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. |
If an element can exist in several oxidation states, it is convenient to display the reduction potentials corresponding to the various half reactions in diagrammatic from, known as Latimer diagram. The Latimer diagram for chlorine in acid solutionis Cl_(4)^(-)overset(+1.20V)toClO_(3)^(-)overset(+1.60V)toClO_(2)^(-)overset(+1.60V)to ClO^(-)overset(+1.67V)toCl_(2)overset(+1.36V)toCl^(-) In basic solution is : ClO_(4)^(-)overset(+0.37V)toClO_(3)^(-)overset(+0.30V)toClO_(2)^(-)overset(+0.68)to ClO^(-)overset(+0.42V)toCl_(2)overset(+1.36)toCl^(-). The standard potentials for two nonadjacent species can also be calculated by using the concept that DeltaG^(@) is an additive property but using potential is not an assitive property and DeltaG^(@)=-nFx^(0), If a given oxidation state is a the next higher oxidation state disproportionation can occur. The reverse of relative stabilities of the oxidation state can also be understood by drawing a graph of DeltaG^(@)//F against oxidation state, known as Frost diagram, Choosing the stability of zero oxidation state arbitrery as zero. The moststable oxidation state of a apecies lies lowest in the digram Disproportionation is spontaneous if the species lies above a straight line joining its two product species. Which of the followingstatements correct ? |
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Answer» `Cl_(2)` undergoes DISPROPORTIONATION into `Cl^(-0` and `ClO^(-)` at pH = 0 and pH = 14 |
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| 2. |
If an element can exist in several oxidation states, it is convenient to display the reduction potentials corresponding to the various half reactions in diagrammatic from, known as Latimer diagram. The Latimer diagram for chlorine in acid solutionis Cl_(4)^(-)overset(+1.20V)toClO_(3)^(-)overset(+1.60V)toClO_(2)^(-)overset(+1.60V)to ClO^(-)overset(+1.67V)toCl_(2)overset(+1.36V)toCl^(-) In basic solution is : ClO_(4)^(-)overset(+0.37V)toClO_(3)^(-)overset(+0.30V)toClO_(2)^(-)overset(+0.68)to ClO^(-)overset(+0.42V)toCl_(2)overset(+1.36)toCl^(-). The standard potentials for two nonadjacent species can also be calculated by using the concept that DeltaG^(@) is an additive property but using potential is not an assitive property and DeltaG^(@)=-nFx^(0), If a given oxidation state is a the next higher oxidation state disproportionation can occur. The reverse of relative stabilities of the oxidation state can also be understood by drawing a graph of DeltaG^(@)//F against oxidation state, known as Frost diagram, Choosing the stability of zero oxidation state arbitrery as zero. The moststable oxidation state of a apecies lies lowest in the digram Disproportionation is spontaneous if the species lies above a straight line joining its two product species. For a hypothetical element, the Frost diagram is shown in figure Which of the following oxidation state is least stable ? |
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Answer» -1 |
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| 3. |
If an element can exist in several oxidation states, it is convenient to display the reduction potentials corresponding to the various half reactions in diagrammatic from, known as Latimer diagram. The Latimer diagram for chlorine in acid solutionis Cl_(4)^(-)overset(+1.20V)toClO_(3)^(-)overset(+1.60V)toClO_(2)^(-)overset(+1.60V)to ClO^(-)overset(+1.67V)toCl_(2)overset(+1.36V)toCl^(-) In basic solution is : ClO_(4)^(-)overset(+0.37V)toClO_(3)^(-)overset(+0.30V)toClO_(2)^(-)overset(+0.68)to ClO^(-)overset(+0.42V)toCl_(2)overset(+1.36)toCl^(-). The standard potentials for two nonadjacent species can also be calculated by using the concept that DeltaG^(@) is an additive property but using potential is not an assitive property and DeltaG^(@)=-nFx^(0), If a given oxidation state is a the next higher oxidation state disproportionation can occur. The reverse of relative stabilities of the oxidation state can also be understood by drawing a graph of DeltaG^(@)//F against oxidation state, known as Frost diagram, Choosing the stability of zero oxidation state arbitrery as zero. The moststable oxidation state of a apecies lies lowest in the digram Disproportionation is spontaneous if the species lies above a straight line joining its two product species. What is the potential of couple (ClO^(-))/(Cl^(-)) at pH= 14 14? |
