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. |
Write two basic properties of electric charge. |
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Answer» (i) Charge is quantised that is charge Present on any object will always be the integral multiple of charge present on each electron. Q = ne (ii) Charge is conserved |
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| 2. |
What is the value of i in the given circuit? |
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Answer» According to Krichhoff's junction rule Total incoming current = Total outgoing current 2A + 7A + 5A = 3A + i 14A = 3A + i i = 14A - 3A = 11A. |
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| 3. |
In which reactions, correct stereo chemistry of product is mentioned ?A. B. C. D. |
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Answer» Correct Answer - A,B,C,D (A)trans+Anti addition `to` Meso compound , (B)Trans+SYN addition `to` Racemic mixture (C )Cis + Anti addition `to` Racemic mixture , (D)Trans+SYN addition `to` Racemic mixture. |
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| 4. |
When light travels travels one medium to another which of the following factors changes?(a) Wavelength(b) Frequency(c) Speed(d) Amplitude. |
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Answer» Correct answer is (a,c,d) |
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| 5. |
Both the `C_(beta)-H and C_alpha-X` bonds are breaking in the transition state of E2 reactions.The rate of E2 reactions is of second order.The rate shows primary isotopic (dueterium) effect. i.e. if `C_beta-H` is replaced by `C_beta-D` , the rate of reaction decreases sharply. The rate is also corelated with nucleofugality i.e. the ability of leaving group to leave.With a better nucleofuge, the rate of reaction increases.This is called he element effect. The element effect is also observed in E1cB reactions in which the second step is rate determining and elimination of first order w.r.t conjugate base is observed.For E1cB reaction `K_H//K_D=1`, therefore proton abstraction is not involved in the rate determing step In `D_2O` the incorporation of Deuterium at `C_beta`-H in the In E1 reaction only nucleofuge departs in slow step and a carbocation intermediate is formed. For the given compounds I and II the rate of elimination by `EtO^(Theta)//EtOH` shows `K_H//K_D=7.1` What is the about this reaction A. Both `C_(beta)-H` and `C_alpha-Br` bonds are breaking simultaneously in transition stateB. Only `Br^(Theta)` is eliminated in rate determining stepC. Only `H^(Theta)` or `D^(o+)` is eliminated in rate determining stepD. the reaction intermediate is resonance stabilized |
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Answer» Correct Answer - A The breaking of `C_beta-H` is faster than `C_beta-D` and both `C_beta-H` and `C_alpha-Br` are breaking in same step. It is an E2 reaction. |
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| 6. |
Both the `C_(beta)-H and C_alpha-X` bonds are breaking in the transition state of E2 reactions.The rate of E2 reactions is of second order.The rate shows primary isotopic (dueterium) effect. i.e. if `C_beta-H` is replaced by `C_beta-D` , the rate of reaction decreases sharply. The rate is also corelated with nucleofugality i.e. the ability of leaving group to leave.With a better nucleofuge, the rate of reaction increases.This is called he element effect. The element effect is also observed in E1cB reactions in which the second step is rate determining and elimination of first order w.r.t conjugate base is observed.For E1cB reaction `K_H//K_D=1`, therefore proton abstraction is not involved in the rate determing step In `D_2O` the incorporation of Deuterium at `C_beta`-H in the In E1 reaction only nucleofuge departs in slow step and a carbocation intermediate is formed. Observe the given reaction, In this reaction `K_H//K_D=1` What is not true about this reaction A. B. C. In`EtO^(Theta)//EtOH`,H exchange will be observedD. In `EtO^(Theta)//EtOH` the rate of reaction will be faster as compared to `EtO^(Theta)//EtOD` |
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Answer» Correct Answer - D Both EtOH or EtOD give same base `EtO^(Theta)` so rate of reaction will be same this is an E1cb reaction. |
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| 7. |
Which among the following rays is not deflected by electric field ?(a) X-ray(b) Y-ray(c) α -ray (d) Cathode ray |
