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 one strand of DNA has the sequence 5' -G-G-A-C-T-A-C-T-3', what is the sequence of bases in the complementary strand ? |
| Answer» SOLUTION :3.-C-C-T-G-A-T-G-A-5. | |
| 2. |
If one mole of monoatomic ideal gas expanded from 2 atm to 0.5 atm at 27°C, then the entropy change will be |
| Answer» Answer :1 | |
| 3. |
If one mole of an ideal gas (C_(p.m) = (5)/(2)R) is expanded isothermally at 300 K until it's volume is tripled , then change in entropy of gas is: |
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Answer» zero |
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| 4. |
If one mole of ammonia and one mole of hydrogen chloride are mixed in a closed container to form ammonium chloride gas , then |
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Answer» `DeltaHltDeltaU` `DELTAN=` no . Ofmoles of product - no of moles of REACTANT `=1-2` `Deltan=1` Now , `DeltaH=DeltaE+DeltanRT` `DeltaH=DeltaE-RTorDeltaE=DeltaH+RT` `thereforeDeltaEgtDeltaH(DeltaE=DeltaU)`=change in internal energy. |
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| 5. |
If one mole of AgCZ is dopped with 10^(-5) mole of CaCl_(2) then number of Ag^(+) ions lost from the lattice |
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Answer» `10^(-5)` |
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| 6. |
If one mole of AgCl is dopped with 10^(-5)mole of AICI_3, the number of cation vacancies created are |
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Answer» `10^(-5)` |
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| 7. |
If onemole monoatmic ideal gas was taken through process AB as shown is figure , then select correcgtoption(s). Given: In 1.5 = 0.4 |
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Answer» `W_(AB)= - 1496.52 J` `10 = mm xx 300 + C` `15 = mxx 600+ C` `5 = 300 m` `m = (1)/(60), "" c= 5` `V=(1)/(60) T + 5""w = - int PDeltaV` `P = 60 R - (300R)/(V)` ` w = -.^(15)int_(10) (60R-(300R)/(V))DV =- 1496.52J` (b)`DELTAU= q + w or q= DeltaU-w` `DeltaU= C_(V) DeltaT =374 .13` `q = 374.13 + 1496.525 = 5237. 82 J` (c)`Deltah = (5)/(2) xx Rxx 300 ` (d) `DeltaS = + ve` |
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| 8. |
If one million atoms of silver weight 1.79xx10^(-16)gm the gram atomic mass of silver is: |
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Answer» 107 g/mol |
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| 9. |
If one litre of air is passed repeatedly over heated copper and magnesium till no further reduction in volume takes place, the volume finally obtained is |
| Answer» Answer :C | |
| 10. |
If one first order reaction is completed by 50% in 1.26xx10^(14) second then how much time will be taken by this reaction to complete 100%? |
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Answer» `1.26xx10^(15)` SECOND |
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| 11. |
If one end of a piece of a metal is heated the other end becomes hot after some time. This is due to |
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Answer» ENERGISED ELECTRONS MOVING to the other part of the metal |
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| 12. |
If one end of a piece of a metal is heated, the other end becomes hot after some time. This is due to |
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Answer» ENERGISED electrons MOVING to the other part of the metal |
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| 13. |
If one cell has standard electrode potential of 0.0295V and n=2 then calculate its equilibrium constant at 298K temperature |
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Answer» |
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| 14. |
Ifon performing theexperiment, 2 . 28 g of (NH_(4))_(2) PbCl_(6) was produced, calculatethe percentage yield of (NH_(4))_(2) Pb Cl_(6) |
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Answer» Solution :`% "yield " = ("amount produced experimentally")/("amountfor 100% yield") XX 100` `= (2 . 28)/( 4 . 56) xx 100 = 50%` |
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| 15. |
If one atom of hydrogen weighs 1.65 xx 10^(-24)g, then mass of one atom of carbon weighs |
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Answer» `1.98 xx 10^(-23) g ` |
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| 16. |
