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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. |
What is effect of : (i) addition of H_2 (ii) addition of CH_(3)OH (iii) removal of CO (iv) removal of CH_(3)OH On the euilibrium 2H_(2)(g) + CO(g) hArr CH_(3)OH(g) |
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Answer» EQUILIBRIUM will be SHIFTED in the FORWARD DIRECTION. |
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| 2. |
Under what condition can the process of steam distillation be used ? |
| Answer» Solution :The process of STEAM distillation can ve used to purify the LIQUID which is steam VOLATILE in NATURE i.e., it gives sufficient vapours at the boiling point of water. Moreover, the liquid and water should not be MISCIBLE with each other. | |
| 4. |
Why alkyl halides are generally not prepared in the laboratory by free radical halogenation of alkanes? |
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Answer» Solution :Free radical halogenation is not suitable method for laboratory PREPARATION of alkyl halides because of the following reasons : (i) Because of the presence of different types of hydrogen atoms present in alkanes they give a mixture of isomeric monohalogenated PRODUCTS whose BOILING points are so close that they cannot be easily separated in the laboratory. (ii) SUBSTITUTION of more than one hydrogen ATOM yields polyhalogen compounds making the mixture more complex and hence difficult to separate. |
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| 5. |
When ammonia combines with HCl,NH_(4)Cl is formed as white dense fumes. Why do more fumes appear near HCl? |
| Answer» Solution :`NH_(3)` having lower molar mass will diffuse FASTER and hence travel a greater length of the tube hence more fumes APPEAR near HCL. | |
| 6. |
Which in each pair of elements has a more negative electron gain enthalpy? (a) F or Cl^- ,( b) O or O^-,( c) Na^+or S , ( d) F or F^- |
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Answer» |
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| 7. |
Which of the following used in CLARK method to remove temporary hardness of water ? |
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Answer» `Na_2CO_3` |
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| 8. |
Which alkali metal element having percentage proportion of 4% in earth crust? |
| Answer» Answer :C | |
| 9. |
Xlitre of carbon monoxide is present at mSTP. It is completely oxidised toCO_2 . Formed is 11.207 l. What is the vlue of X in litres? |
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Answer» `22.414` |
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| 10. |
What doesatomicradiusor ionicradiusmean toyou ? |
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Answer» Solution :Atomicradiusliterallymeanssize ofthe atom. It can be measured either by X- ray orby spectroscopic METHODS. In caseof NON- metals atomicradiusis calledcovalent radius. It isdefinedas one - half thedistancebetweenthe nuclei of TWO covalently bondedatomsof thesameelementin a molecule. Forexamplethe internucleardistancebetweentwochlorineatoms inchlorinemolecule is 198pm. Therefore, the covalent radiusof chlorineatom is198`//`=99pm (0.99 A) . In caseof metals atomicradiusis calledmetallicradius . It isdefinedas one - half thedistancebetweenthe twoadjacentatoms in the crystal lattice .Forexamplethe distancebetweentwoajdacent copper atom in solidcopperis 256 pm,thereforethe metallicradiusof copper is 256`//`2 = 128pm (1.28 A) Ionic radius means size of the ion. An ion can be acation or an anion. The sizeof acationis always smaller than thatof the parentatombecauseloss ofone ormoreelectrons increasesthe effective nuclearcharge. As aresultforce of attractionincreasesand hencethe ionicsizedecreases . On theother hand the size of theanionis always largerthan the parent atom because the additionof one or more electronsdecreasesthe effectivenuclearcharge . As a result the force ofattractiondecreases and hencethe ionic sizeincreases.for examplethe ionic radiusof `Na^(+)` is 95pm whiletheatomicradiusof sodium is 186 pm. One the other handionicradius of fluorideion in136 pmwhereas the atomic radiusof fluorine atom isonly 72pm. |
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| 11. |
Which in each pair of elements has a more negative electron gain enthalpy? Explain. |