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Answer» 1.78V |
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| 4. |
If an element can exist in several oxidation states, it is convenient to display the reduction potentials corresponding to the various half reactions in diagrammatic from, known as Latimer diagram. The Latimer diagram for chlorine in acid solutionis Cl_(4)^(-)overset(+1.20V)toClO_(3)^(-)overset(+1.60V)toClO_(2)^(-)overset(+1.60V)to ClO^(-)overset(+1.67V)toCl_(2)overset(+1.36V)toCl^(-) In basic solution is : ClO_(4)^(-)overset(+0.37V)toClO_(3)^(-)overset(+0.30V)toClO_(2)^(-)overset(+0.68)to ClO^(-)overset(+0.42V)toCl_(2)overset(+1.36)toCl^(-). The standard potentials for two nonadjacent species can also be calculated by using the concept that DeltaG^(@) is an additive property but using potential is not an assitive property and DeltaG^(@)=-nFx^(0), If a given oxidation state is a the next higher oxidation state disproportionation can occur. The reverse of relative stabilities of the oxidation state can also be understood by drawing a graph of DeltaG^(@)//F against oxidation state, known as Frost diagram, Choosing the stability of zero oxidation state arbitrery as zero. The moststable oxidation state of a apecies lies lowest in the digram Disproportionation is spontaneous if the species lies above a straight line joining its two product species. Which of the followingcouple have same value of potential at pH = 0 and pH = 14? |
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Answer» `(ClO_(4)^(-))/(ClO_(3)^(-))` |
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| 5. |
If an electron having kinetic energy 2 eV is accelerated through the potential difference of 2 volt. Then calculate the wavelength associated with the electron |
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Answer» INCREASE in `KE` due to acceleration `=qxxV=exx2v=2eV` `:.` Fimal kinetic energy, `KE_(f)=2+2=4 eV`. `:.` Associated de-Broglie WAVELENGTH, `lambda=12.27/sqrt(4)=6.15 Å` |
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| 6. |
If an atom has electronic configuration 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(3)4s^(2), it will be placed in |
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Answer» SECOND GROUP |
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| 7. |
If an atom from body-centred is removed in bcc, the packing fraction will be .... |
| Answer» ANSWER :A | |
| 8. |
If an atom crystallizes in bcc lattice with r = 4 A^@, edge length will be .......... |
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Answer» `2A^@` |
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| 9. |
If an aqueous solution of NaCl is electrolysed using platinum electrode by a currect of 5 amp, then what volume of Cl_(2) gas in litres at STP will be produced ? |
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Answer» |
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| 10. |
If an aqueous solution of glucose allowed to freeze then crystalof which will be separated out first |
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Answer» Glucose |
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| 11. |
If an acid-base reaction HA(aq)+B^(-)(aq)hArr HB(aq)+A^(-)(aq) has K_(aq)=10^(-4).how many of the following statements are true? (i) HB is stronger acid than HA (ii) HA is stronger acid than HB (iii) HA and HB have the same acidic strength (iv) B^(-) stronger base than A^(-) (v) A^(-) is stronger base than B^(-) (vi) B^(-) and HB are conjugate acid-base pair (vii) A^(-) is the conjugate base of acid HA. (viii)HA can beHSO_(4)^(-) and HB can be HCOOH. A^(-) can be F^(-) and B^(-) can be CN^(-) |
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Answer» Solution :`HA(aq)+B^(-)(aq)hArr HB(aq)+A^(-)(aq)""K_(eq)=10^(-4)` `K_(eq)` is very small .So reaction SHIFT in BACKWARD direction. `(1) HB` is more stronger acid than `HA` (2) `A^(-)` is more stronger base than `B^(-)` (3) `B^(-)` and `HB` are conjugate acid-base PAIR. |
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| 12. |
If ammonia is added to pure water the concentration of a chemical species already present will decrease.The species is : |
