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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 the state of hybridisation of C in CO_(3)^(2-) ? |
| Answer» SOLUTION :C in `CO_(3)^(2-)` has `SP^(3)` hybridisation. | |
| 2. |
What is the Oxidation number of sulphur in Perdisulphuric acid ? |
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Answer» `+4`  The two .O. atoms of peroxy bonds have (-1) OXIDATION state. `H_(2)S_(2)O_(8)=2H+6(O)+2O` of peroxybond + 2(s) `therefore0=2(+1)+6(-2)+2(-1)+2(S)` `therefore` 2(S) = -12 `thereforeS=+6` |
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| 3. |
Which of the following does not given alkane? |
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Answer» Reaction of `CH_3I` with NA in ether |
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| 4. |
What is the covalent and van der Waals radius in Cl_(2)? |
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Answer» Solution :`r_(a) (Cl_(2))` = 99 pm but van DER Waals RADIUS = 180 pm |
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| 5. |
When alkaline earth metals dissolve ini ammonia, they form coloured solution like alkali metals. Which of the following observations regarding the reaction are correct? (i) Dilute solutions are bright blue in colour due to solvated electrons. (ii) These solutions decompose to form amides and hydrogen. (iii) From this solution the ammoniates [M(NH_(3))_(6)]^(2+) can be recovered by evaporation. |
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Answer» Only (i) and (ii) `MTO M^(2+) +2e^(-)` `2NH_(3)+2e^(-) to 2NH_(2)^(-)+H_(2)` `M^(2+)+2NH_(2)^(-) to M(NH_(2))_(2) OVERSET("evaporation")to [M(NH_(3))_(6)]^(2+)` `[M(NH_(3))_(6)]^(2+) to M(NH_(2))_(2)+4NH_(3)+H_(2)` |
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| 6. |
Which amongst the following is the strongest acid ? |
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Answer» `CHBr_(3)` |
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| 7. |
Which of the following pair is an electron rich hydride? |
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Answer» `NH_(3)`,`H_(2)O` |
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| 8. |
Which of the following reaction will be favoured at low pressure ? |
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Answer» `N_(2) + O_(2) HARR 2 NO` |
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| 9. |
When 2s orbital overlaps with 2p_(x) or 2p_(y) orbital (assuming Z-axis as the internuclear axis ), there is a partial overlap , yet they don't form any molecular orbital.Explain why. |
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Answer» SOLUTION :This is bacause 2s ORBITAL weve function has same SIGN throughout but `2p_(x) or 2p_(y)`orbital weve function has + ve sign in one lobe and -ve sign in the other lobe. The SMALL ++ overlap cancels the +- overlap which being equal in area but opposite in sign |
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| 10. |
What do you mean by ortho and para position directional groups ? Explain ortho and para position directional effect by taking examples of any group. |
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Answer» Solution :(a) Definition : If in monosubstituted benzene if second group reactat ortho and PARA POSITION with respect to first entered group (Z) then first entered group is ortho and para DIRECTING group. `-OH, -OCH_(3), -NH_(2), -CH_(3), -C_(2)H_(5), -NHCH_(3), -NHR, -NHCOCH_(3), -NHCOR` etec. are ortho and para directing group. (b) Explanation about directional proerties of -OH groups : -OH group (Hydroxyl group) is ortho and para directing, which can be explain as follows. -OH group is present in phenol. The resonance structures of phenol is as given below. 
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| 11. |
What happens when hydrogen reacts with (i)O_(2)(ii) Cl_(2) (ii) Na ? |
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Answer» Solution :(i) `2H_(2(g))+O_(2(g))to2H_(2)O_((l))` - WATER (ii) `H_(2(g))+Cl_(2(g))to2HCI_((g))` - Hydrogen Chloride (iii) `2Na_((s))+H_(2(g))toNaH_((s))`- SODIUM HYDRIDE |
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| 12. |
Which of the following alkali metals form only, the normal oxide, M_(2)O on heating in air ?(where M is the alkali metal) |
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Answer» Rb |
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| 13. |
Water loving polar molecules are called |
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Answer» `H_(2)` |
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| 14. |
Which ordering of compounds is according to the decreasing order of oxidation state of nitrogen ? |
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Answer» `HNO_(3),NO,NH_(4)CI,N_(2)` `HNO_(3):(+1)+X+2(-3),x=+5` `NO:x+(-2),x=+2` `Nh_(4)CI: X+4(+1)+(-1),X=-3` `N_(2):2x=0,x=0` Correct decreasing order of oxidation states `underset(+5)HNO_(3) underset(+2)Nounderset(0)N_(2)underset(-3)NH_(4)CI` |
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| 15. |
Which of the two structures (A) and (B) given below is more stabilised by resonance. Explain (A) CH_(3)COOH (B) CH_(3)COO^(-) |