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Answer» a) N or O |
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| 12. |
What volume of H_(2) at NTP is required to convert 2.8 g of N_(2) into NH_(3)? |
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Answer» 2240 ml `28grarr3xx22.4` lit `2.8g RARR? =3xx22.4xx0.1=6.72` lit |
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| 13. |
Which metal element is not solid ? |
| Answer» SOLUTION :MERCURY (HG) is not SOLID. It is LIQUID in normal temperature. | |
| 14. |
What is polymerisation ? Write the example and uses of the reaction. |
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Answer» Solution :(a) definition : Polythene is OBTAINED by the combination of large number of ethene moelcules at HIGH temperature, high pressure and in the presence of a catalyst. The large molecules thus obtained are called polymers. This reaction is known as polymerisation. (b) Example :(i) POLYMERIZATION of ethelene, forms polyethelene. `underset("Ethene")(nCH_(2)=CH_(2))underset("High pressure, catalyst")overset(473-673, O_(2) " High temperature")rarr underset("Polyehene")((-CH_(2)-CH_(2)-)_(n))` (ii) Polymerization of propelene, yields propelene polymer. `underset("Ethene")(nCH_(3)-CH=CH_(2))underset("High pressure, catalyst")overset("High temperature")rarr underset("Polypropene")((-overset(CH_(3))overset(|)(CH_(2))-CH_(2)-)_(n))` (c) Uses : POlymers are USED for the manufacture of plastic bags, squeeze bottles, refrigerator dishes, toys, pipes, radio and T.V. cabinets etc. Polypropeneis used for the manufacture of milk crates, plastic buckets and other moulded articles. Limitations : Though these materials have now become COMMON, excessive use of polyethene and polypropylene is a matter of great concern for all of us. |
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| 15. |
The shape of molecule is depend on which factor? |
Answer» SOLUTION :To DECIDE shape-geometry of ORGANIC compound, it is necessary to known the TYPES of HYBRIDISATION 
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| 17. |
Which of the following pollutant is released from the emissioin tuhes of diesel engines |
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Answer» MERCURY |
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| 18. |
Which of the following hydrogen compounds is most ionic ? |
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Answer» LiH |
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| 19. |
The volume of 0.025M Ca(OH)_(2) solution which can neutralise 100 ml of 10^(-4)M H_(3)PO_(4) is |
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Answer» 10ml |
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| 20. |
Which of the following compounds will not undergo Friedel-Crafts reaction only ? |
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Answer» Nitrobenzene |
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| 21. |
Which one of the following will not show geometrical isomerism ? |
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Answer»
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| 22. |
What do you understand by the term 'non stoichiometric hydrides? Do you expect this type f hydrides to be formed by alkali metals? Justify your answer, |
| Answer» Solution :These HYDRIDE which do not have FIXED composition are called non-stoichiometric hydride and the composition varies with temperature and pressure This type of HYDRIDES are FORMED by d and f-block ELEMENTS. They cannot be formed by alkali metals because alkali metal hydrides form ionic hydrides. | |
| 23. |
What is electrical conductivity due to in (a) metals,(b)ionic solids, and © semiconductors ? |
| Answer» Solution :(a) DUE to flow of electrons. (b) Due to flow of IONS in solution or MELT and defects in the solid STATE. (c ) Due to the PRESENCE of impurities and defects. | |
| 24. |
What is polyprotic acid ?Give example of polyprotic acid and its ionization. |