| Answer» ANSWER :C | |
| 13. |
If amount of radioactive substance is increased three times, the number of disintegrating atoms per unit time will: |
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Answer» be doubled |
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| 14. |
If alpha is the reaction of HI dissociation at equilibrium n the reaction, 2HI hArrH_(2)+I_(2) then starting with 2 moles of reactants and products at equlibrium is |
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Answer» `{:("Initial mole",2,0,0),("At EQ.",2(1-alpha),alpha,alpha):}` Total mole `=2(1-alpha)+alpha+alpha=2` |
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| 15. |
If alpha is the fraction of HI dissociated at equlibrium in the reaction :2H hArr H_(2)+I_(2) then starting with 2 mol of HI, the total number of moles of reactants and products at equlibrium are |
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Answer» 1 `{:("Initial MOLES",2,0,0),("At eqm.",2(1-alpha),alpha, alpha):}` |
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| 16. |
If alpha is the degree of ionization, C the concenr=tration of a weak electrolyte and K_(a) the acid ionization constant, then the correct relationship between alpha, C and K_(a) is |
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Answer» `alpha^(2) = SQRT((K_(a))/(C))` |
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| 17. |
If alpha is the degree of dissociation of Na_(2)SO_(4), the Vant Hoff's factor (i) used for calculating the molecular mass is |
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Answer» `1+alpha` `i=(Exp. C.P.)/("Normal C.P.")=1-alpha+2alpha+alpha=1+2alpha` |
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| 18. |
If alpha is the degree of dissociation of Na_(2)SO_(4) , the Van't Hoff factor (i) used for calculating molecular mass is : |
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Answer» `1+ALPHA` `alpha=(i-1)/(n-1)=(i-1)/2` `i=1+2alpha` |
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| 19. |
If alpha is the degree of dissociation of Na_2SO_4, the Vant Hoff factor (i) used for calculating the molecular mass is |
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Answer» `1+alpha` |
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| 20. |
If alpha is the degrcc of dissociation of Na_(2) SO_(4) the Vant Hoff s factor (i) uscd for calculating the molecular mass is |
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Answer» `1+ alpha ` `{:(" Mol. Beforre dissociation",1,0,0),("Mol after dissociation",1-alpha, 2 alpha, 1 alpha ):}` `i =1- alpha+ 2 alpha + alpha =1+ 2 alpha ` |
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| 21. |
If alpha is the degree of dissociation of N_(2)O_(4)inthe reaction :N_(2)O_(4)hArr 2NO_(2)then at equilibrium, the total number of moles of N_(2)O_(4)andNO_(2)present is : |
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Answer» 2 If `alpha` is the degree of dissociation `1-alpha "" 2ALPHA` Total no. of moles `=1-alpha+2alpha=1+alpha` |
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| 22. |
If all the F atoms are replaced by 'O' atom from SF_(4) without changing the covalency of 'S' atom then, which of the following property undergoes change in the process? |
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Answer» Oxidation STATE of 'S' atom
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| 23. |
If all the three interaxial angles defining the unit ceil are equal in magnitude, the crystal cannot be!ong to (I) Orthorhombic system (II) Monoclinic system (III) Hexagonal system (IV) Tetragonal system |
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Answer» II, III |
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| 24. |
If alkyl halide is optically active SN^(1) reaction leads to, |
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Answer» RACEMISATION |
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| 25. |
If all the atoms, on the shaded plane are removed then the molecular formula of the solid will be |
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Answer» `A_(5)B_(7)` |
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| 26. |
If air is taken as a binary solution, the solvent is |
