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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Both carbonyl compounds and acid derivatives though they contain grouping yet the reactions given by them are entirely different. As Aldehydes andKetones give addition product with a nucleophile, while carboxylic acid derivatives give nucleophilic acyl substitution through addition/elimination mechanism. Where X- = -Cl - O-overset(O)overset(||)C-R-OR, -NR(R) etc. Which of the following is most reactive towards a nucleophile? |
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Answer»
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| 2. |
Both calcination and roasting can be performed in |
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Answer» REVERBERATORY FURNACE |
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| 3. |
both calcination and coasting can be performed in |
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Answer» REVERBERATORY FURNACE |
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| 4. |
Both Br(g) and NO_2(g) are reddish brown gaseous substances. How will you chemically distinguish between them ? |
Answer» SOLUTION :
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| 5. |
Both BF_(3) and NF_(3) are covalent compounds. But BF_(3) is non - polar while NF_(3) is polar. This is because : |
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Answer» atomic size of BORON is smaller than that of NITROGEN |
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| 6. |
Both antacids and antiallergic drugs are antihistamines but they cannot replace each other. Explain why? |
| Answer» SOLUTION :Antacids and antiallergic drugs are ANTIHISTAMINES but they cannot REPLACE each other because both work on different receptors, therefore, antihistamines remove allergy while antacids remove ACIDITY. | |
| 7. |
Both antacids and antiallergic drugs are antihistamines but they cannot replace each other. Explain why ? |
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Answer» Solution :Histamine is a CHEMICAL substance that stimulates the SECREATION of pepsin and hydrochloric acid in stomach. Antacids are designeed to PREVENT theinteraction of histamine with the receptors present in the stomach wall. As a result, less HCl is released in stomach. Histamine contractsthe smooth muscles in the BRONCHI and gut and relaxes other muscles in wallsof fine blood vessels. As a result. As a result, histaine causes allergy. Antihistarnines interfere with the NATURAL action of histamine by competing with histamine for binding sites of receptor where histamine exerts its effect. Since, antiallergic and antacids drugs works on different receptors, therefore, antihistamines remove allergy while antacids remove acidity. |
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| 8. |
Bothaluminium and ironcombineslowly withoxygenatroomtemperature. Why isthisreactionaproblem forironbutnotfor aluminum ? |
| Answer» SOLUTION :AL formsas imperviouscoatof` Al_2O_3 `whichprotectsthemetalfromfurtherecorrosion. In CONTRAST,ironforms ironrust` (Fe_2O_3.xH_2O)`whichflakesoffexposingfreshsurfaceto CORROSION. | |
| 9. |
Both methanol and ethanol give iodoform test.true or false |
| Answer» SOLUTION :Only ethannot GIVES IODOFORM TEST. | |
| 10. |
Both alcohol and ether having same molecular formula ether is more volatile than alcohol, why ? |
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Answer» PRESENCE of INTERMOLECULAR H-bond in ALCOHOL |
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| 11. |
Both acetaldehyde and acetone reacts with |
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Answer» TOLLEN's reagent |
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| 12. |
Borontrifluoride reacts with sodium hydride at 450 K gives………….. |
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Answer» diborane |
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| 13. |
Boron was isolated by : |
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Answer» Davy |
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| 15. |
Boron shows single oxidation state due to absence of |
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Answer» inert PAIR effect |
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| 16. |
Boron reacts with fused sodium hydroxide to forms……………… |
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Answer» Borax |
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| 17. |
Boron + O_(2) overset(700^@C)(rarr)(X) (X) + C("carbon") + Cl_2 + (Y) + CO (Y) + LiAlH_4 to (Z) + LiCl + AlCl_3 Compound (Z) is |
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Answer» an ionic compound |
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| 18. |
Boron nitride on reacting with caustic alkali gives: |
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Answer» `NH_3` |
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| 19. |
Boron Nitride, Diamond, Silicon Carbide are examples of which type of solids |
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Answer» COVALENT Solids |
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| 20. |
Boron is unable to form BF_(6)^(3-) because of |
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Answer» High electronegativily of boron |
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| 21. |
Boron is found in form of: |
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Answer» Borax |
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| 22. |
Boron has two isotopes boron-10 and boron-11 whose percentage abundanes are 19.6% and 80.4% respectively. What is the average atomic mass of boron? |
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Answer» SOLUTION :Contribution of boron -10=`10.0xx0.196=1.96` AMU Contribution of boron-11 `=11.0xx0.804=8.844` amu LTBR. ADDING both =1.96+8.844=10.804 amu |
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| 24. |
Boron halides behave as Lewis acids, because of their |
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Answer» Ionic nature  (Deficiency of two electron for INERT configuration)
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| 25. |
Boron does not react directly with hydrogen. Suggest one method to prepare diborane from BF_(3). |
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Answer» Solution :(i) Boron does not react directly with hydrogen. However, it forms a variety of hybrides called boranes. (II) The simplest borane is DIBORANE - `B_(2)H_(6)`. Other larger boranes can be prepared from diborane. (iii) Treatment of gaseous boron trifluoride with sodium hybride around 450 K gives diborane. To prevent subsequent pyrolysis, the product diborane is trapped IMMEDIATELY. `2BF_(3) + 6NaH overset(450K)to B_(2)H_(6) + 6NaF` |
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| 27. |
Boron differs from the other members of group 13 because it : |
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Answer» It is a non-metal |
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| 28. |
Boron compounds behave as Lewis acids because of their : |
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Answer» ACIDIC nature |
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| 29. |
Boron compounds behave as lewis acid because of their _____________ |
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Answer» IONISATION property |
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| 30. |
Boron carbide,B_4C is widely used for : |
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Answer» MAKING acetylene |
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| 32. |
Born-Haber cycle is used to determine |
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Answer» CRYSTAL energy |
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| 33. |
Born haber cycle cannot be used to estimate |
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Answer» Electronegativity |
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| 34. |
Boric acids has a …………………….. Structure. |
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Answer» |
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| 35. |
Born-Haber cycle can be used to estimate: |
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Answer» LATTICE ENERGY of IONIC crystals |
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| 37. |
Boric acid is prepared from borax by the action of : |
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Answer» HYDROCHLORIC acid |
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| 38. |
Boric acid is polymeric due to |
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Answer» its ACIDIC nature |
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| 39. |
Boric acid is polymericdue to |
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Answer» its acidic nature |
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| 40. |
Boric acid is not used as : |
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Answer» As a flux in SOLDERING |
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| 41. |
Boric acid is anacid because its molecule |
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Answer» acceptsoh from water releasing proton |
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| 42. |
Boric acid is an acid because its molecule …………. |
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Answer» contains replaceable `H^(+)` ion Hint : `B(OH)_(3) + H_(2) O hArr [B(OH)_(4)] + H^(+)` |
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| 44. |
Boric acid in water produces ? |
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Answer» `H_(2)BO_(3)^(-)` |
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| 46. |
Boric acida dilute solution is used as : |
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Answer» ANTIBIOTICS |
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| 47. |
Boric acid : |
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Answer» exists in polymeric form due ot inter-molecular HYDROGEN bonding |
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| 48. |
Borazine and benzene show striking similarities in their properties. This led to a labelling of borazine as 'inorganic benzene'. However, in contrast to benzene, borazine readily undergoes addition reactions. The appropriate reason for this difference is: |
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Answer» Alternate arraangement of `B` and `N` atoms in the hexagonal RING. |
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| 49. |
Borax when heatedon platinum wire forms a glass - like bead which is made up of : |
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Answer» SODIM tetraborate |
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