If OH-group in lactic acidis replaced by hydrogen atom, which will happened ? |
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Answer» OPTICAL ACTIVITY is retained |
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| 17. |
If O_(2) gas in bubbled through water at 293 K, how many millimoles of O_(2) gas would dissove in 1 littre of water ? Assume that O_(2) exerts a partial pressure of 0.987 bar and k_(H) for O_(2)=34.86 k bar. |
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Answer» `x_(O_(2))=rho_(O_(2))/k_(H)=((0.98"bar"))/((43860"bar"))=2.83xx10^(-5)` Step II. Calculation os milli-MOLES of `O_(2)` If N moles os `O_(2)` are present in 1 L of water (or 1000 g of water) `X_(N_(2))=n/(n+55.5)=n/(55.5)` `n=X_(N_(2))xx55.5=2.83xx10^(-5)xx55.5` `=157.06xx10^(-5)mol=157.06xx10^(-2)`milli-moles =1.57 milli-moles |
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| 18. |
If observed molar mass of a solute is more than calculated molar mass, then the solute undergoes .............. in the solvent. |
| Answer» SOLUTION :ASSOCIATION | |
| 19. |
If [OH^-] is 1 xx 10^-8 ion/litre.Is pH is: |
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Answer» 6 |
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| 20. |
If N_(x) is the number of bonding orbitals of an atom and N_y is the number of antibonding orbitals, then the molecule/atom will be stable if |
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Answer» `N_x ltN_y` |
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| 21. |
If n_(t) number of radioatoms are present at time t, the following expression will be a constant |
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Answer» `n_(t)//t` `rArr (d)/(dt) (ln, n_(t)) = - lamda`, a CONSTANT |
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| 22. |
If n_t number of radiatoms are present at time t, the following expression will be a constant. |
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Answer» `n_t//t` `implies d/(dt) (ln n_t) = -lambda`, a constant. |
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| 23. |
If no catalyst (H^(+)) is present in acid hydrolysis of ester (in above question) then constant K is : |
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Answer» `(2.303)/(t)"LOG"(V_(0))/(V_(t)-V_(oo))` |
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| 24. |
If non ideal solution is prepared by mixing 30 mL CHCl_(3) and 50 mL Acetone, then volume of solution is …….. |
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Answer» `GT` 80 ML Means,`DELTA V_(mix)-ve, Delta H_(mix)=-ve` So, total volume `= lt` 80 mL. |
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| 25. |
If NH_4OH is added to the (PtCl_2)^(2-) ion, the complexformed represents: |
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Answer» ZERO dipole |
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| 26. |
If N_(B) is the number of bonding electron and N_(A) is the number of antibonding electrons of a molecules. Then choose the incorrect statement(s) for the relationship , N_(B)gtN_(A)" |
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Answer» Molecule may be STABLE or unstable Molecule may or not be paramagnetic molecule will exist |
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| 27. |
If NaOH is added to an aqueous solution of zinc ions, a white precipitate appears ad on adding excess NaOH, the precipitate dissolves. In this solution zinc exists in the |
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Answer» Cationic part `Zn(OH)_(2)+2NaOHtoNa_(2)ZnO_(2)+2H_(2)O`. |
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| 28. |
If NaOH is added to an aqueous solution of zinc ions a white precipitate appears and on adding excess of NaOH, the precipitate dissolves. In this solution, zinc exists in the |
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Answer» CATIONIC part `Zn(OH)_(2) +2NaOH to Na_(2)ZnO_(2)+2H_(2)O` |
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| 29. |
If NaCl is doped with 10^(4) mol % of SrCl_(2) the concentration of cation vacancies will be (N_(A) = 6.02 xx 10^(23) mol^(-1)) |
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Answer» `6.02 xx10^(16) MOL^(-1)` |
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| 30. |
If NaCl is doped with 10^(-4) mol % of SrCl_(2) , the concentration of cation vacancies will be ( N_(A) = 6.022 xx 10^(23) mol^(-1)) |