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Answer» `N_2` |
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| 27. |
If air contains N_2 and O_2 in volume ratio 4:1, the average vapour density of air is : |
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Answer» 14.5 |
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| 28. |
If air is taken as a binary solution, the solved is |
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Answer» `n_(2)` |
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| 29. |
If AgNO_(3) solution is added in excess to 1 M solution of CoCl_(3)xNH_(3), one mole of AgCl is formed. What is value x |
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Answer» |
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| 30. |
If Agl crystallises in zinc blende structure with I^(-) ions at lattice points. What fraction of tetrahedral voids is occupied by Ag^(+) ions |
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Answer» 0.25 `therefore` Number of tetrahedral voids occupied by `Ag^(+)` ion =50% |
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| 31. |
IfAgCl hArr Ag^(+) + Cl^(-) K_(eq) = 10^(-10) AgBr hArr Ag6(+) + Br(-) K_(eq) = 10^(-12) Ag(NH_(3))_(2)^(+) hArr Ag6(+) + 2NH-(3) K_(eq) = 10^)(-8) (At 25^(@)C assume (RT)/(F) = 0.06) Match the following columns: |
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Answer» |
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| 32. |
If Ag_(2)O (s) is ecposed to atmosphere having pressure 1 atm and temperature 1 atm and temperature 27^(@)C. Under these conditions comment whether it will dissociate spontaneously or not. 2Ag_(2)O (s) hArr 3Ag(s)+O_(2)(g) {:("Given :",,DeltaH_(f)^(@)" (kJ/mol)",DeltaS^(@)" (J/K mol) at "27^(@)C),(,Ag(s),0,42.0),(,Ag_(2)O(s),-30,121.0),(,O_(2)(g),0,204.0):} (Air consist of 20% O_(2) by volume) Take : R=8.3 JK^(-1) mol^(-1) |
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Answer» SOLUTION :`DeltaG^(@)=DELTAH^(@)-T DeltaS^(@)` `DeltaH^(@)=DeltaH_(f)^(@)("product")-DeltaH_(f)^(@) ("reactants")` `=2xx30=60 kJ` `DeltaS^(@)=204+4(42)-2(121)=+130` `DeltaG^(@)=DeltaH^(@)-T DeltaS^(@)=60000-300xx130` `DeltaG^(@)=21000 J=-RT ln K` `log K=-(21000/(300xx8.3xx2.3))` `K_(p)=2.15xx10^(-4)` atm The dissociation of `Ag_(2)O` is nonspontaneous at `27^(@)C` |
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| 33. |
If Ag^(+)+2NH_(3)iff[Ag(NH_(3))_(2)]^(+),K_(1)=1.7xx10^(7) Ag^(+)+Cl^(-)iffAgCl,K_(2)=5.4xx10^(9) Then for AgCl+2NH_(3)iff[Ag(NH_(3))_(2)]^(+)+Cl^(-) equilibrium constant will be |
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Answer» `0.31xx10^(-2)` `AG^(+)+2NH_(3)iff[Ag(NH_(3))_(2)]^(+),K_(1)=1.7xx10^(7)` For `Ag^(+)+Cl^(-)iffAgCl,K_(2)=5.4xx10^(9)` THUS for, `AgCliffAg^(+)+Cl^(-),K._(2)=(1)/(K_(2))=(1)/(5.4xx10^(9))` Now for the reaction, `AgCl+2NH_(3)iff[Ag(NH_(3))_(2)]^(+)+Cl^(-)` `K=K_(1)xxK._(2)=1.7xx10^(7)XX(1)/(5.4xx10^(9))=0.31xx10^(-2)` |
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| 34. |
If after addition of 'V' litres of water in 1 litre solution of 2.5 xx 10^(-3) M Ba(OH)_(2), pOH of solution becomes 3 times, and if V is expressed in scietific notattion as x xx 10^(y) then calculate value of y. |
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Answer» |
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| 35. |
If adsorption occur on solid surface is limited to uni molecular layer than which of the following statement is true ? |
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Answer» Value of `(x)/(m)` remain independent of effect of less pressure of gas. |
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| 36. |
If addition of conc. H_(2)SO_(4) is made to an unknown salt, a colourless and odouriess gas is produced then which of the following can be present ? |
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Answer» `CO_(3)^(2-)` |
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| 37. |
If activation energy of reaction is given as (2500 + 3T) R then calculate the value of In k (rate constant) at 100 K. Give your answer by multiplying with10 ["Given" : In 1000 ~=7] |
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Answer» |
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| 38. |
Ifacidifiedsolution of K_(2)Cr_(2)O_(7)turmgreenon additionof a saltthree saltmay contain Fe^(2+). |
