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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.
| 801. |
Hydridisation of the central atom in `BrF_(5)` molecule is :A. `sp^(3)`B. `dsp^(2)`C. `sp^(3)d^(2)`D. `d^(3)sp^(3)` |
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Answer» Correct Answer - C `H=(1)/(2) (7+5-0+0)=sp^(3)d^(2)` |
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| 802. |
Boric acid `(H_(3)BO_(3))` prepared fromA. boraxB. boron trihalidesC. colemaniteD. all of these |
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Answer» Correct Answer - D By treating a hot concentrated solution of borax with hydrocloric or sulhuric acid: `Na_(2)B_(4)O_(7) + H_(2)SO_(4) + 5H_(2)O rarr 4H_(3)BO_(3) + Na_(2)SO_(4)` By the hydrolysis of boron trihalides : `BCl_(3) + 3H_(2)O rarr H_(3)BO_(3) + 3HCl` By passing sulphurr dioxide through the solution of colemanite in boiling water. `Ca_(2)B_(6)O_(11) + 4SO_(2) + 11H_(2)O rarr 2Ca(HSO_(3))_(2) + 6H_(3)BO_(3)` |
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| 803. |
Orthoboric acid `(H_(3)BO_(3))` commonly known as boric acid behaves as aA. strong monobasic acidB. weak tribasic acidC. weak dibasic acidD. very weak monobasic acid |
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Answer» Correct Answer - D `B(OH)_(3)+2H_(2)O hArr H_(3)O^(+) + [B(OH)_(4)]^(-)` , `pK_(a) = 9.25` It does not donate protons like most inorganic acids but rather it accepts `OH^(-)`. |
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| 804. |
Consider the compounds, `BCl_(3)` and `C Cl_(4)`.How will they behave with water? Justify. |
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Answer» Being a Lewis acid, `BCl_(3)` readily undergoes hydrolysis. Boric acid is formed as a result. `BCl_(3)+3H_(2)Orarr3HCl+B(OH)_(3)` `C"C"l_(4)` completely resists hydrolysis. Carbon does not have any vacant orbital. Hence, it cannot accept electrons from water to form an intermediate. When `C"C"l_(4)` and water are mixed, they form separate layers. `C"C"l_(4)+H_(2)Orarr`No reaction |
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| 805. |
Explain why the following compounds behave as Lewis acids ? (a) `BCl_(3)` (b) `AlCl_(3)` |
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Answer» In trivalent state, the number of electrons around the central atom in a molecule of compounds `BCl_(3)` and `AlCl_(3)` will be only six Such electron deficient molecules have tendency to accept a pair of electron to achieve stable electronic configuration and thus, act as Lewis acids. The tendency to behave as Lewis acid decreases with the increase in the size down the group. |
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| 806. |
Boric acid is an acid because its moleculeA. Contains replaceable `H^(+)` ionB. gives up a protonC. accepts `OH^(-)` from releasing protonD. combines with proton from water molecule. |
| Answer» Correct Answer - C | |
| 807. |
Statement-1: `B(OH)_(3)` behaes as a lewis acid. Statement-2: Second ionisation is very much difficult in boric acid.A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not correct explanation for statement-1C. Statement-1 is true, statement-2 is falseD. Statement-1 is false, statement-2 is true |
| Answer» Correct Answer - B | |
| 808. |
Statement-1: Aluminium chloride has chloro-bridged structure in vapour phase. Statement-2: Aluminium chloride in acidified aqueous solution forms `[Al(H_(2)O)_(6)]^(3+)`A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not correct explanation for statement-1C. Statement-1 is true, statement-2 is falseD. Statement-1 is false, statement-2 is true |
| Answer» Correct Answer - B | |
| 809. |
