5NaCl + underset("sod. chlorate")(NaClO_3)+3H_2OI` So sodium chloride is formed in both cases. |
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| 21. |
Which of the following reactions is possible ?A. `I_2+2NaBrtoBr_2+2Nal`B. `I_2+2NaCl to Cl_2 +2NaCl`C. `Br_2 + 2NaCl to Cl_2 + 2NaBr`D. `Cl_2 + 2NaBr to Br_2 + 2NaCl` |
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Answer» Correct Answer - D `Cl_2` being better oxidizing agent than `Br_2` will displace bromine from its salt. |
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| 22. |
Which of the following contains cationic iodine?A. `IF_7`B. IC lC. `I(CH_3COO)_3`D. None of these. |
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Answer» Correct Answer - B,C Iodine shows cationic oxidation states of only `I^+` and `I^(3+)`. Thus, `IF_7` does not contain cationic iodine. |
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| 23. |
Amongst the following acids which is the weakestA. HFB. HClC. HBOD. HI |
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Answer» Correct Answer - A HF (because of strongest bond). |
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| 24. |
Iodine deficiency in diet is known to causeA. Beri-BeriB. GoitreC. RicketsD. Night blindness |
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Answer» Correct Answer - B Goitre is caused by the deficiency of iodine. |
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| 25. |
Oxidation of thisulphate `(S_(2)O_(3)^(2-))` ion by iodine givesA. `S_4 O_6^(2-)`B. `S_2O_6^(2-)`C. `SO_4^(2-)`D. `SO_3^(2-)` |
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Answer» Correct Answer - C `underset("Sulphite ion")(SO_3^(2-)(aq))+H_2O (l) + I_2(s) to SO_4^(2-)(aq) + 2I^(-)(aq) +2H^(+)(aq)` |
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| 26. |
Which one is the anhydride of `HClO_4` ?A. `Cl_2O`B. `ClO_2`C. `Cl_2O_6`D. `Cl_2O_7` |
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Answer» Correct Answer - D `2 HClO_4 to H_2O + Cl_2O_7` Thus, `Cl_2O_7` is anhydride of `HClO_4` |
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| 27. |
Which of the following halogens does not form its oxyacids ?A. FluorineB. ChlorineC. BromineD. Iodine. |
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Answer» Correct Answer - A Fluorine does not form oxyacids. |
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| 28. |
Which of the following gives correct arrangement of compounds involved based on their bond strength?A. HF gt HCl gt HBr gt HIB. HI gt HBr gt HCl gt HFC. HF gt HBr gt HCl gt HID. HF gt HCl gt HBr gt HI |
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Answer» Correct Answer - A Shorter the bond, stronger the bond. Smaller the atomic (size of one of the atom, other being the same) shorter is the bond length. Atomic radii of halogens are in the order : F lt Cl lt Br lt I Therefore bond length of HX is in the order : HFlt HCl lt HBr lt HI Bond strength is in the order HF gt HCl gt HBr gt HI |
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| 29. |
The correct order of acidic strength isA. `Cl_2O_7 gt SO_2 gt P_4O_10`B. `CO_2 lt N_2O_5 gt SO_3`C. `Na_2O gt MgO gt Al_2O_3`D. `K_2O gt CaO gt MgO` |
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Answer» Correct Answer - A In a period, acidic strength of oxide increases along the period. Thus only correct order of acid strength is `Cl_2O_7 gt SO_2 gt P_4O_10` In a group, acid strength of oxide decreases down the group |
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| 30. |
Which one of the following are pseudohalide ions ?A. `CNO^-`B. `RCOO^-`C. `OCN^-`D. `N N N^-` |
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Answer» Correct Answer - B `HCOO^-` is not a pseudohalide. |
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| 31. |
When `I_2` is passed through KCI, KF and KBr solutionsA. `Cl_2 and Br_2` are evolvedB. `Cl_2` is evolvedC. `Cl_2, Br_2 and F_2` are evolvedD. None of these. |