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Answer» Correct answer is (a,b) |
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| 8. |
Among the following whose mass is not equal to the mass of'an electron?(a) Proton(b) Hydrogen(c) Positron(d) Neutron |
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Answer» Correct answer is (a,b,d) |
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| 9. |
There are two columns. Column-I contains You have to match the correct options of these questions as (a) (b), (c) and (d) from Column-II. Column-IColumn-II(i) Brewster's law (a) Interference(ii) Liquid lens(b) Defect of image(iii) Chromatic Aberration(c) Polarisation(iv) Young's double slit experiment(d) Human eye |
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Answer» (i) (c) (ii) (b) (iii) (b) (iv) (a) |
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| 10. |
Hydrolysis of cumene hydroperoxide is an important reaction in organic chemistry.This reaction involves migration of phenyl group to electron deficient oxygen. Another reaction which involves group migration is the Schmidt reaction, in which isocyanide intermediate is formed. `RCOOHunderset((ii)NaN_3)overset((i)PCl_5)toR-undersetunderset(O)(||)C-N_3overset(Delta)toR-N=C=O("Isocyanate")overset(EtOH)toRNHCOOC_2H_5` Now consider the following scheme of reaction and answer the following questions. (i)+CH_3CH=CH_2overset(H^+)toXoverset(H^+ // K_2Cr_2O_7)toYunderset((ii)NaN_3)overset((i)PCl_5)toZoversetDeltatoWoverset(C_3H_7OH)toP` (ii)`Xunderset((ii)H_3O^+)overset((i)O_2)toX_1+(CH_3)_2C=O` The product P should beA. `C_6H_5OH`B. `C_6H_5NHoversetoverset(O)(||)C-NH_2`C. `C_6H_5NH-oversetoverset(O)(||)C-NHC_3H_7`D. `C_6H_5NHCOOC_3H_7` |
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Answer» Correct Answer - D `C_6H_5-N=C=Ooverset(C_3H_7OH)toC_6H_5-NHCOOC_3H_7` |
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| 11. |
In the following sequence of reactions all stereoisomers of (X) have been taken. Find the Total number of products (Z) formed. |
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Answer» Correct Answer - 4 X has 3 stereocentres with similar ends.Hence, 6 stereoisomers . `Y=CH_3-undersetunderset(D)(|)CH-CHO` has one sterteocentre, hence 2 stereoisomers . `Z=CH_3-undersetunderset(D)|CH-CH=NOH` has 2 stereocentres , hence 4 stereoisomers. |
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| 12. |
If 18 g of Glucose is present in 1000 g of solvent, the solution is said to be – (A) 1 Molar (B) 0.1 Molal (C) 0.1 Molar (D) 0.5 Molal |
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Answer» Correct answer is (B) 0.1 Molal |
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| 13. |
Molarity is expressed as – (A) Mol/litre (B) g/litre (C) litre/mol (D) mol/kg |
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Answer» Correct answer is (A) Mol/litre |
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| 14. |
Which is not correct with respect to p-toluene sulphony chloride?(a) It is hinsberg's reagent(b) It forms a ppt which is soluble with alkali(c) Used to distinguish primary and secondary amines(d) Tertiary amines do not react with it |
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Answer» (b) It forms a ppt which is soluble with alkali It forms a ppt which is soluble with alkali only in case of primary amines. |
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| 15. |
The strongest base among the following is:-A. B. C. D. |
| Answer» Correct Answer - C | |
| 16. |
The strongest base among the following is:-A. B. C. D. |
| Answer» Correct Answer - C | |
| 17. |
In the reaction `CH_(3)COOHoverset(LiAlH_(4))rarr(A)overset(I_(2)+NaOH)rarr(B)overset(Ag("Dust"))rarr(C)`, the final product C is:-A. `C_(2)H_(5)I`B. `C_(2)H_(5)OH`C. `C_(2)H_(2)`D. `CH_(3)COCH_(3)` |
| Answer» Correct Answer - C | |
| 18. |
Bond dissociation enthalpy of E—H (E = element) bonds is given below. Which of the compounds will act as strongest reducing agent? |
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Answer» The compounds will act as strongest reducing agent are given below (d) SbH3 |
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| 19. |
On mixing, heptane and octane form an ideal solution. At `373K` the vapour pressure of the two liquid components (heptane and octane) are `105 kPa` and `kPa` respectively. Vapour pressure of the solution obtained by mixing `25.0` of heptane and `35g` of octane will be (molar mass of heptane `= 100 g mol^(-1)` and of octane `= 114 g mol^(-1))`:-A. `61.2 kPa`B. `36.1kPa`C. `96.2kPa`D. `144.5kPa` |
