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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.
| 2. |
Which of the following has pK_(w)=13.36 at 50^(@)C, the pH of pure water will be |
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Answer» `H_(2)O` `2H_(2)O hArr H_(3)O^(+)+OH^(-)` `2NH_(3) hArr NH_(4)^(+)+NH_(2)^(-)` `2HF hArr H_(2)F^(+)+F^(-)` |
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| 3. |
Write structures of various carbocatins that can be obtained from 2-methylbutane. Arrange these carbocation in order of increasing stability |
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Answer» Solution :2-methyl butane has four different sets of equivalent H atoms marked as 1, 2, 3 and 4. `overset(1)(C )H_(3)- underset(underset(CH_(3))(|))overset(2)(C )H- overset(3)(C )H_(2) - overset(4)(C )H_(3)` Removal of ONE hydrogen from any of these equivalent sets of hydrogen gives four different CARBONCATIONS (a), (b), (c ), (d) as shown below: (a) Minimum STABLE  (b) Medium stable (-ve `CH_(3)` has strong +1 effect)  (c ) Maximum stable +I effect of `CH_(3)CH_(2)` is medium  (d) Stability of (d) `gt` Stability of (a)  Now stability of carbocations decreases in the order: `3^(@) gt 2^(@) gt 1^(@)` `therefore` (b) `gt` (c ) `gt` [(a) and (d)] but stability of (d) is more than (a) because +I containing alkyl group `(CH_(3))_(2)CH CH_(2)`- is more strong is (d)  `therefore` Decreasing order of stability : `(b) gt (c ) gt (d) gt (a)` and lecresing order of stability : `(a) lt (b) lt (c ) lt (b) rarr` stability increase `rarr` In ADDITION based on no of hyperconjugation `alpha` stability so same stability order is obtained |
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| 5. |
Why alkaline earth metals are harder than alkali metals? |
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Answer» Solution :(i) The STRENGTH of metallic bond in ALKALINE earth metals is higher than alkali metals due to the presence of 2 electrons in its OUTERMOST shell as compared to alkali metals, which have only 1 electron in Valence shell Therefore, alkaline earth metals are harder than alkali metals (Ii) The alkaline earth metals have greater nuclear charge and more valence electrons, thus metallic bonding is more effective. Due to this they are harder than alkali metals. |
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| 6. |
What are the main constituents of light oil fraction of coal tar? |
| Answer» SOLUTION :BENZENE, TOLUENE and XYLENE | |
| 7. |
Which of the following is not benzenoid ? |
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Answer»
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| 8. |
Write the general properties of alkali metals. |
| Answer» Solution :The general PROPERTIES of alkali metals are: (a) They are most electropositve metals. (B) They FORM monovalent cations. (c ) These metals are SOFT, light and can be cut with knife. (Except lithium). (d) They are highly REACTIVE metals and are stored under kerosene to prevent from air and moisture. | |
| 9. |
Which of the following compounds contain all the carbon atoms in the same hybridisation state ? |
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Answer» `H-C -= C-C-=C-H` (c) `overset(sp^(2))(C)H_(2)=overset(sp)(C)=overset(sp^(2))(C)H_(2)`(d) `overset(sp^(2))(C)H_(2) =overset(sp^(2))(C)H-overset(sp^(2))(C)H = overset(sp^(2))(C)H_(2)` |
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| 10. |
Which of the following applies corretly to toluene |
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Answer» When heated with limited amount of CHLORINE as Benzyl chloride is formed |
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| 11. |
Wavelength of the wave associated with a moving electron |
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Answer» DECREASES with INCREASE in SPEED of electron |
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| 12. |
Which are the colour of [CoCl_4]^(2-) and [Co(H_2O)_6]^(2+) complex ion ? |
| Answer» SOLUTION :BLUE and PINK RESPECTIVELY | |
| 13. |
Write the increasing order of bond energies of H_2F_2 and HF molecules. |