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Answer» Correct Answer - D As I is less reactive than Cl, Br and, it cannot displace any halogen (Cl, Br or I) |
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| 32. |
` KF` combines with to form `KHF_2`. The compound contains the species :A. `K^(+), F^(-) and H^(+)`B. `K^(+), F^(-) and HF`C. `K^(+) and [HF_2]^-`D. `[KHF]^(+) and F^(-)` |
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Answer» Correct Answer - C `KF+HF to KHF_2` `KHF_2 hArr K^(+)+[HF_2]^(-)` |
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| 33. |
For the electron affinity of halogens (with `-ve` sign), which of the following is correct?A. Br gt FB. F gt ClC. Br gt ClD. F gt I |
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Answer» Correct Answer - D `{:("Halogen",F,Cl,Br,I),("Electron affinity (eV)",-3.6,-3.8,-3.5,-3.2):}` The low value of electron affinity of fluorine is probably due to small size of fluorine atom i.e., electron density is high which hinders the addition of an extra electron. |
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| 34. |
Sea weeds are important source ofA. IodineB. BromineC. SulphurD. Chlorine |
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Answer» Correct Answer - A Sea weeds are an important source of iodine. |
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| 35. |
Sea weeds are important source ofA. IronB. ChlorineC. IodineD. Bromine |
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Answer» Correct Answer - C Sea weeds are important source of iodine. |
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| 36. |
Which of the following represents the correct order of increasing `pK_a` values of the given acids?A. `HClO_4lt HNO_3 lt H_2CO_3 lt B(OH)_3`B. `HNO_3 lt HClO_4 lt B(OH)_3 lt H_2CO_3`C. `B(OH)_3 lt H_2CO_3 lt HClO_4 lt HNO_3`D. `HClO_4 lt HNO_3 lt B(OH)_3 lt H_2CO_3` |
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Answer» Correct Answer - A More the `pK_a` value, weaker is the acid. `HClO_4` is a stronger acid than `HNO_3` (almost same electronegativity of N and Cl, but higher oxidation state of Cl In `HClO_4` than N in `HNO_3`). Both `H_2 CO_3 and B(OH)_3` are very weak acids. `CO_3^(2-)` (from `H_2CO_3`) is resonance stabilized while no such resonance is possible in `[B(OH)_4]^(-)` (from `H_3BO_3`) `H_2CO_3 (aq) hArr 2H^(+) (aq) + CO_3^(2-)(aq)` `B(OH)_3(aq) +H_2O (l) hArr [B(OH)_4]^(-)(aq) + H^(+)(aq)` Thus, correct order of acid strength is `B(OH)_3 lt H_2CO_3 lt HNO_3 lt HClO_4` Order of increasing `pK_a` values `B(OH)_3 gt H_2CO_3 gt HNO_3 gt HClO_4` |
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| 37. |
Which of the following hydrohalic acids has the highest value of dipole moment?A. HFB. HClC. HBrD. HI |
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Answer» Correct Answer - A HF has highest value of dipole moment due to greater electronegativity difference |
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| 38. |
Chlorine reacts with sulphur to formA. `SCl_4`B. `SCl_2`C. `SCl_6`D. None of the above |
| Answer» Correct Answer - A | |
| 39. |
Fluorine does not show positive oxidation states due to the absence ofA. d-orbitalsB. s-orbitalsC. p-orbitalsD. None |
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Answer» Correct Answer - D Fluorine does not show +ve oxidation state as fluorine is the most electronegative element |
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| 40. |
Which one of the following is the true covalent oxide of iodine?A. `I_2O_4`B. `I_2O_5`C. `I_2O_7`D. `I_2O_9` |
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Answer» Correct Answer - B In general, higher the oxidation state, more is the covalent character of the oxide. `I_2 O_7 and I_2O_9` do not exist. `I_2O_4` is ionic in nature. It is infact iodyl iodate `[IO]^(+) [IO_3]^(-)`. The only covalent oxide of iodine is `I_2O_5` |
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| 41. |
The acid which cannot be kept in glass bottlesA. HFB. HClC. HBrD. HI |