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Answer» Correct Answer - 1 `P_(T)=X_("Heptane")P_("Heptane")^(@)+X_("Octane")^(@)P_("Octane")^(@)` `=(0.25)/(0.557)xx75+(0.307)/(0.557)xx50` `33.66+27.558=61.2kPa` |
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| 20. |
The volume occupied by atoms in a simple cubic unit cell is `: ( `edge length `=a)`A. `a^(3)`B. `(4pia^(3))/(3)`C. `(pia^(3))/(6)`D. `(sqrt(3)pi)/(8)` |
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Answer» Correct Answer - 3 In simple cubic `a=2r` volume `=(4)/(2)pi r^(3)=(4)/(3)pi((a)/(2))^(3)=(1)/(6)pi a^(3)` |
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| 21. |
Percentage of packing fraction in cubic close packed structure and in body centered packed structure are respectively.A. `74%` and `68%`B. `26%` and `32%`C. `32%` and `48%`D. `48%` and `26%` |
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Answer» Correct Answer - 1 Packing fraction of CCP `=(pi)/(3sqrt(2))=0.74" "74%` Packing fraction of BCC ` = (pisqrt(3))/(8)=0.68implies68%` |
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| 22. |
ΔHcombustion of a compound is(a) positive (b) negative (c) zero (d) positive or negative |
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Answer» (b) negative |
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| 23. |
Which of the following statement is incorrect ?A. `FeSiO_(3)` is obtained as slag in the extraction of iron from haematite ore.B. In Hall`-` Heroult process, the electrolyte used in a molten mixture of alumina and cryolite.C. Lead is extracted form its chief ore galena by both carbon reduction as well as self reduction.D. Boron is obtained by thermal decomposition of `BI_(3)`. |
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Answer» Correct Answer - 1 `(1) " "FeSiO_(3)` is obtained as slag in the metallurgy of copper from pyrites. `(2)` Electrolysis is molten alumina dissolved in cryolite. (3)` 2PbS+3O_(2)rarr 2PbO+2SO_(2)` `PbS+2PbOrarr3Pb+SO_(2)("self reduction")," "PbO+C rarrPb+CO("carbon reduction")` `(4)" "2BI_(3)overset(Delta)rarr 2B+3I_(2)("Van Arkel method")` |
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| 24. |
Which of the following statements is incorrect ?A. Ammonium salts on reaction with strong alkalies produce a non`-` inflamable gas.B. fac`- [Co(NO_(3))_(2)("dien")]` is non`-` chiral.C. Solid potassium dichromate and concentrated `H_(2)SO_(4)` liberates chlorine gas with solid sodium chloride.D. The increasing order of paramagnetic properties amongst `VCl_(3),VOSO_(4),Na_(3)VO_(4),[V(H_(2)O)_(6)]SO_(4).H_(2)O` is `Na_(3)VO_(4) lt VOSO_(4) lt VCl_(3) lt [V(H_(2)O)_(6)]SO_(4).H_(2)O.` |
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Answer» Correct Answer - 3 `(1)" "NH_(4)^(+)+OH^(-)rarrNH_(3)uarr +H_(2)O` `(2)` The statements is correct, non`-` chiral because there is mirror plane through the metal bisecting the dien ligant. `(3)" "4Cl^(-)(s)+Cr_(2)O_(7)^(2-)(s)+6H^(+)("conc.")rarr2CrO_(2)Cl_(2)uarr("deep red")+3H_(2)O(l)` `(4)" "VCl_(3),._(23)V^(3+),[Ar]^(18)3d^(2)=2` unpaired electrons. `VO^(2+),V^(4+),[Ar]^(18)3d^(2)=1` unpaired electron. `[VO_(4)]^(3-),V^(5+),[Ar]^(18)3d^(0)=` no unpaired electron. `[V(H_(2)O)_(6)]^(2+),V^(2+):[Ar]^(18)3d^(3)=3` unpaired electrons. |
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| 25. |
An organic compound gives blood red colouration with Victor-Maeyer’s test. When this compound vapour is passed through Cu-tube at 300°C produces(a) Aldhyde(b) Ketone(c) Carboxylic acid(d) Benzene |
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Answer» Aldhyde compound vapour is passed through Cu-tube at 300°C produces. |
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| 26. |
The compound with negative heat of formation is known as (a) endothermic compound (b) exothermic compound (c) endoergonic compound (d) none of the above. |
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Answer» (b) exothermic compound |
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| 27. |
Sodium is heated with ammonia gas, the produced compound is-(a) Na3N(b) NaNH2(c) H2N – NH2(d) N3H |
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Answer» Sodium is heated with ammonia gas, the produced compound is NaNH2 |
