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. |
Steam distillation is based on the fact that vaporisation of organic liquid takes place at |
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Answer» a lower temperature than its boiling point |
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| 2. |
Steam distillation is a better method of purification for … compounds: |
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Answer» Liquids |
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| 3. |
Statues and paintings coated with white lead turn black on long exposure to atmoshphere. The original colour can be restored by treating them with H_(2)O_(2) The reason behind this is |
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Answer» blackened statues get coated with PbS which on reaction with `H_(2)O_(2)`is oxidised to white `PbSO_(4)` `underset("Black")(PbS)+4H_(2)O_(2)RARR underset("White")(PbSO_(4))+4H_(2)O` |
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| 4. |
Starting from phenol how would you obtain the following compounds ? (a) p-quinone, (b) picric acid and (c) Anisole. |
Answer» Solution :(a) Phenol undergoes oxidation with air or acidified `K_(2)Cr_(2)O_(7)` with conc. `H_(2)SO_(4)` to form 1,4-benzoquinone. (b) When phenol reacts with nitrating MIXTURE conc. `H_(2)SO_(4)` and conc. `HNO_(3)`, the product FORMED is PRICE acid. ( c) When phenol reacts with dioz methane in alkaline medium, anisole is formed.
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| 5. |
Statistical thermodynamics is a branch of thermodynamics that deals with the study of_______ of the system. |
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Answer» MICROSCOPIC properties |
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| 6. |
Stating with bromobenzene and any other needed reagents , outlinea synthesis of the following aldehyde. Strategy : Working backward , synthesize the target aldehyde from the corresponding alcohol by oxidation with PCC. Make the alcohol by treating magnesium bromide with oxirane. Notice that adding oxirane to a -CH_(2)CH_(2)OH unit to an organic group. Make phenyl magnesium bromide by treating bromobenzene withmagnesium in an ether solvent. |
Answer» SOLUTION :
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| 7. |
States uses of aluminium, copper, zinc and iron. |
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Answer» Solution :Aluminium : Foils of aluminium are used as wrappers for food materials. The fine dust of the metal is used in PAINTS and lacquers. Aluminium, being highly reactive used in extraction of chromium and manganese from their oxides. WIRES of aluminium are used as electricity conductors. Alloys containing aluminium, being light are very useful. COPPER : Copper is used in making wires used in electrical industry and for water and steam pipes. It is also used in several alloys that are rather tougher than the metal itself, e.g., brass (with zinc), bronze (with tin) and coinage alloy (with nickel). Zinc : Zinc is used for galvanising of iron. It is also used in large quantities in batteries. It is constituent of many alloys, eg., brass, (Cu 60%, Zn 40%) and german silver (Cu 25-30 %, Zn 25-30 %, Ni 40-50 %). Zinc dust is used as a REDUCING agent in the manufacture of dye stuffs and paints, etc. Iron : Cast iron is used for casting stoves, railway sleepers, gutter pipes, toys, etc. It is used in the manufacture of wrought iron and STEEL. Wrought iron is used in making anchors, wires, bolts, chains and agricultural implements. Alloy steel is obtained when other metals are added to it. Nickel steel is used for making cables, automobiles and aeroplane parts, pendulum, measuring tapes. Chrome steel is used for cutting tools and crushing machines and stainless steel is used for cycles, automobiles, utensils, pens, etc.