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Answer» Correct Answer - A Because HF attacks glass bottles. |
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| 42. |
The product formed during reaction of `NH_3 and I_2` are:A. `NI_3 and HI`B. `NH_3,NI_3 and HI`C. `NH_4I`D. `NH_4I and HI` |
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Answer» Correct Answer - B `2NH_3 + 3I_2 to NH_3NI_3+ 3HI` |
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| 43. |
In which solution halogen molecules tend to disproportionate ?A. In `H_2SO_4`B. In cold `H_2O`C. In hot NaOHD. In hot water |
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Answer» Correct Answer - C In hot basic medium `OC l^(-)` disproportionates `3OCl^(-) to 2Cl^(-) + ClO_3^-` |
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| 44. |
Fluorine is more reactive than chlorine becauseA. fluorine has lower bond energyB. fluorine has a greater ionisation potentialC. the covalent bond in fluorine molecule is weakerD. fluorine has no available d-orbitals. |
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Answer» Correct Answer - A Smaller is the bond energy, more is the reactivity |
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| 45. |
Fluorine is obtained by the interaction of `K_2MnF_6` with Lewis acid `SbF_5` because of theA. Acidolysis of `MnF_4`B. Decomposition of `MnF_4`C. Ionisation of `MnF_4`D. Decomposition of `SbF_6` |
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Answer» Correct Answer - B `({:(2K_2MnF_6+4SbF_5 to, 4KSbF_6+ 2MnF_4),(2MnF_4 to, 2MnF_3 + F_2):})/ul(2K_2MnF_6 +4SbF_5 to 4KSbF_6+2MnF_3 +F_2)` Here stronger Lewis acid `SbF_5` displaces weaker acid `MnF_4` from `K_2MnF_6`. Initially formed `MnF_4` being unstable decomposes to `MnF_3` and `F_2`. |
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| 46. |
Which of the following is a false statement ?A. Hydrogens are strong oxidising agentsB. Halogens show only-1 oxidation stateC. HF molecules form intermolecular hydrogen bondingD. Fluorine is highly reactive. |
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Answer» Correct Answer - B Except for fluorine, other halogens show number of positive oxidation states along with common -1 oxidation state. All other statements are correct. |
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| 47. |
Which of the following is a false statement ?A. Halogens are strong oxidising agentsB. Halogens show only one oxidation state of -1C. HF molecules form intermolecular hydrogen bondingD. Fluorine is highly reactive. |
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Answer» Correct Answer - B Halogens can show negative, zero as well as positive oxidation states. |
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| 48. |
The compound used for the preparation of `UF_6` in the enrichment of `._92 U^(235)` isA. `AlF_3`B. `CaF_2`C. HFD. `CIF_2` |
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Answer» Correct Answer - D Interhalogen compound `ClF_3` is used to convert uranium into `UF_6` ` U(s) +3CIF_3 (l) to UF_6(g ) +3CIF(g)` `UF_6(g)` is used for enrichment of `U^(235)` |
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| 49. |
The compounds used as gaseous insulators in high voltage generators isA. `SeF_4`B. `SiF_4`C. `SF_4`D. `SF_6` |
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Answer» Correct Answer - D `SF_6` is used as a high voltage insulator |
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| 50. |
Assertion (A): Bond energy of CI-CI bond is more than F-F bond. Reason (R ): Shorter the bond length, stronger the bond, more is the bond energy.A. Both A and R true and R is the correct explanation of AB. Both A and R true and R is not a correct explanation of AC. A is true but R is falseD. A is false but R is true |
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Answer» Correct Answer - B Reason. Lower bond energy of `F_2`, despite shorter bond length is due to repulsion between lone pairs on two F atoms. |
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