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Answer» Solution :Polyprotic ACID : The ACIDS which have more than one ionizable proton per molecule of the acid. Such acids are known as polybasic or polyprotic acids. DIPROTIC acid : The acid which have two ionizable proton per molecule of the acid. Such acids are known as Dibasic or Diprotic acid e.g., `H_2X_((aq)) +hArr 2H^(+) + X^(2-) ,K_a` The ionization of the reaction is in two steps is as under , (i) `H_2X+ H_2O hArr H_3O^(+) + HX^(-) "" K_a`(i) (ii)`HX^(-) + H_2O hArr H_3O^(+) + X^(2-) "" K_a` (ii) In it, `K_a (i) gt K_a (ii)` and `K_a (i) xx K_a (ii) = K_a` Examples of diprotic acid :Oxalic acid `(H_2C_2O_4)`, Sulphuric acid `(H_2SO_4)` , Carbonic acid `(H_2CO_3)` , Sulphurous acid `(H_2SO_3)` ,Ascorbic acid etc. Examples of triprotic acid : PHOSPHORIC acid `(H_3PO_4)`, Cytaric acid .... etc. In polyprotic acid solutionconstant MIXTURE of acid like `H_2A, HA^(-)` and `A^(2-)` |
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| 25. |
The work done in adiabatic compression of 2 mole of an ideal monoatomic gas by constant external pressure of 2 atm starting from initial pressure of 1 atm and initial tempreature of 1 atm and initial temperature of 300 K. (R=2 cal//mol-degree) |
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Answer» 360 cal |
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| 26. |
Which of the following reactions is not correct according to the law of conservationof mas? |
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Answer» 2Mg(s) + `O_(2)`(s) `to` 2MgO(s)` Correct equation is `C_(3)H_(8)(g) + 5O_(2)(g) to 3CO_(2)(g) + 4H_(2)O(g)` |
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| 27. |
The weight of MgCO_(3) required for the preparation of 12g of MgSO_(4) by reacting with sulphuric acid is |
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Answer» 8.4g |
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| 28. |
The simplest pair of compounds exhibiting functional group isomerism have a minimum of |
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Answer» FOUR CARBONS |
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| 29. |
Which among the following statement/s given below is/ are incorrect regarding hydrogen? 1) It is diatomic in nature. 2) Has only one electron in the outermost shell 3) Very good oxidizing agent 4) Does not form hydrides easily |
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Answer» 1,2,& 3 |
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| 30. |
What transition in the hydrogen spectrum would have the samewavelength as the Balmer transition n = 4 to n = 2 of He^(+)spectrum? |
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Answer» |
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| 31. |
Why "CCl"_(4) is resistantto hydrolysisbut SiCl_(4) is readily hydrolysed? |
| Answer» Solution :Due to presenceof vacantd-orbitals in Si, `SiCl_(4)`accepts a lone pair of electronsdonatedby `H_(2)O` moleculeand hence UNDERGOES hydrolysis. Howoverdue to absence of d-orbitalsin `C, "CC"l_(4)` cannot a accepta pair of ELECTRONS from water moleculesand hence does notundergohydrolysis. | |
| 32. |
What is ortho hydrogen? |
| Answer» Solution :Hydrogen MOLECULE in which protons in the NUCLEI of both H-atoms are known to SPIN in same DIRECTION is termed as ortho hydrogen. | |
| 33. |
Which of the following represents calgo? |
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Answer» `Na_(2)AI_(2)Si_(2)O_(8)` |
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| 34. |
Whay does benzene behave like a saturated hydrocarbon? |
| Answer» SOLUTION :Because of RESONANCE EFFECT. | |
| 35. |
underset("(A)(B)"){:(""CH_(3)""CH_(3)-Br),("||"),(CH_(3)-C-CH_(3)+CH_(3)-CH-CH_(3)),("|"),(""Br):} CH_(3)-overset(CH_(3))overset("|")"CH"-CH_(3)overset(Br_(2))rarr the percentage yeild of 'A' is (The relative reactivities of 1^(@), 2^(@), 3^(@)- hydrogens are 1:3.8:5) |
| Answer» ANSWER :A | |
| 36. |
Which of the following reactions is an example of Bouveault Blanc reduction ? |
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Answer» `CH_(3)CN underset(C_(2)H_(5)OH)overset(Na)rarrCH_(3)CH_(2)NH_(2)` |
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| 37. |
Which property is lower for deuterium than hydrogen |
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Answer» LATENT HEAT of vapourisation `H_(2):D_(2):T_(2)::2:4:6` |
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| 38. |
Which of the following is relatively stronger base? P^(kb)values are given in brackets. |
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Answer» `AOH (5.8)` |