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| 28. |
The reaction is called:(a) Cannizzaro Reaction(b) Rosenmund's Reaction(c) Haloform Reaction(d) Clemensen's Reaction |
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Answer» Answer is (d) Clemensen's Reaction |
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| 29. |
Tollen’s reagent is used for detecting-(a) Aldehyde(b) Ketone(c) 1° -amine(d) 1° - alcohal |
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Answer» Tollen’s reagent is used for detecting Aldehyde. |
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| 30. |
Dettol consists of-(a) Cresol + ethanol(b) Xylenol + ter peneol(c) Chlroxylenol + terpeneol(d) None of the above |
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Answer» Dettol consists of Chlroxylenol + terpeneol |
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| 31. |
Compare lanthanides and actinides. |
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Answer» Lanthanoids 1. Differentiating electron enters in 4f orbital 2. Binding energy of 4f orbitals are higher 3. They show less tendency to form complexes 4. Most of the lanthanoids are colourless 5. They do not form oxo cations 6. Besides +3 oxidation states lanthanoids show +2 and +4 oxidation states in few cases. Actinoids 1. Differentiating electron enters in 5f orbital 2. Binding energy of 5f orbitals are lower 3. They show greater tendency to form complexes 4. Most of the actinoids are coloured. 5. E.g : U3+ (red), U4+ (green), UO22+ (yellow) 6. They do form oxo cations such as UO22+ NpO22+ etc. 7. Besides +3 oxidation states actinoids show higher oxidation states such as +4, +5, +6 and +7 |
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| 32. |
The compound [X] is–(a) R – NH – R(b) R – CN(c) R – NC(d) R – OH |
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Answer» The compound [X] is R – NC |
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| 33. |
CO is more stable at higher temperature. Why? |
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Answer» In the Ellingham diagram, the formation of carbon monoxide is a straight line with negative slope. In this case AS is positive as 2 moles of CO gas is formed by the consumption of one mole of oxygen. Hence, CO is more stable at higher temperature. |
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| 34. |
Explain Aluminothermic process. |
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Answer» Metallic oxides such as Cr2O3 can be reduced by an aluminothermic process. In this process, the metal oxide is mixed with aluminium powder and placed in a fire clay crucible. To initiate the reduction process, an ignition mixture (usually magnesium and barium peroxide) is used. BaO2 + Mg ⟶ BaO + MgO During the above reaction a large amount of heat is evolved (temperature upto 2400°C, is generated and the reaction enthalpy is - 852 kJ mol) which facilitates the reduction of Cr2O3 by aluminium power. Cr2O3 + 2Al + Δ ⟶ 2Cr+ Al2O3 |
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| 35. |
Aniline reacts with acetaldehyde to form:(a) Carbylamines(b) Nitrobenzene(c) Imine(d) Schiff's base |
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Answer» Answer is (d) Schiff's base |
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| 36. |
Nitrogen exists as diatomic molecule and Phosphrus as P4 Why? |
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Answer» Nitrogen has a triple bond between its two atoms because of its small size and high electronegativity. Phosphorus P4 has single bond, that is why it is tetraatomic. |
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| 37. |
Explain, why the valency of inert gases is zero. |
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Answer» Inert gases have very high ionisation enthalpy because they have stable electronic configuration. Therefore they have no tendency to loss electrons. Thus the valency of inert gases are zero. |
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| 38. |
Explain standard electrode potential. |
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Answer» Standard electrode potential: The potential of an electrode. When the concentration of all the species involved in a half cell is unity is known as standard electrode potential. It is denoted by E°. E = E° when [inn+] = 1 mol litre-1 |
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| 39. |