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Answer» `Cr_(2)O_(3)^(2+)//H^(oplus)` can oxidise `Fe^(2+)` in `Fe^(2+)` giving greencolouration at the and point |
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| 39. |
If activation energy of a reaction is zero, how does rate constant of the reaction change with temperature ? |
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Answer» SOLUTION :RATE CONSTANT does not CHANGE with change in TEMPERATURE. `K=AE^(-e_a//RT)=Ae^@=A` |
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| 40. |
If acetylene is passed through an electric arc in the atmosphere of nitrogen , the compound formed is |
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Answer» HCN |
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| 41. |
If acetic acid reacts with methyl alcohol containing labelled oxygen atom . Inpresence of dry HCl, the labelledoxygenatom, at thecomplete reaction will be found in |
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Answer» methyl ACETATE |
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| 42. |
If above tube is placed vertically with the open and upward then find the length of the air column. |
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Answer» `P_2=75+10+(20.4xx10)/13.6=100` cm of Hg `IMPLIES 75xx24=100xx X` |
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| 43. |
If acetyl chloride is reduced in presence of BaSO_4+ Pd, the product formed is : |
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Answer» `CH_3CHO` |
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| 44. |
If above graph is correct for 1s then |
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Answer» `PSI` is zero when`R cancel(=) 0` |
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| 45. |
If AB_(4)^(n) types species are tetrahedral, then which of the following is /are correctly match ? |
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Answer» `{:(A,B,n),(XE,O,0):}` |
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| 46. |
If a,b and c and alpha, betaand gammaare the edges and angles of a unit cell, then an orthorhombic unit cell is described as : |
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Answer» a=B`CANCEL(=)c,alpha,BETA=gamma =90^(@)` |
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| 47. |
If a_0 is the radius of first Bohr's orbit of H-atom, the de-Broglie's wavelength of an electron revolving in the 2nd Bohr's orbit will be |
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Answer» `4pia_(0)` `r_(a)=0.529xx(4)/(1)` `r_(a)=4a_(0)` `nlamda=2pir_(a)` `=pi4a_(0)=4pia_(0)`. |
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| 48. |
If a unimolecular reaction, A(g) toProducts, takes place according to the mechanism (I) A+Aoverset(k_(1))underset(k_(-1))(hArr)A^(a)+A (II) A^(a)underset(k_(2))(to)P where k_(1), k_(-1) and k_(2) are the rate constants and P, A and A^(a) stand for product molecule, normal molecule of reactant and activated molecules of reactant and activated molecules of reactant respectively. The order 'n' initial concentration a_(0) and time of half reaction t_(1//2), for a reaction are related as |
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Answer» `LN t_(1//2)=ln("constant")-(N-1)lna_(0)` |
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| 49. |
If [A_(0)] is the initial concentration and [A] is the concentration at time t then : |
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Answer» `[A] = [A]_(0) E^(k//t)` |
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| 50. |
If a unimolecular reaction, A(g) toProducts, takes place according to the mechanism (I) A+Aoverset(k_(1))underset(k_(-1))(hArr)A^(a)+A (II) A^(a)underset(k_(2))(to)P where k_(1), k_(-1) and k_(2) are the rate constants and P, A and A^(a) stand for product molecule, normal molecule of reactant and activated molecules of reactant and activated molecules of reactant respectively. For the reaction scheme, X+Yoverset(k_(f))underset(k_(b))(hArr)Z, Y+Zoverset(k)(to)T, the rate equation for the formation of T will be |
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Answer» `(d(T))/(dt)=(k_(f)K[X][Y])/(k_(B)+k[Y])` |
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