In the ring test of `NO_(3)^(-)` ion, `Fe^(2+)` ion reduces nitrate ion to nitric oxide, which combines with `Fe^(2+)` (aq) ion to form brown complex . Write the reactions involved in the formation of brown ring. |
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Answer» The chemical reactions involved are : `NO_(3)^(-) (aq)+3Fe^(2+)(aq) +4H^(+)(aq) to NO(g) +3Fe^(3+)(aq)+2H_(2)O(l)` `Fe^(2+)(aq)+NO(g) +5H_(2)O(l) to [Fe (H_(2)O)_(5)NO]^(2+) (aq)` |
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| 810. |
In the ring test of `NO_(3)^(-)` ion, `Fe^(2+)` ion reduces nitrate ion to nitric oxide, which combines with `Fe^(2+)` (aq) ion to form brown complex . Write the reactions involved in the formation of brown ring.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 - C Correct reason. In brown ring test, `Fe^(2+)` ion is oxidises to `Fe^(3+)` ion and `NO_(3)^(-)` reduced to NO. Brown ring test is valid for `Fe_(2)^(+)` ion. |
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| 811. |
`AlF_(3)` is insoluble in anhydrous HF but when little KF is added to the compound it becomes soluble. On addition of `BF_(3),AlF_(3)` is precipitated. Write balanced chemical equation. |
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Answer» `3KF+AlF_(3)toK_(3)[AlF_(6)]` `K_(3)[AlF_(6)]+3BF_(3)toAlF_(3)+3K[BF_(4)]` |
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| 812. |
The percentage of available chlorine in a commercial sampleof bleaching powder isA. 0.12B. 0.35C. 0.58D. 0.85 |
| Answer» Correct Answer - B | |
| 813. |
Describe the manufacture of `H_(2)SO_(4)` by contact process? |
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Answer» Sulphuric acid is manufactured by the contact process. It involves the following steps: Step (i): Sulphur or sulphide ores are burnt in air to form `SO_(2)`. Step (ii): By a reaction with oxygen, `SO_(2)` is converted into `SO_(3)` in the presence of `V_(2)O_(5)` as a catalyst. `2SO_(2(g)) + O_(2(g)) overset(V_(2)O_(5))to 2SO_(3(g))` Step (iii) : `SO_(3)` produced is absorbed on `H_(2)SO_(4)` to give `H_(2)S_(2)O_(7) ` (oleum). `SO_(3)+ H_(2)SO to H_(2)S_(2)O_(7)` This oleum is then diluted to obtain `H_(2)SO_(4)` of the desired concentration. In practice, the plant is operated at 2 bar (pressure) and 720 K (temperature). The sulphuric acid thus obtained is `96-98%` pure. |
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| 814. |
Assertion : HI cannot be prepared by the reaction of KI with concentrated `H_(2)SO_(4)` Reason : HI has lowest H-X bond strength among halogen acids. |
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Answer» Correct Answer - B Correct explanation : Hl formed in the reaction is oxidised to `l_(2)` since it is a strong reducing agent. |
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| 815. |
Formic acid `(HCOOH)` on heating with concentrated `H_(2)SO_(4)` givesA. `CO+CO_(2)+H_(2)O`B. `CO_(2)+H_(2)O`C. `CO+H_(2)O`D. `CO+H_(2)` |
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Answer» Correct Answer - C `underset("Formic acid")(HCOOH)underset(373 K)overset(H_(2)SO_(4))rarrunderset("mononxide")underset(Carbon)(CO)+CO+H_(2)O` |
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| 816. |
Write the conditions to maximize the yield of `H_(2)SO_(4)` by contact process. |
| Answer» The favourable conditions are , low temperature, high pressure and presence of catalyst. | |
| 817. |
Assertion : NaCl reacts with concentrated `H_(2)SO_(4)` to give colourless fumes with pungent smell. But on adding `MnO_(2)` the fumes become greenish yellow. Reason : `MnO_(2)` oxidises HCl to chlorine gas which is greenish yellow. |
