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.
| 51. |
Which of the following has the stronger bond?A. F-BB. F-ClC. F-BrD. Cl-Br |
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Answer» Correct Answer - A `B(Z=5): 1s^2 2s^2 2p_x^1` `F(Z=7): 1s^2 2s^2 2p_x^1 2p_y^2 2p_z^1` F-B bond is the strongest. It is due to effective p-p overlap between half filled `2p_z` orbital of F atom and half filled `2p_x` orbital of B atom. p- Orbitals of almost equal size overlap more effectively. |
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| 52. |
Which of the following reaction involves oxidation and reduction ?A. `H_2 + Br_2 to 2 HBr`B. `HBr + AgNO_3 to AgBr + HNO_3`C. `NaBr + HCl to NaCl + HBr`D. `Na_2O + H_2SO_4 to Na_2SO_4 + H_2O` |
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Answer» Correct Answer - A Only the reaction `H_2^0 + Br_2^0 to overset(+1)(2H)overset(-1)(Br)` is a redox reaction in which oxidation numbers of elements change |
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| 53. |
The reaction `3ClO^(-)(aq)rarrClO_(3)^(-)(aq)+2Cl^(-)(aq)` an example of :A. Oxidation reactionB. Reduction reactionC. Disproportionation reactionD. Decomposition reaction |
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Answer» Correct Answer - C `3overset(+1)(Cl)O^(-)(aq) to overset(+5)(Cl)O_3^(-) (aq) +2overset(-1)(Cl^(-))(aq)` In this reaction oxidation state of Cl simultaneously increase (from +1 to 5) and decrease (first +1 to -1). Thus it is an example of disproportionation reaction. |
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| 54. |
Mark the element which shows only one oxidation state in its compoundsA. FB. ClC. BrD. I |
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Answer» Correct Answer - A Fluorine always shows only one oxidation state. Its oxidation state in all its compounds is -1. |
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| 55. |
The ionic character in H-X bond is highest inA. HBrB. HFC. HClD. HI |
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Answer» Correct Answer - B H-F due to highest electronegativity difference of F and H (4.0-2.1=1.9) |
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| 56. |
Which one of the following halogens has the highest bond energy ?A. `F_2`B. `Cl_2`C. `Br_2`D. `I_2` |
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Answer» Correct Answer - B Shorter the bond, stronger the bond, more its bond dissociation energy. However bond dissociation energy of `Cl_2` is more than `F_2`. This is despite the fact that F-F bond is shorter than Cl-Cl bond. Correct order of bond energies is `Cl_2 gt Br_2 gt F_ 2 gt I_2` |
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| 57. |
Which of the following has the highest bond energy?A. FluorineB. BromineC. IodineD. Chlorine. |
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Answer» Correct Answer - D Bond energy of Fluorine (although `F_2` has smallest bond length) is less than `Cl_2 and Br_2` due to greater interelectronic repulsions between the lone pair of electrons on F atom `{:("Halogen",F-F, Cl-Cl, Br-Br,I-I),("Bond dissociation energy (kcal/mol)",38,57,45.5,35.5):}` So chlorine has highest bond energy. |
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| 58. |
A halogen atom combines with another non-metal to form a compound with slight metallic lustre. The halogen atom isA. FB. BrC. CID. I |
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Answer» Correct Answer - D Down the group, non-metallic character decreases. Iodine shows slight metallic character in compounds like ICl and `I Cl_3`. |
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| 59. |
Which of the following elements exhibits the most basic properties?A. FB. ClC. BrD. I |
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Answer» Correct Answer - D A base is a substance which can easily give its lone pair of electrons. This tendency, in general, increases down the group due to increase in atomic radii. Thus out of F, CI, Br and I, I is most basic |
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| 60. |
Astatine is the element below iodine in the group 17 of the periodic table. Which of the following statement is not true for Astatine?A. It is less electronegative than iodineB. It will exhibit only - 1 oxidation stateC. It is composed of diatomic moleculesD. Intermolecular forces are stronger as compared to iodine. |
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Answer» Correct Answer - B Astatine shows negative, zero as well as positive oxidation state. |
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| 61. |
Which radical can bring about the highest oxidation state of a transition metal ?A. `Br^-`B. `Cl^-`C. `F^-`D. `I^-` |
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Answer» Correct Answer - C `F^-` since it possesses smallest size. |