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| 8. |
Statements : Oxidation ofNa_2SO_3 is not cauysed by air but in presence ofNa_3 AsO-_3 both undego oxidation simultaneously . Explanations : NeitherNaSO_3 norNa_3AO_3 is oxidised by air. |
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Answer» S is correct but E is wrong . |
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| 9. |
Statements: (i) Unit of conductivity is ohm^(-1) cm^(-1). (ii) Conductivity of strong electrolytes decreasews on dilution. (iii) The amount of an ion discharged during electrolysis does not depend upon resistance. |
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Answer» All are correct |
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| 10. |
Statements-I . Ti(III) saltsare coloured whereas Ti(IV) salts are white. Statement-2. Ti(III) is less stable than Ti(IV). |
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Answer» Statement-1 is True, Statement-2 is True, Statement-2 is a CORRECT EXPLANATION of Statement -1 |
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| 11. |
Statements-1. The metals of 4dand 5d transition series have greater enthalpiesof atomisation than thecorresponding elementsof the 3d series. Statements-2. The metal-metal bond in 4d and 5d series are stronger than those in the 3d series. |
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Answer» Statement-1 is TRUE, Statement-2 is True, Statement-2 is a CORRECT EXPLANATION of Statement -1 |
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| 12. |
Statements-1: Linkage isomerism arises in coordination compounds containing amibidentate ligand. Statement-2: Ambidentate ligand has two different donor atoms. |
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Answer» Statement-1 is TRUE, Statement-2 is True , Statement-2 is a CORRECT EXPLANATION for Statement-1. |
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| 13. |
Statement_I: Na_(2)O_(3) is used in Photography. Statement_II: Ag_(2)S_(2)O_(3) is soluble in excess of Hypo solution. |
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Answer» If both Statement-I `&` Statement-II are TRUE `&` the Statement-II is a correct EXPLANATION of the Statement-I |
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| 14. |
Statement1: PCl_(5)hArrPCl_(3)(g)+Cl_(2)(g). Final pressure is more than the initial pressure. Statement2: Deltangt0, more no. of moles on product side. |
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Answer» Statement 1 is true, stetement 2 is true,statement 2 is a correct EXPLANATION for statement 1 `(T&Vto"Contanst").` |
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| 15. |
Statement : To stop bleeding from an injury, ferric chloride can be applied. Which comment about the statement is justified? |
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Answer» If is not TRUE FERRIC chloride is a poison. |
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| 16. |
Statement: The rate of reaction normally increases by a factor of 2 or 3 for evergy 10^(@) rise in temperature. Explanation: Increase in temperature increases the number of collisions. |
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Answer» (a) `S` is correct but `E` is WRONG |
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| 17. |
Statement: The rate of a chemical reaction increases as the temperature is increased. Explanation: The collision frequency between the reactant molecules increases on increasing the temperature. |
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Answer» (a) `S` is correct but `E` is wrong |
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| 18. |
Statement: Photosynthesis in plants involves reaction of CO_(2) and H_(2)O in presence of light and chlorophyll. Explanation: It is chlorophyll which absorbs light and possess this energy to reactant molecules. |
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Answer» (a) `S` is correct but `E` is WRONG |
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| 19. |
Statement: In rate laws, unlike in the expression for equilibrium constants, the exponents for concentration do not necessarity match stoichiometric coefficients. Explanation: It is the mechanism and not the balanced chemical equation for the overall change that governs the reaction rate. |
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Answer» (a) `S` is CORRECT but `E` is wrong |
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| 20. |
Statement-I: Unlike the gtC=O group of aldehydes and ketones, the C=O of R-overset(O)overset(||)C-OH does not undergo nucleophilic addition reactions. Because Statement-II: Carboxylic acids exist as dimers due to intermolecular hydrogen bonding in aprotic medium. |
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Answer» Statement-I is TRUE, Statement-II is True : Statement-II is a CORRECT EXPLANATION for Statement-I |
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| 21. |
Statement-I: When mercuric iodide(s) is added to the aqueous solution of KI, the freezing point is raised. Because Statement-II: HgI_(2) reacts with KI forming complex ion [Hg]_(4)^(2-) |
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Answer» |
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| 22. |
Statement I : Water is a high boiling point liquid. Statement II : Hydrogen bonding in water is responsible for high boiling point of water . |
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Answer» Both the statements individually true and Statement II is the correct explanation of Statement I. |
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| 23. |
Statement-I : There is a natural asymmetry between converting work to heat and converting heat to work. Statement-II : No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work. |
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Answer» Statement-I is TRUE, Statement-II is True, Statement-II is a CORRECT EXPLANATION for Statement-I |
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| 24. |
Statement 1 : The order of extent of attractive forces between monomers is fibres > thermoplastic polymers > elastomers Statement II : Thermoplastic polymers become soft on heating Statement III : Thermosetting polymers become hard on heating Correct statement is/are |
| Answer» Answer :A | |
| 25. |
Statement : The plot of atomic number ( y -axis ) versus number of neutrons ( x -axis ) for stable nuclei shows a curvature towards x-axis fron the line of45^@ slope as the atomic number is increased . Explanation : proton -proton electrostatic repulsions begin to overcome attracive forces involving protons and neutrons in heavier nuclides. |
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Answer» If both Statement-I & Statement -II are True & the Statement -II is a CORRECT explanation of the Statement -I.