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Answer» Correct Answer - A Reason is the correct explanation for assertion. |
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| 818. |
The reactions of `CI_(2)` gas with cold-dilute and hot-concentrated NaOH in water give sodium salts of two different oxioacids of chlorine, P and Q, respectively. The `CI_(2)` gas reacts with `SO_(2)` gas, in presence of charocal, to give a product R reacts with white phosphorus to give a compound S. On hydrolysis, S gives an oxoacid of phosphorus. P and Q, respectively, are the sodium salts ofA. hypochlorous and chloric acidsB. hypochlorous and chlorous acidsC. chloric and perchloric acidsD. chloric and hypochlorous acids. |
| Answer» Correct Answer - A | |
| 819. |
The reactions of `CI_(2)` gas with cold-dilute and hot-concentrated NaOH in water give sodium salts of two different oxioacids of chlorine, P and Q, respectively. The `CI_(2)` gas reacts with `SO_(2)` gas, in presence of charocal, to give a product R reacts with white phosphorus to give a compound S. On hydrolysis, S gives an oxoacid of phosphorus. R, S and T, respectively, areA. `SO_(2)Cl_(2), PCl_(5) and H_(3)PO_(4)`B. `SO_(2)Cl_(2), PCl_(3) and H_(3)PO_(3)`C. `SOCl_(2), PCl_(3) and H_(3)PO_(2)`D. `SOCl_(2), PCl_(5) and H_(3)PO_(4)` |
| Answer» Correct Answer - A | |
| 820. |
In the preparation of `H_(2)SO_(4)` by Contact process, why is `SO_(3)` not absorbed directly in water to form `H_(2)SO_(4)` ? |
| Answer» The process of dissolution of `SO_(3)` in water is so highly exothermic that the acid formed is in the form of thick vapours. These are released as fog. It is of poisonous nature and pollutes the atmosphere. | |
| 821. |
Out of 1 M `H_(2)SO_(4)` and 1 N `H_(2)SO_(4)`, which is more concentrated and why ? |
| Answer» Due to hydrogen bonding | |
| 822. |
Which substance removes `As_(2)O_(3)` in contact process ? |
| Answer» Correct Answer - `Fe(OH)_(3)` | |
| 823. |
`H_(3)PO_(2) " and " H_(3)PO_(3)` act as good reducing agents while `H_(3)PO_(4)` does not. Discuss. |
| Answer» Both `H_(3)overset(+1)(PO_(2)) " and " H_(3)overset(+3)(PO_(3))` can increase the oxidation state of phosphorus upto `+5`. They therefore, act as good reducing agents. However, in `H_(3)PO_(4)`, oxidation state of phosphorus is already `+5` (maximum possible oxidation state). It can act as on an oxidising agent and not as a reducing agent. | |
| 824. |
Out of HClO and HBrO which is a stronger acid ? |
| Answer» Correct Answer - HClO | |
| 825. |
Arrange HClO, HBrO, HIO decreasing order of acidic strength. |
| Answer» `HClO gt HBrO gt HIO` | |
| 826. |
Statement-1: `HNO_(4)` acid never exists. Statement-2: `H_(2)S_(2)O_(3)` is a thionic acid. Statement-3: `H_(2)S_(2)O_(7)` contain S-S bond.A. TFTB. FTFC. FTTD. FFF |
| Answer» Correct Answer - B | |
| 827. |
Assertion : HClO is a stronger acid than HBrO. Reason : Cleavage of ClO-H bond is easier than that of BrO-H bond because Cl is more electronegative than Br.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 - A Reason is the correct explanation for assertion. |
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| 828. |
Asserartion:`PCl_(5)` is covalent in gaseous and liquide states but ionic in solid state. Reason: `PCl_(5)` in solid state consits of tetrahhedral `PCl_(4)^(+)` cation and octahedral `PCl_(6)^(-)` anion.A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not correct explanation for statement-1C. Statement-1 is true, statement-2 is falseD. Statement-1 is false, statement-2 is true |
| Answer» Correct Answer - A | |
| 829. |
Statement-1: Peroxo mono sulphuric acid has low basicity. Statement-2: It has one O-O bond.A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not correct explanation for statement-1C. Statement-1 is true, statement-2 is falseD. Statement-1 is false, statement-2 is true |