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| 62. |
The compound which gives chlorine like smell is :A. `CHCl_3`B. ChloretoneC. `CaOCl_2`D. None |
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Answer» Correct Answer - C `CaOCl_2` has chlorine like smell. |
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| 63. |
Iodine stains on clothes can be removed byA. NaClB. NaBrC. KID. `Na_2S_2O_3` |
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Answer» Correct Answer - D `2Na_2S_2O_3 +I_2 to Na_2S_4O_6 + 2Nal` |
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| 64. |
Which of the following species has four lone..A. IB. `O^-`C. `Cl^-`D. He |
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Answer» Correct Answer - C `:underset(ddot)overset(ddot)I .,:underset(ddot)overset(ddot)(O^- .),:underset(ddot)overset(ddot)(Cl^(-) : ),He:` Only `Cl^-` has four lone pairs of electrons. |
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| 65. |
Ozonised oxygen can be obtained from `H_2O` the action ofA. Conc. `H_2SO_4`B. `KMnO_4`C. `MnO_4^(2-)`D. `F_2` |
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Answer» Correct Answer - D A mixture of `O_2 and O_3` is called ozonised oxygen |
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| 66. |
On boiling an aqueous solution of `KClO_(3)` with iodine, the following product is obtainedA. `KIO_3`B. `KClO_4`C. `KIO_4`D. KCl |
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Answer» Correct Answer - A `2KCIO_3 + I_2 to 2KIO_3 + Cl_2` |
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| 67. |
On heating `KClO_(3)` we get:A. `KClO_2 + O_2`B. `KCl + O_2`C. `KCl+ O_3`D. `KCl+O_2 + O_3` |
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Answer» Correct Answer - B `2KClO_3 overset(Delta) to 2KCl + 3O_2` |
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| 68. |
When `I_(2)` is dissolved in `C Cl_(4)`, the colour that results isA. BrownB. ColourlessC. VioletD. Bluish green. |
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Answer» Correct Answer - B `I_2` when dissolved in `C Cl_4` results in a violet coloured solution |
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| 69. |
Which of the following bonds will be most polar?A. N-ClB. O-FC. N-FD. N-N. |
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Answer» Correct Answer - C Greater the electronegativity difference more is the polarity of the covalent bond formed by the elements. Electronegativity of N is approximately equal to Cl. Thus N-Cl and N-N bonds are almost non-polar. Out of O-F and N-F, N-F bond is more polar as electronegativity of N is less than O and F is most electronegative. |
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| 70. |
Which of the following is used during the preparation of fluorine by Whytlaw-Gray metA. aqueous KFB. aqueous HFC. molten `KHF_2`D. `NH_4F` |
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Answer» Correct Answer - C In Whytlaw Gray method for the preparation of `F_2`, Molten `KHF_2` is used as an electrolyte. |
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| 71. |
The correct order of electronegativity among halogens is:A. F gt CI gt Br gt IB. Flt Cl lt Br lt IC. F gt Br gt Cl gtID. Flt Br lt Cllt I |
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Answer» Correct Answer - A `{:("Halogen",F,gtCl,gtBr,gtI),("Electronegativity",4.0,3.0,2.8,2.4):}` |
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| 72. |
Which of the following pairs represents 1st and 2nd most electronegative elements of the periodic table respectively ?A. Cl, FB. F, CIC. F,OD. I, C |
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Answer» Correct Answer - C Fluorine is the most electronegative and oxygen is the second most electronegative element of the periodic table. |
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| 73. |
Which of the following is called anhydrone ?A. `KHF_2`B. NaOClC. `(NaPO_3)_6`D. `KClO_3` |
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Answer» Correct Answer - D `KClO_3` (potassium chlorate) is called anhydrone |
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| 74. |
Fluorine reacts with cold dilute NaOH to giveA. NaF and `O_2`B. NaF and `OF_2`C. NaF and `H_2O_2`D. NaF, `H_2O_2 and F_2O`. |
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Answer» Correct Answer - B `2F_2+underset("Cold, dilute")(2NaOH)to OF_2 + 2NaF +H_2O` However with conc. NaOH, `O_2` is formed `2F_2 + underset("conc.")(4NaOH) to 4NaF + 2H_2O+O_2` |
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| 75. |
The solubility of iodine in water increases in the presence ofA. AlcoholB. ChloroformC. Sodium hydroxideD. Potassium iodide. |