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Answer» Solution :Bond in `F_(2)` is weak due to IONE pair repulsions. Bond in `H_(2)` is strong because bond length is least. Bond in HF is strongest single bond because of HIGH polarity. INCREASING ORDER of energies `F_(2)ltH_(2)ltHF` |
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| 15. |
x underset("boil")overset("dil".H_2SO_4)rarrYunderset(Delta)overset("Zn dust")rarrQwhere if 1 made Y on ozonolysis yields three moles of ethane - 1 , 2-dial, X and Q respectively are |
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Answer» Napthalen : PHENOL |
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| 16. |
What are Y and Z in the following sequence? CH_(2)=CHBroverset(NaNH_(2))rarrYunderset(H_(2)O,333K)overset(Hg^(2+)//H^(+))rarrZ |
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Answer» `{:("X","Y"),("ethane","ethanol"):}` |
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| 17. |
Which of the following statement(s) "is"//"are" correct ? |
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Answer» `H_(2)SO_(4) " and" H_(3)PO_(3)` both are DIBASIC |
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| 18. |
What will be the molarity of the solution containing 18.25 g of HCl gas in 500 g of water ? |
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Answer» 0.1 m Thus, Molality `=("Moles of solute")/("MASS of solvent (in kg)")` ......(i) GIVEN that, Mass of solvent `(H_(2)O)=500 g = 0.5 kg` Weight of HCl `= 18.25g` Molecular weight of HCl `= 36.5 g` Moles of HCl `= (18.25)/(35.6)=0.5` `m= (0.5)/(0.5)=1 m` ...( `:. (i)` ) |
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| 19. |
Which of the hydrogen or deuterium undergoes reactions more rapidly and why ? |
| Answer» SOLUTION :Hydrogen UNDERGOES reaction more rapidly than deuterium. This is because of mass DIFFERENCES. For EXAMPLE, reaction between hydrogen and chlorine is about 14 TIMES faster than between deuterium and chlorine. | |
| 20. |
Which one of the following is the most stable alkene? |
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Answer» Isobutylene |
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| 21. |
What are the enthalpies of sigma-bond and pi-bonds in alkene? |
| Answer» SOLUTION :`297 KJ MOL^(-1)` and `284 kJ mol^(-1)` RESPECTIVELY. | |
| 22. |
Which is responsible mainly for depletion of ozone layer ? |
| Answer» Answer :A | |
| 23. |
Write the relationship between K_(sp) and S of an AB_(2) type of salt. |
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Answer» Solution :Consider an electrolyte `AB_(2)`, whose solubility is S mol `dm^(-3)`. In a saturated solution, `AB_(2(s))hArrA^(2+)+2B^(-)` `THEREFORE[A^(2+)]=S" mol "dm^(-3)and(B^(-))=2S" mol "dm^(-3)` `K_(sp)=[A^(2+)][B^(-)]^(2)=S:(2S)^(2)=4S^(3)` `thereforeK_(sp)=4S^(3)`. |
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| 24. |
What are the health effects of particulate pollutants? |
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Answer» Solution :(i) Dust, mist, fumes etc. are air borne particles which are dangerous for HUMAN health. Particulate pollutants bigger than 5 microns are likely to settle in the nasal PASSAGE whereas particles of about 10 microns enter the lungs easily and causes scaring or fibrosis of lung lining. They irritate the lungs and causes CANCER and asthma. This disease is called pneumoconiosis. Coal miners may suffer from black lung disease. Textile workers may suffer from white lung disease. (ii) Lead particulates affect children.s brain, INTERFERES with maturation of RBC.s and even causes cancer. (iii) Particulates in the atmosphere reduces the visibility by scattering and absorption of sunlight. It is dangerous for aircraft and motor VEHICLES. (iv) Particulates provide nuclei for cloud formation and increases fog and rain. , (v) Particulates deposit on plant leaves and hinder the intake of `CO_2` from the air and affect photosynthesis. |
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| 25. |
Which would produce chiral molecule after treatment with Lindlar catalyst? |