NH3 , CO2 are readily adsorbed where as H2 , N2 are slowly adsorbed. Give reason. |
Answer»
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| 40. |
What are Lewis acids and bases? Give two example for each. |
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Answer» I. Lewis acids: (i) Lewis acid is a species that accepts an electron pair. (ii) Lewis acid is a positive ion (or) an electron deficient molecule. (iii) Example, Fe2+ , CO2 , BF3 , SiF4 etc… II. Lewis bases: (i) Lewis base is a species that donates an electron pair. (ii) Lewis base is an anion (or) neutral molecule with atleast one lone pair of electrons. (iii) Example, NH3 , F- , CH2 = CH2 CaO etc…. |
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| 41. |
Ionic solids conduct electricity in molten state but not in solid state. Explain. |
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Answer» In the molten state, ionic solids dissociate to give free ions and hence can conduct electricity. However in the solid state, as the ions are not free to move but remain held together by strong electrostatic forces of attraction, so they cannot conduct electricity in the solid state. |
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| 42. |
What do you mean by acid rain? Explain. |
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Answer» Acid rain: The moisture or rain water containing harmful acids falls and collects itself in tank, ponds, lakes etc. This is called acid rain. These pollutants due SO2, NO2 etc. dissolves in water. SO2 + H2O → H2SO4 SO3 + H2O → H2SO4 3NO2 + H2O → 2HNO3 + NO↑ |
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| 43. |
Explain two important uses of formalin. |
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Answer» Two important uses of formalin. (i) It is used to preserve biological specimens. (ii) It is used for the synthesis of bakelite. |
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| 44. |
Any transition series contains only ten elements. Why? |
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Answer» 3d and 4d transition series contains only ten elements because d orbits can contain maximum ten electrons. |
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| 45. |
1. How is diborane prepared in the laboratory?2. BCl3 is a good Lewis acid. Why? |
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Answer» 1. Diborane can be conveniently prepared in the laboratory by the oxidation of sodium borohydride with iodine. 2NaBH4 + I2 → B2H6 + 2NaI + H2 2. In BCl3 , the central boron atom contains only six electrons. Hence, it has the tendency to accept electrons and acts as a Lewis acid. |
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| 46. |
Which one is stronger acid, HF or HCl? Why? |
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Answer» HCl is stronger acid because it has big size and smaller electronegativity than HF. |
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| 47. |
Give theoretical explanation for the following statements. 1. H2S is acidic while H2O is neutral. 2. Hydrogen chloride gas dissolves in water. |
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Answer» 1. S-H bond energy is less than that of O-H bond energy. So H+ can be easily generated from H2S. 2. When HCl is treated with H2O it undergoes hydrolysis as per the following reaction and dissolves. HCl + H2O → H3O + Cl- |
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| 48. |
Why Fe is transition metal but sodium is not ? |
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Answer» Fe is a d-orbital element and show properties of transition metals like variable valency, coloured ion, complex formation etc. But sodium is s-block element. It does not show the properties of transition metal. |
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| 49. |
Give the I.U.P.A.C. name of the complex salt K 3[Fe(CN)6]. |
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Answer» K3 [Fe(CN)6] → Potassium Hexa-cyanoferrate (III) |
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| 50. |
Relationship between product 1 and 2 is :A. Positional isomerB. Functional group isomersC. Chain isomerD. Metamer |
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Answer» Correct Answer - C pH of amphiprotic salt (acidic salt) and salt of weak acid & weak base is independent of concentration. |
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