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Answer» Correct Answer - D This is due to the formation of `I_3^-` ion. `KI + I_2 hArr KI_3 or I_2 + I^(-) to I_3` |
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| 76. |
The correct decreasing order of acidic character isA. HClO gt HBrO gt HIOB. HIO gt HBrO gt HClOC. HBrO gt HIO gt HClOD. HClO gt HIO gt HBrO |
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Answer» Correct Answer - A In oxy-acids, more the electronegativity, more is the acid strength. Electronegativity of Cl, Br and I is in the order Cl gt Br gt I. Therefore acid strength is also in the same order I.e.. HClO gt HBrO gt HIO. |
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| 77. |
When cold `NaOH` reacts with `Cl_(2)` which of the following is formedA. NaClOB. `NaClO_2`C. `NaClO_3`D. None |
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Answer» Correct Answer - A `({:(Cl_2+H_2Oto,HCl + HOCl),(NaOH+HCl to , NaCl+ H_2O),(NaOH+ HOCl to, NaOCl+H_2O):})/ul(2NaOH +Cl_2 to NaCl + NaOCl+H_2O)` |
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| 78. |
Which of the following describes the halogen element?A. They are monoatomic and form ion of the type `X^+`B. They are diatomic and form ion of type `X^+`C. They are diatomic and form ion of the type `X^(-)`D. They are polyatomic and form ion of the type `X^(-)` |
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Answer» Correct Answer - C Halogens are diatomic molecule `(X_2)` in the elemental state and form ion of the type `X^-` |
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| 79. |
Which of the following has least bond dissociation energy ?A. `F_2`B. `Cl_2`C. `Br_2`D. `I_2` |
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Answer» Correct Answer - D `I_2` has least bond dissociation energy (35.6 kcal/ mole) due to its largest size |
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| 80. |
In the reaction `HNO_3 + HF to H_2NO_3^(+) + F^(-)` base isA. HFB. `HNO_3`C. `HF and HNO_3`D. None |
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Answer» Correct Answer - B `HNO_3 +HF to H_2NO_3^(+) +F^(-)` In this reaction `HNO_3` accepts a `H^+` from HF. Thus in this reaction `HNO_3` acts as a base. |
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| 81. |
When chlorine is passed through KI and starch solutionA. A yellow colour is obtainedB. `l_2` is liberatedC. `Br_2` is liberatedD. `I_2` is liberated and solution becomes blue |
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Answer» Correct Answer - D `2KI + Cl_2 to 2KCl + I_2` |
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| 82. |
Which of the following reagent on treatment with KI gives iodine ?A. `ZnSO_4`B. `FeSO_4`C. `CuSO_4`D. `NiSO_4` |
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Answer» Correct Answer - C `CuSO_4 + 2KI to CuI_2 + K_2SO_4` `2CuI_2 to Cu_2I_2 +I_2` |
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| 83. |
Which one of the following statements about halogens is correct?A. `F_2` has lower bond dissociation energy thanB. The electron affinities are in order `F gt Cl gt Br gt I`C. HF is the strongest hydrohalic acidD. All halogens show variable oxidation states |
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Answer» Correct Answer - A Bond dissociation energy of `F_2` is less than `Cl_2`. |
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| 84. |
Which of the following elements is extracted commercially by the electrolysis of an aqueous solution of its compound ?A. ClB. BrC. AlD. Na |
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Answer» Correct Answer - A Chlorine `(Cl_2)` is obtained by electrolysis of aqueous solution of chlorides (e.g.. NaCl). Na cannot be obtained by this method |
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| 85. |
In which of the following pairs, the two species are isostructural :A. `BrO_3^(-) and XeO_3`B. `SF_4 and XeF_4`C. `SO_3^(2-) and NO_3^(2-)`D. `BF_3 and NF_3` |
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Answer» Correct Answer - A `BrO^-` and `XeO_3` are both pyramidal. All others have different geometries. For example, `SF_4` is trigonal bipyramidal and `XeF_4` is square planar, `SO_3^(2-)` is pyramidal while `NO_3^-` is trigonal planar: `BF_3` is trigonal planar and `NF_3` is pyramidal |
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| 86. |
Which of the following has the highest heat of hydration ?A. `F^-`B. `Cl^(-)`C. `Br^(-)`D. `I^(-)` |
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Answer» Correct Answer - A Smaller the size of ion, greater is the hydration energy |
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| 87. |
Which of the following do not form polyhalide ions ?A. FB. CIC. BrD. I. |
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Answer» Correct Answer - A F cannot form polyhalide ions. This is due to the absence of d-subshell in its valence shell. |