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| 39. |
Water pollution is mainly due to |
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Answer» Suphur dioxide |
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| 40. |
The total number of electrons present in 18 mL of water (density of water is 1 g mL^(-1) is: |
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Answer» `6.02 xx 10^(23)` |
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| 41. |
What is the equivalent mass of KIO_3in the given reaction ? KIO_3 + 2KI + 6HCI rarr 3lCl+ 3KCl + 3H_(2)O |
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Answer» 214 `E =(M)/4 = (214)/4 = 53.5` |
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| 42. |
Which of the following has highest mass? |
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Answer» One GRAM ATOM of Iron |
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| 43. |
What is the concentration of pure water and ions ? |
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Answer» SOLUTION :CONCENTRATION of water = 55.55 M concentration of ion `[H^+]=[OH^-]=1xx10^(-7)` M |
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| 44. |
Which type of hybridization of the central atom in the following ? PCl_(5) , SF_(6), "CCl"_(4), NH_(3) , BeCl_(2) , CO_(2) , BH_(3), BCl_(3) |
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Answer» Solution :`(i) PCl_(5) : sp^(3) d"(iv)" BeCl_(2) , CO_(2) : sp` (ii) `SF_(6) : sp^(3) d^(2)"(v)" BH_(3), BCl_(3) : sp^(2)` (iii) `"CCL"_(4) , NH_(3) : sp^(3)` |
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| 45. |
ZnI_2, can be prepared by the direct combination of elements. A chemist determines from the amounts of elements that 0.0654 mol ZnI_2 can be formed. |
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Answer» Solution :The molar mass of `ZnI_2` is 319 g/MOL. (The formula weight is 319 amu, which is OBTAINED by summing the ATOMIC weight in the formula) THUS `0.0654 ` mol `ZnI_2 xx (319g ZnI_2)/(1 "mol " ZnI_2)` `=20.9 "gm "ZnI_2` |
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| 46. |
Write the IUPAC name by using systematic names for alkyl groups : (i) 4-isopropyldecane (ii) 5-t-butyldecane (iii) 4-t-butyl-2,6-dimethyldecane (iv) trans-butyl-3-isopropyl cyclobutane (v) 4-isopropyl-2-octene (vi) 4-tert-butyl-2,5-dimethyloctane (vii) 4-methyl-4-isopropenyl-1-cyclohexene (viii) 3-isobutyl 1,4-hexadiyne. |
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Answer» Solution :(i) 4-(1-methylethyl) decane (ii) 5-(1,1-dimethylethyl) decane (iii) 4-(1,1-dimethylethyl)-2,6-dimethyldecane (iv) trans-(1-methylpropyl)-3-(1-methylethyl)-cyclobutane (v) 4-(1-methylethyl)-2-octene (vi) 4-(1,1-dimethylethyl)-2,5-dimethyloctane (vii)1-methyl-4-(1-methylethenyl)1-cyclohexene (viii) 3-(2-methylpropyl)-1,4-hexadiyne. |
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| 47. |
To get n-type doped semiconductor, impurity to be added to silicon should have the following number of valence electrons |
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Answer» 2 |
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| 48. |
Which one is not a pollutant normally? |
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Answer» Hydrocarbons |
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| 49. |
Thermodynamically the most stableform of carbon is (a) diamond, (b) graphite, (c ) fullerees , (d) coal |
| Answer» Solution :Thermodynamicallythe most stableform of carbon is GRAPHITE, i.e, OPTION (B) is CORRECT. | |
| 50. |
What is overlapping of atomic orbitals ? When the bond is formed ? |
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Answer» Solution :In molecule two atoms remain closer to each other so that the SYSTEM get minimum energy state. Their atomic ORBITAL undergo PARTIAL interpenetration. This partial merging of atomic orbitals is called overlapping of atomic orbitals, which results in the pairing of electrons. The extent of overlap decides the strength of a covalent bond. Greater the overlap the STRONGER is the bond, formed bond two atoms. The formation of a covalent bond between two atoms results by pairing of electrons present in the valence SHELL having opposite spins. |
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