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Answer»
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| 26. |
Which one is correct order of dipole moment ? |
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Answer» `CH_(4) lt NF_(3) lt NH_(3) lt H_(2) O ` In `H_(2) O` molecule difference of ELECTRONEGATIVITY L0) is more. So dipole moment is more. But `CH_(4)` is symmetrical so dipole moment is zero. |
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| 27. |
Which of the following is the correct order of size of the given species : |
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Answer» `I gt I^(-)gt I^(+)` CATION is being formed after the losing of electron from its OUTER shell. Hence, cation has smaller SIZE then the anion compared to the neutral atom. Thus `I^(-) gt I gt I^(+)` |
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| 28. |
The vapour of which liq present at upper and lower side of distillation coloum? |
| Answer» SOLUTION :At INITIAL the proportion of LIQUID with right boiling point is more but after that the PREPARATION of LOW boiling point vapour is more. | |
| 29. |
Which of the following acids forms three series of salts ? |
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Answer» `H_(3)PO_(2)` |
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| 30. |
Which type of reaction can be performed on reaction of (CH_(3))_(3)CH with KMnO_(4) ? Why ? |
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Answer» Solution :`UNDERSET("2-Methyl propane")((CH_(3))_(3)CH)OVERSET(KMnO_(4))RARR underset("2-Methyl propane-2-ol")((CH_(3))_(3)C-OH)` This is a kind of oxidation of alkane. `H_(3)C -underset(" "H)underset(" "|)overset(" "CH_(3))overset(" "|)(""^(3^(@)C))-CH_(3) overset(KMnO_(4))rarr H_(3)C-underset(" "OH)underset(" "|)overset(" "CH_(3))overset(" "|)(""^(3^(@)C))-CH_(3)` In this oxidation C of `CH_(3)` is -1 and in C-OH the oxidation NUMBER of carbon +1. Oxidation state of carbon changes from -1 to +1, means increases in oxidation state, so it is oxidation. |
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| 31. |
Which is the suitable ·method for detection of Nitrogen present in food and fertilizers? |
| Answer» Solution :Kjeldahl .s METHOD is the suitable for detection of nitrogen pres,ENT in FOOD and fertilizers. | |
| 32. |
Which of the following statements are true for H_(3)BO_(3) ? |
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Answer» It is mainly monobasic acid and a Lewis acid `H_3 BO_3` has layered structure with `BO_3` units are joined by hydrogen bonds `Na_(2) B_(4)O_(7) + H_(2)SO_(4) + 5H_(2)O rarr Na_(2) SO_(4) + 4H_(3) BO_3` |
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| 33. |
Which of the following have a diagonal relationship ? |
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Answer» Li `to` MG |
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| 34. |
(vi) P+5HNO_(3) to H_(3)PO_(3)+5NO_(2)+2H_(2)O |
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Answer» Solution :All atoms are balanced Balanced EQUATION is `P+5HNO_(3) to H_(3)PO_(4)+4NO_(2)+H_(2)O` |
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| 35. |
Which molecule/ion out or the following does not contain unpaired electrons ? |
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Answer» `N_(2)^(+` The ELECTRONIC CONFIGURATION of the given `N_(2)^(+) = sigma 1s^(2), sigma^(**) 1s^(2), sigma 2s^(2), sigma^(**) 2s^(2) , pi 2p_(x)^(2)= pi p_(y)^(2)sigma 2p_(Z)^(1)` It has ONE unpaired electron. `O_(2) = sigma 1s^(2), sigma^(**) 1s^(2) , sigma 2s^(2), sigma 2p_(z)^(2), pi 2p_(x)^(2) = pi 2p_(y)^(2) pi* 2p_(x)^(1), = pi** 2p_(y)^(1)` `O_(2)` has two unpaired ELECTRONS. `O_(2)^(2-) = sigma 1s^(2), sigma^(**)1s^(2), sigma 2s^(2), sigma^(**) 2s^(2), sigma 2p_(z)^(2), pi 2p_(x)^(2) = pi 2P_(y)^(2) pi ** 2p_(x)^(1) = pi ** 2p_(y)^(1)` So, `O_(2)^(2-)` has no unpaired electrons. `B_(2) = sigma 1s^(2), sigma^(**) 1s^(2), sigma 2s^(2), sigma^(**) 2s^(2) pi 2p_(x)^(1) = pi 2p_(y)^(1)` So`B_(2)` has two unpaired electrons. |
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| 36. |