| Answer» Correct Answer - B | |
| 830. |
Statement-1: `NH_(3)` is more basic than `NF_(3)` Statement-2: F is more electronegative than H.A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not correct explanation for statement-1C. Statement-1 is true, statement-2 is falseD. Statement-1 is false, statement-2 is true |
| Answer» Correct Answer - A | |
| 831. |
Statement-1: Bond energy of Hl is smaller than that of HBr. Statement-2: HBr is stronger acid than Hl.A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not correct explanation for statement-1C. Statement-1 is true, statement-2 is falseD. Statement-1 is false, statement-2 is true |
| Answer» Correct Answer - C | |
| 832. |
`NF_(3)` is not hydrolysed while `NCl_(3)` can be readily hydrolysed. Explain. |
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Answer» Both nitrogen and fluorine atoms donot have any vacant d-orbitals to accept electron pairs from the oygen atom in `H_(2)O` molecule. Therefore, `NF_(3)` cannot be hydrolysed. However, `NCl_(3)` has vacant d-orbitals on chlorine atoms which can take up electron pairs from `H_(2)O` molecules. As a result, `NCl_(3)` can be hydrolysed. `NCl_(3)+2H_(2)O to NH_(3)+3HClO` |
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| 833. |
Which of the following is not correctly matched?A. `PCl_(5) - sp^(3)d` hybridisationB. `PCl_(3) - sp^(3)` hybridisationC. `PCl_(5)" (solid) "- [PtCl_(4)]^(+) [PtCl_(6)]^(-)`D. `PCl_(5)` - brownish powder |
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Answer» Correct Answer - D `PCl_(5)` is yellowish white powder. |
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| 834. |
Statement-1: `NCl_(3)` is hydrolysed by water by `NF_(3)` is not hydrolysed. Statement-2: N does not has vacant orbital for expansion of octet.A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not correct explanation for statement-1C. Statement-1 is true, statement-2 is falseD. Statement-1 is false, statement-2 is true |
| Answer» Correct Answer - B | |
| 835. |
A translucent white waxy solid (A) reacts with excess of chlorine to give a yellowish white powder (B). (B) reacts with organic compounds containing -OH group converting them into chloro derivatives. (B) on hydrolysis gives (C) and is finally converted to phosphoric acid. (A), (B) and (C) areA. `P_(4), PCl_(3), H_(3)PO_(4)`B. `P_(4), PCl_(5), H_(3)PO_(3)`C. `P_(4), PCl_(5), POCl_(3)`D. `P_(4), PCl_(3), POCl_(3)` |
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Answer» Correct Answer - C `underset((A))(P_(4))+10Cl_(2)rarrunderset((B))(4PCl_(5))` `PCl_(5)+C_(2)H_(5)OHrarrC_(2)H_(5)Cl+POCl_(3)+HCl` `PCl_(5)+H_(2)Orarrunderset((C))(POCl_(3))+2HCl` `POCl_(3)+3H_(2)OrarrH_(3)PO_(4)+3HCl` |
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| 836. |
Consider the following halides : `(I) BF_(3) " " (II) BCl_(3)` `(III) BBr_(3) " " (IV) BF_(3)` The Lewis acid strength of these halides follows the order :A. `I lt II lt III lt IV`B. `I lt III lt II lt IV`C. `IV lt III lt II lt I`D. `IV lt II lt III lt I`. |
| Answer» Correct Answer - A | |
| 837. |
Which one of the following arrangements does not give the correct picture of the trends indicated against it ?A. `F_(2)gt Cl_(2) gt Br_(2) gt I_(2)` : ElectronegativityB. `F_(2) gt Cl_(2) gt Br_(2) gt I_(2)` : Oxizied powerC. `F_(2) gt Cl_(2) gt Br_(2) gt I_(2)` : Electron gain enthalpyD. `F_(2) gt Cl_(2) gt Br_(2) gt I_(2)` : Bond dissociation energy |