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Answer» Solution :(B) `CH_(3)COO^(-)` is more stabilised (A) Resonance structure of `CH_(3)COOH`:  The separation of charge is in structure (II) so, it is more ENERGY containing and less stable. `THEREFORE` There is a less stabilisation of structure (A). (B) Resonance structure of `CH_(3)COO^(-)`:  Both the resonance structure of compound (B). i.e. x and y are of eqal energy and hence contribute equally towards the resonance hybrid of structure (B) is more stable than structure (A). |
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| 16. |
Which multiple bond is in ethine (C_(2) H_(2)) ? Why ? |
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Answer» SOLUTION :There is a triple bond between two CARBON. As three SHARED electron pairs between them. `H - C EQUIV C - H ` 
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| 17. |
What are the reactions involved in removing SO_2 from the atmosphere by passing it through a solution containing nitrate ions ? |
| Answer» SOLUTION :`SO_2+H_2O HARR HSO_3^(-) + H^(+) , HSO_3^(-) + H_2Cit^(-) to UNDERSET"(Complex)"(HSO_3.H_2Cit)^(2-)` | |
| 18. |
What is the decreasing order of strength of the bases OH^(-),NH_(2)^(-),HC-=C^(-) and CH_(3)CH_(2)^(-)? |
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Answer» `CH_(3)CH_(2)^(-) gt NH_(2)^(-) gt HC -=C^(-) gt OH^(-)` |
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| 19. |
What conclusion would you draw if during Lassaigne's test, a blood red colouration is obtained ? |
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Answer» Solution :The formation of BLOOD red colouration during Lassaigne's test indicates the presence of both N and During fusion, sodium thiocyanate is FORMED which gives blood red colouration with `FeCl_(3)`. `3NaCNS+FeCl_(3) RARR UNDERSET("(Blood red)")(Fe(CNS)_(3))+NaCl` |
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| 20. |
What is the self linking property of an atom known as ? |
| Answer» SOLUTION :CATENATION | |
| 21. |
When an electric discharge is passed through hydrogen gas, the hydrogen m olecu les dissociate to produce excited hydrogen atoms. These excited atom s em it electrom agnetic radiation of discrete frequencies which can be given by the general formula What points of Bohr’s model of an atom can be used to arrive at this formula ? Based on these p o in ts derive the above form ula giving description of each step and each term. |
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Answer» SOLUTION :The two im portant points of Bohr.s m odel that can be used to derive the given formula are as follows (i) Electrons revolve around the nucleus in a circular p ath of fixed radius an d energy.T hese p ath s are called orbits, stationary states or allowed energy states. (II) E nergy is e m itte d or a b so rb ed w H e n an electron m oves from higher stationary state to lower stationary state or from lower stationary state to higher stationary state respectively. The energy GAP between the two orbites is given by the equation `triangleE=E_(f)-E_(i)` where `n_(i)` and `n_(f)` stand for initial orbit and final orbit frequencyv associated with the abosrption and emission of the photon can be calculated as follows `v=3.29xx10^(15)((1)/(n_(i)^(2))-(1)/(n_(f)^(2))Hz)` `barv =(v )/(c )=(329 xx10^(15))/(3XX10^(8) ms^(-1))(1)/(n_(i)^(2))-(1)/(n_(f)^(2))` `barv =109677 (1)/(n_(i)^(2))-(1)/(n_(f)^(2))cm^(-1)` |
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| 22. |
Which of the following orders are correct? |
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Answer» `AgClgtAgF` : COVALENT character ORDER |
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| 23. |
What would be the group and period of the element with atomic number 80 ? |
| Answer» SOLUTION :The element with Z value 80 is mercury(Hg). It is present in period 6 and group II B. | |
| 24. |
Which of the following isotope of uranium is useful in producing nuclear energy ? |
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Answer» `""_(92)^(238)U` |
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| 25. |
What is the cause of Geometrical Isomerism ? |
| Answer» Solution :The RESTRICTED rotation AROUND CARBON to carbon DOUBLE bond. | |
| 26. |
Which of the following curves corresponds to the titration of a weak base with a strong acid? |
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Answer»
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| 27. |
Which set of elements shows positive electron gain enthapy? |
| Answer» Answer :d | |
| 28. |
Which among the folJowing is the strongest reducing agent? |
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Answer» Na |
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| 30. |
The standard Gibbs energy change at 300 K for the reaction 2A hArr B+ C is 2494.2 J. At a given time, the composition of the reaction mixture is [A] = (1)/(2), [B]=2 and [C]= (1)/(2). The reaction proceeds in the : [R= 8.314 "J/K/mol", e=2.718] |
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Answer» forward direction because `Q gt K_C` `RARR-0.434 = LOG K_C` `rArr K_c = "antilog" (-0.434)` `rArr K_c = 0.367` Now, `[A] = (1)/(2) , [B] =2 and [C] = (1)/(2)` Now, `Q_C = ([C] [B])/( [A]^(2) ) = (((1)/(2)) (2) )/( ((1)/(2))^(2) )= 4` As `Q_cgt K_c`, hence reaction will shift in backward direction. |
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| 31. |