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| 26. |
Statement-I: The major products formed by heating with HI are Statement-II: Benzyl carbocation is more stable. |
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Answer» If both statement-I & statement-II are TRUE & the statement-II is a CORRECT EXPLANATION of the statement-I |
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| 27. |
Statement-I: The major products formed by heating with excess HI are: Statement-II: ArSN reaction takes place if the ring is activated by EW (eg., (-NO_(2)) group), at o-,p- and m-position. |
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Answer» <P>If both statement-I & statement-II are true & the statement-II is a CORRECT explanation of the statement-I |
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| 28. |
Statement I : The blue colour of copper sulphate crystal disappers when it is heated strongly. Statement II : Due to heated , water of crystallization of crystal is lost . |
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Answer» Both the statements individually TRUE and Statement II is the correct explanation of Statement I. |
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| 29. |
Statement-I: The boiling pint of diethyl ehter is greater than furan Statement-II: Furan is more compact and has less suface area. |
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Answer» If both statement-I & statement-II are TRUE & the statement-II is a CORRECT EXPLANATION of the statement-I |
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| 30. |
Statement - I : Sulphateisesimated as BaSO_(4) not as MgSO_(4) Statement - I I : onic radius of Mg^(2+) is strallerthan of be^(2+) : |
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Answer» |
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| 31. |
Statement I :The basicity of lanthanides decreases . Statement II : The regular decreasein ionicradiiis lanthanide contraction. |
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Answer» bothassertionand reasonare truereasonis thecorrectexplanationof THEASSERTION . |
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| 32. |
Statement-I: Statement-II: p-NO_(2)-C_(6)H_(4)O^(-) is a stronger nucleophilic than PhO^(-) |
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Answer» If both statement-I & statement-II are TRUE & the statement-II is a correct EXPLANATION of the statement-I |
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| 33. |
Statement-I: Statement-II Phenol cannot be chlorinated because the ring is susceptible to oxidation by Cl_(2). |
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Answer» If both statement-I & statement-II are TRUE & the statement-II is a CORRECT EXPLANATION of the statement-I |
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| 34. |
Statement-I : Standard enthalpy of isomerisation of an anatiomer into the other is zero. Statement-II : The two enantiomers of any chiral compound have the same enthalpy of formation. |
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Answer» If both Statement-I & Statement-II are TRUE & the Statement-II is a CORRECT EXPLANATION of the Statement-I |
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| 35. |
Statement-I : SF_(4) and SeF_(4) are used as fluorinating agent Statement-II : The conversion of -COOH to -CF_(3),C=O to CF_(2) and P = O to PF_(2) can be made by SF_(4) or SeF_(4) |
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Answer» Statement-I and Statement-II are CORRECT and Statement-II is correct EXPLANATION of Statement-I |
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| 36. |
Statement-I:- Sm^(3+), Dy^(3+) have same colour (yellow) Statement-II:-Both ions are having same number of unpaired electrons |
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Answer» STATEMENT I is true, Statement II is true, Statement II is a CORRECT EXPLANATION of Statement I. |
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| 37. |
Statement-I: Relative lowering of vapour pressure is equal to mole fraction of the solvent. Because Statement-II: Relative lowering of vapour pressure is a colligative property. |
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Answer» |
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| 38. |
Statement-I: Reduction potential value (E^(@)) of o-benzoquine (I) is greater than p- benzoquinone Statement-II: Two adjacent (C=O) group in (I) destabilse (I) relative to (II). |
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Answer» If both statement-I & statement-II are TRUE & the statement-II is a CORRECT EXPLANATION of the statement-I |
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| 39. |
Statement I : Oxygen gas is easily produced at a faster rate by heating mixture of potassium chlorate and manganese dioxide than heating potassium chlorate alone . Statement II : Manganese dioxide acts as a negative catalyst . |