Which of the following is pure compound? |
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Answer» Copper |
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| 37. |
What is screening effect? |
| Answer» Solution :Screening effect: The REPULSIVE FORCE between inner shell electrons and the valence electrons leads to a DECREASE in the electrostatic attractive forces ACTING on the valence electrons by the nucleus. Thus the inner shell electrons act as a shield between the nucleus and the valence electrons. This effect is called SHIELDING effect (or) screening effect. | |
| 38. |
What is common ion effect? Give an example. |
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Answer» Solution :Suppression in the degree of DISSOCIATION of a WEAK electrolyte bythe addition of a COMMON ion is called common ion EFFECT. Example : `CH_(3)COOHandCH_(3)COONa`. |
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| 39. |
Which of the following is a Lanthanoid |
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Answer» Ta |
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| 40. |
What will be the change in enthalpy (Delta H) for endothermic reaction ? |
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Answer» Zero `therefore Delta H = Delta H_("(product)") - Delta H_(("reactant"))` `=+ve` 
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| 41. |
The solubility of AgCl in water at 25^(@) C is found to be 1.06xx10^(-5) moles per litre. Calculate the solubility product of AgCl at this temperature. |
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Answer» Solution :AgCl IONIZES completely in the solution as : `Agcl RARR Ag^(+) + Cl^(-)` i.e., 1 mole of AgCl in the solution gives 1 moles 1 mole of `Ag^(+)`IONS and 1 mole of `Cl^(-)` ions. Now, as the solubility of `AgCl = 1.6 xx 10^(-5)` moles PER litre `:. [Ag^(+)] = 1.06xx10^(-5)` moles/litre and `[Cl^(-)] = 1.06 xx 10^(-5)` moles/litre `:. K_(sp) ` for ` AgCl = [Ag^(+)][Cl^(-)]=1.06xx10^(-5)xx1.06xx10^(_5)=1.1xx10^(-10)` |
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| 42. |
W, X & Y are number of stereoisomers for the following compounds A) 1,2-dichloro cyclopropane= W B) 1, 3-dimethyl cyclobutane = X C) 2- bromo 3-chloro butane = Y Hance W+X+Y=__________ |
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Answer» |
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| 43. |
Use the molecular orbital energy level diagram to show that N_(2) would br expected to have a triple bond, F_(2) a single bond Ne_(2) no bond. |
| Answer» SOLUTION :For ANSWER, CONSULT SECTION 4.32. | |
| 44. |
Write the compounds formula and IUPAC names of the following compounds known by their common names : (i) Neopentane (ii) Vinyl chloride (iii) Glycerol (iv) Tert-amyl alcohol. |
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Answer» Solution :(i) `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-CH_(3)` (2, 2-Dimethylpropane) (ii) `CH_(2)=CH-Cl` (chloroethene) (iii) `underset(OH)underset(|)(C)H_(2)-underset(OH)underset(|)(C)H-underset(OH)underset(|)(C)H_(2)` (PROPANE -1, 2, 3-triol) (iv) `CH_(3)-underset(OH)underset(|)overset(CH_(3))overset(|)(C) -CH_(2)-CH_(3)` (2-Methylbutan-2-ol) |
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| 45. |
Which reaction is redox reaction ? |
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Answer» `CaCO_(3)toCaO+CO_(2)` There is no change in OXIDATION NUMBER. |
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| 46. |
The species which contains unpaired electrons is |
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Answer» Oxide ION |
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| 48. |
Which of the following is not a process of preparation of hydrogen peroxide ? |
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Answer» Auto - oxidation of 2 - ethylanthraquinol. |
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| 49. |
The Uncertainty principle isimportantfor |
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Answer» moving`alpha`particle |
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