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Answer» Correct Answer - 3, 4 Correct order of electron gain enthalpy `underset((-349" kJ"//"mol"))(Cl) gt underset((-333))(F) gt underset((-325))(Br) gt underset((-296))(I)` Correct order of bond dissociation enthalpy of `underset((242.6" kJ"//"mol"))(Cl_(2)) gt underset((192.8))(Br_(2)) gt underset((158.8))(F_(2)) gt underset((151.1))(I_(2))` |
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| 838. |
The hydrolytic reaction of `PCl_(5)` in heavy water yieldsA. `POCl_(3)`B. `DCl`C. `D_(3)PO_(4)`D. All of these |
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Answer» Correct Answer - 4 `{:(PCl_(5)+D_(2)O rarr POCl_(3)+2DCl),(POCl_(3)+3D_(2)O rarr D_(3)PO_(4)+3DCl),(bar(PCl_(5)+4D_(2)O rarr D_(3)PO_(4)+5DCl)):}` |
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| 839. |
Write a balanced equation for the hydrolytic reaction of `PCl_5` in heavy water. |
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Answer» `PCl_(5)+ D_(2)O to POCl_(3) + 2DCl_(2)` `POCl_(3) + 3D_(2) O to D_(3) PO_(4) + 3DCl` Therefore,the net reaction can be written as `PCl_(5) + 4D_(2)O to D_(3) PO_(4) + 5DCl` |
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| 840. |
Write the balanced equation for the hydrolytic reaction of `PCl_(5)` in heavy water. |
| Answer» `PCl_(5)+D_(2)O to POCl_(3)+2DCl` | |
| 841. |
Why is the `BiH_(3)` strongest reducing agent amongst all the hydrides of group 15 ? |
| Answer» Bi-H bond length is the maximum among the hydrides of group 15 elements and bond dissociation enthalpy is the least. Therfore, `BiH_(3)` is the strongest reducing agent amongst all the halides of group 15 elements. | |
| 842. |
Why is `BiH_(3)` the strongest reducing agent amongst all the hydrides of group 15 elements ? |
| Answer» `BiH_(3)` is least stable among group 15 hybrides. | |
| 843. |
Borax bead test is responded by :A. divalent metalsB. heavy metalsC. light metalsD. metals which form coloured metaborates. |
| Answer» Correct Answer - D | |
| 844. |
Which of the following compound is formed in borax bead test ?A. MetaborateB. TetraborateC. TriborateD. orthoborate |
| Answer» Correct Answer - A | |
| 845. |
How many water molecules of crystallisation are present in borax, `Na_(2)B_(4)O_(7).10 H_(2)O` ? |
| Answer» Correct Answer - 8 | |
| 846. |
Boron nitride on reacting with steam givesA. `NH_(3)`B. `N_(2)O`C. `Na_(2)BO_(2)`D. `NO_(2)` |
| Answer» Correct Answer - A | |
| 847. |
Arrange the following molecules in the increasing order of bond angle. `underset(I)(H_(2)O) underset(II)(H_(2)S)underset(III)(H_(2)Se) underset(IV)(H_(2)Te)`A. `H_(2)O gt H_(2)S gt H_(2)Se gt H_(2)Te`B. `H_(2)O gt H_(2) Te gt H_(2)Se gt H_(2)S`C. `H_(2)S gt H_(2)Se gt H_(2)S gt H_(2)Te`D. |
| Answer» Correct Answer - B | |
| 848. |
Which of the following imparts green color to the burner flame?A. `B(OMe)_(3)`B. `Na(OMe)`C. `Al(OMe)`D. `Sn(OH)_(2)` |
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Answer» Correct Answer - A A mixture of ethyl alcohol (or methyl alcohol) with boric acid burns with green edged flame due to the formation of volatile ethyl (or methyl) borate: `H_(3)BO_(3) + 3CH_(3)OH rarr underset("Methyl borate")(B(OCH_(3))_(3))+3H_(2)O` |
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| 849. |
In case of nitrogen, `NCl_(3)` is possible but not `NCl_(5)` while in case of phosphorous, `PCl_(5)` are possible. It is due toA. availability of vacant d-orbitals in P but not in NB. lower electronegativity of P than NC. lower tendency of H-bond formation in P than ND. occurrence of P in solid while N in gaseous state at room temperature. |
| Answer» Correct Answer - A | |
| 850. |
Borax is written asA. `Na_(2)[B_(4)O_(5)(OH)_(4)]*8H_(2)O`B. `Na_(2)B_(4)(OH)_(7)O_(2)*3H_(2)O`C. `Na_(2)OB_(4)O_(8)H_(2)`D. `Na_(2)B_(4)O_(17)H_(2)O` |
| Answer» Correct Answer - A | |