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Answer» Both the STATEMENTS INDIVIDUALLY true and Statement II is the correct explanation of Statement I. |
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| 40. |
Statement -I petroleum is mixture of many different hydrocarbons of different densities. Statement -II: The grade of petroleium depends mainly on the relative proportion of the different hydrocarbons |
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Answer» Both the statements are individually true and statement II is the CORRECT EXPLANATION of statement I |
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| 41. |
Statement-I : Number of peroxide bonds in permono and perdisulphuric acid are 1 and 2 respectively Statement-II : Both are dibasic and permonosulphuric acid does not exist in free state but its salts are reducing agent where as perdisulphuric acid salts are oxidant |
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Answer» Statement-I and Statement-II are CORRECT and Statement-II is correct EXPLANATION of Statement-I |
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| 42. |
Statement-I : Of two isomeric alkennes shown, II is more stable than I. Because Statement-II : The alkene (II) has sp^(2)-hybridlzed carbons. |
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Answer» |
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| 43. |
Statement I :Limestone decomposes when it is heated in air . Statement II : Increase in the content of CO_(2) in the atmosphere in recent years is mainly due to the using of limestone in the manufacture of cement. |
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Answer» Both the STATEMENTS are individually true and STATEMENT II is the CORRECT explanation of Statement I |
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| 44. |
Statement I: Metal ions are lewis acids Statement II: Metal ions ae electron pair acceptors |
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Answer» Both the statements individually true and statement II is the correct explanation of statement I |
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| 45. |
Statement-I: Me_(3)C-overset(O)overset(||)(C)-OH+overset(18)(MeOH)overset(conc.H_(2)SO_(4))toMe_(3)C-overset(O)overset(||)(C)-overset(18)(OM)e (Major) Statement-II: During esterification removed water molecule contains H of alcohol and OH of carboxylic acid. |
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Answer» If both statement-I& statement-II are TRUE but statement-II is a correct EXPLANATION of the statement I. |
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| 46. |
Statement-I: is optically inactive, it is taken in a glass container and plane polarized light (PPL) is passed through it after heating it for several minutes The PPL shows significant optical rotation. Statement-II: Like beta-keto acid, gem dicarboxylic acid eliminates CO_(2) on heating. |
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Answer» If both STATEMENT-I& statement-II are TRUE but statement-II is a correct explanation of the statement I. |
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| 47. |
Statement-I:- La^(3+),Lu^(3+) ions are colourless Statement-II:- They do not contain unpaired electrons |
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Answer» Statement I is TRUE, Statement II is true, Statement II is a correct EXPLANATION of Statement I. |
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| 48. |
Statement I : In estimation of FeSO_(4) KMnO_(4) along with HCl can be used as oxidising agent. Statement II : In acidic medium KMnO_(4) is more powerful oxidant compared to neutral/basic medium. |
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Answer» If both Statement-I and Statement-II are TRUE, and Statement-II is the CORRECT EXPLANATION of Statement–I. |
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| 49. |
Statement - I. In electrolysis, the quantity of electricity needed for depositing 1 mole of silver is different form that required for 1 mole of copper. Statement - II. The atomic weights of silver and copper are different. |
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Answer» STATEMENT-1 is TRUE, statement-2 is true and statement2 is CORRECT explanation for statement-4 |
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| 50. |
Statement I : In CuO equivalent weight of Cu is 63.5 & in Cu_(2)O equivalent weight of Cu is 31.8. Statement II :Equivalent weight of any metal is the gm quantity of metal which is combined with 8 gm of oxygen in the formation of metal oxide. |
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Answer» If both Statement-I and Statement-II are TRUE, and Statement-II is the CORRECT EXPLANATION of Statement–I. |
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