Which of the following can be used for nitration of aromatic compound ? |
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Answer»
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| 33. |
Which of the following reactions give diastereomeric products? |
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Answer»
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| 34. |
What happens when potassium is treated with water? |
| Answer» Solution :Potassium reacts even more violently. The liberated HYDROGEN catches fire instantly and burns with a lilac COLOURED flame because of potassium.`2K + H_(2)O to 2KOH + H_(2)uarr + HEAT` | |
| 35. |
What is formula of calculation of Dry gas ? |
| Answer» SOLUTION :`p_("Dry GAS")=p_("TOTAL")-p_(H_(2)O)` (T CONSTANT) | |
| 36. |
What is thedifference in 2p_(x ),2p_(y),2p_(z)? |
| Answer» SOLUTION :Theirvaluesof `m_(1) ` ISDIFFERENCE+ 1,0 -1locatedin X , y ANDZ. | |
| 37. |
What designation is given to an orbital having n = 2, l = 1, (ii) n = 3, l = 0, (iii) n = 5, l = 3 (iv) n = 4, l = 2? |
| Answer» SOLUTION :(i) 2P (II) 3s (iii) 5f (iv) 4D | |
| 38. |
Which of the following arrangements shows the schematic alignment of magnetic moments of antiferromagentic substance ? |
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Answer»
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| 39. |
Which of the following reagents is used to distinguish between methanoic acid and ethanoic acid ? |
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Answer» AMM. Silver NITRATE solution |
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| 40. |
usings,p,dnotationsdescriblethe orbitalwith thefollowingquantumnumbers . ( a)n= 1, l =0( b)n = 3, l= 1( c) n=4,l=2 ( d) n=4, l=3 |
Answer» SOLUTION :
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| 41. |
Using Molecular Orbital Theory explain why the B_(2) molecule is paramagnetic ? |
| Answer» Solution :`B_(2)` molecule is paramagnetic. Due to the PRESENCE of lone PAIRS of ELECTRONS | |
| 42. |
When H_2O_2is treated with a solution of titanium dioxide in conc. H_2SO_4an orange coloured compound is formed. The oxidation number of the metal in that compound is |
| Answer» SOLUTION :The COMPOUND is `H_2TiO_4` | |
| 43. |
What type of Van der waals force exists between HCl molecules? |
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Answer» |
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| 44. |
Two volatile and miscible liquids can be separated by fractional distillation into pure components under the conditions when: |
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Answer» they have low BOILING points |
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| 45. |
The stabiliy of nuclies has been explained in terms of binding energy. Higher is binding energy, more is stabliliy to nucleus. The binding energy is written as B.E = 931.478 xx Delta m' MeVm wehre Delta m' is mass decayed in amu. If B.E.//"nucleon" lies below the belt ofstablilty, the nucleus undergoes alpha- emission in order to lower down the energy level of nucleus but its n//p ratio increases. To lower down the energy level of nucleus but is n//p ratio increases.To lower downlevel of nucleus loses beta- particles and if stability is not gained, gamma- emission is noticed. A radioactive element on losing on alpha- particles shows a loss in its mass number by 4 units and atomic number by 2 units whereas beta- emission leads to a gain in at.no by one units and mass no. remains same. Loss in mass during the change. |
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Answer» `3.07xx10^(-26)g` `:.` Mass decayed `= (17.25)/(931.5) = 0.0185` amu `= 0.0185xx1.66xx10^(-24)g` `= 3.07xx10^(-24)g` |
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| 46. |
Which of the following oxides is most acidic in nature? |
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Answer» CaO BeO having least basic strength and hence, it is the most ACIDIC. So BeO is amphoteric in nature. |
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| 47. |
Which is the IUPAC name of HCOOCH_(3) ? |
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Answer» METHYL ethanoate |
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| 48. |
What will be the resultantpH when 200 ml of an aqueous solution of HCl (pH=2.0) is mixed with 300 ml of an aqueous solution of NaOH(pH=12.0) ? |
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Answer» |
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| 49. |
What are primary and secondary pollutants of the air ? |
| Answer» Solution :Primary pollutants are those which after their formation remain as such, e.g, NO. Secondary pollutants are those which are FORMED as a RESULT of reaction between primary pollutants, i.e., PAN (PEROXYACYL nitrates). | |
| 50. |
What happens when Borax is heated strongly |
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Answer» Solution :When heated, BORAX undergoes various transitions. It FIRST loses water molecules and swells. Then, it turns into a transparent liquid, solidifying to FORM a glass-like MATERIAL called borax bead. `underset"Borax"(Na_2B_4O_7). 10H_2O oversetDeltato Na_2B_4O_7 + 10H_2O` `Na_2B_4O_7oversetDeltatoubrace(underset"Sodium METABORATE"(2NaBO_2)+underset"Boric anhydride"(B_2O_3))_("Transparent bead")` |
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