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| 88. |
In which of the following molecules /ions , are all the bonds not equal ?A. `SF_4`B. `SiF_4`C. `XeF_4`D. `BF_4^(-)` |
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Answer» Correct Answer - A `SF_4` has a trigonal bipyramidal geometry. Hence its axial bonds are longer (165 pm) than equatorial bonds (155 pm) |
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| 89. |
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 or KMnO_4` |
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Answer» Correct Answer - D `({:(MnO_2+2HCl to, MnCl_2+H_2O+O),(2HCl + O to ,H_2O +Cl_2):})/ul(MnO_2+4HCl to MnCl_2 +2H_2O + Cl_2)` `({:(2KMnO_4 + 6HCl to, 2KCl + 2MnCl_2 + 3H_2O +5O),(2HCl + O , to H_2O + Cl_2 "]"xx5):})/ul(2KMnO_4+16 HCl to 2KCl + 2MnCl_2 +8H_2O + 5Cl_2)` |
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| 90. |
In the preparation of chlorine from `HCl,MnO_(2)` acts asA. Oxidising agentB. Reducing agentC. Catalytic agentD. Dehydrating agent |
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Answer» Correct Answer - A `MnO_2 +4HCl to MnCl_2 + Cl_2 + 2H_2O` |
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| 91. |
Which of the following statement is true regarding electrolysis of molten IC l ?A. `I_2` is liberated at the cathodeB. `Cl_2` is liberated at the cathodeC. `I_2` is liberated at the anodeD. Both `I_2` and `Cl_2` are liberated at the anode. |
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Answer» Correct Answer - A `IC l to I^(+) + underset( "liberated at anode")(Cl^(-))` |
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| 92. |
Electrolysis of brine givesA. NaOHB. `H_2`C. `O_2`D. `Cl_2` |
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Answer» Correct Answer - A,B,D Electrolysis of brine (aqueous solution of NaCl) yields `Cl_2` (at anode), `H_2` (at cathode) and NaOH solution. |
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| 93. |
The solubility of iodine in water may be increased by addingA. ChloroformB. Potassium iodideC. Carbon disulphideD. Sodium thiosulphate. |
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Answer» Correct Answer - B The solubility of `I_2` in water increases by the addition of KI due to formation of polyhalide ion i.e., `I_3^-` `KI+I_2to KI_3` or `I^(-) +I_2 to I_3^(-)` |
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| 94. |
The solubility of iodine in water may be increased by addingA. Potassium iodideB. ChloroformC. Carbon disulphideD. Sodium thiosulphate |
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Answer» Correct Answer - B Adding KI to water increases the solubility of `I_2` in water. This is due to the formation of polyhalide `I_3^-` ion. `KI(aq) + I_2(s) to overset(+)(K)I_3^(-)(aq)` |
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| 95. |
Super halogen isA. `I_2`B. `Cl_2`C. `Br_2`D. `F_2` |
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Answer» Correct Answer - D Super halogen is `F_2` Due to its highest reactivity. |
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| 96. |
Oxidising action increases in halogen in the following orderA. CI lt Br lt I lt FB. Cl lt I lt Br lt FC. I lt F lt Cl lt BrD. I lt Br lt Cl lt F |
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Answer» Correct Answer - D Oxidising action of halogens decreases down the group. Therefore correct order is Ilt Brlt Cl lt lt F |
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| 97. |
When chlorine water is slowly cooled, we get greenish yellow crystals ofA. `Cl_2 .2H_2O`B. `Cl_2. 8H_2O`C. `Cl_2. 5H_2O`D. `Cl_2. 6H_2O` |
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Answer» Correct Answer - B `Cl_2 . 8H_2O` chlorine hydrate crystals are formed at `0^@C`. |
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| 98. |
Which of the following is not an oxyacid of chlorine ?A. HClB. `HClO_5`C. `HClO_2`D. `HClO_3` |
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Answer» Correct Answer - B Cl can exhibit maximum oxidation state of +7. |
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| 99. |
Chlorine is mixed with drinking water so thatA. Dirt is removedB. Water becomes colourlessC. Bacteria are killedD. Suspended impurities get removed. |
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Answer» Correct Answer - C Chlorine is used in the sterilisation of water (as a germicide and disinfectant). |
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| 100. |
Which of the following cannot decolourise the iodine solution ?A. `Na_2SO_3`B. `Na_2S_2O_3`C. NaClD. NaOH |
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Answer» Correct Answer - A NaCl has no reaction with iodine. |
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