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Answer» `6.02 xx 10^(18) MOL^(-1)` No. of moles of cationic vacancies ` = ( 10^(-4))/( 10^(2)) = 10^(-6)` mol No. of cation vacancies ` = 10^(-6) xx 6.02 xx 10^(23) = 6.02 xx 10^(17)` |
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| 31. |
If NaCl is doped with 10^(-3) mole percent SrCl_(2), what will be the concentration of cation vacancies ? (N_(A) = 6.02 xx 10^(23) mol^(-1)) |
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Answer» Solution :Every `Sr^(2+)` ion causes ONE cation vacancy (because two `Na^(+)` ions are REPLACED by one `Sr^(2+)`) Therefore, introduction of `10^(-3)` moles of `SrCl_(2)` per 100 moles of NaCl would introduce `10^(-3)` mole cation VACANCIES in 100 moles of NaCl. No. of vacancies per mole of NaCl `= (10^(-3))/(10000) xx 6.02 xx 10^(23) = 6.02 xx 10^(18)` vacancies. |
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| 32. |
If NaCl is doped with 10^(-3) mol % SrCl_2, what is the concentration of cation vacancies? |
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Answer» Solution :Doping of NaCl with `10^(-3) mol % SrCl_2`, means that 100 moles of NaCl are doped with `10^(-3)` mol of `SrCl_2`. `:.` 1 mole of NaCl is doped with `SrCl_2 =(10^(-3))/(100) = 10^(-5)` mol As each `SR^(2+)` ION introduces one cation vacancy, THEREFORE concentration of cation vacancies = `10^(-5) mol//mol` of NaCl = `10^(-5) xx 6.02 xx 10^(23)` cation vacancies `mol^(-1)` = `6.02 xx 10^(18)` cation vacancies `mol^(-1)` |
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| 33. |
If NaCl is doped with 10^(-3) mol % of SrCl_(2) what is the concentration of cation vacancy? |
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Answer» Solution :ONE cation of `SR^(2+)` would create one cation vacancy in NaCl. `:.`Concentration of cation vacancy on being doped with `10^(-3)` mol% `SrCl_(2)` `= 10 ^(-3) mol%` `=(10 ^(-3))/(100) "mol"` `=(10 ^(-3))/(100) XX 6.02 xx 10^(23)` cation vacancies PER mole `= 6.02 xx10^(18)`cation vacancies per mole. |
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| 34. |
If NaCl is doped with 10^(-3) mol % of SrCl_2, what is the concentration of cation vacancies ? |
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Answer» SOLUTION :Let moles of NaCl in the crystal = 100 Moles of `SrCl_2` doped = `10^(-3)` `therefore` No. of `NA^(+)` ions replaced by each `SR^(2+)` ions = 1 No. of CATIONIC vacancies formed by `Sr^(2+)` ions = 1 `therefore` Number of cationic vacancies = `10^(-3)` formed by `10^(-3)` mol `SrCl_2` `therefore` Vacancy per mole of `NaCl =(10^(-3))/(100) = 10^(-5)` `therefore` Number of vacancies per mole of NaCl ` = 6.022 xx 10^23 X 10^(-5)` ` = 6.022 xx 10^18`. |
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| 35. |
If NaCl is doped with 10^(-3) mol % of SrCl_(2), what is the concentration of cation vacancies ? |
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Answer» Solution :Let us take one MOLE of `NaCl`. For every `Sr^(2+)` ion INTRODUCED, one `Na^(+)` ion will be removed and one vacancy will be created. Amount of `SrCl_(2)=(10^(-3))/(100)" moles"` `=10^(-5)" moles "=10^(-5)xx6.02xx10^(23)" molecules "=6.02xx10^(18)" molecules"` As each `Sr^(2+)` ion intrduced creates one cation vacancy, CONCENTRATION of cation vacancies `=6.02xx10^(18)` PER mole. |
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| 36. |
If NaCl is doped with 10^(-2) mol % SrCl_2, what is the concentration of cation vacancies? |
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Answer» `:.` 1 mole of NaCl is doped with `SrCl_2=(10^(-2))/(100)= 10^(-4)` MOL As each `Sr^(2+)` ion introduces one cation vacancy, therefore, concentration of cation vacancies = `10^(-4) mol//mol` of NaCl = `10^(-4) xx 6.02 xx 10^(23)` cation vacancies `mol^(-1) = 6.02 xx 10^(19)` cation vacancies `mol^(-1)`. |
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| 37. |
If NaCl crystals are doped with 2 xx 10^(-3) mol per cent of SrCl_(2), calculate the cation vacancies per mole. |
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Answer» Solution :Doping of `NaCl` with `2xx10^(-3)` mol per cent of `SrCl_(2)` means 100 MOLES of `NaCl` are dropped with `2xx10^(-3)` moles of `SrCl_(2)` or 1 mole of `NaCl` is doped with `=2xx10^(-5)` mole of `SrCl_(2)`. Each `Sr^(2+)` will occupy the place of `Na^(+)` and displace one `Na^(+)` from crystal lattice to create cation vacancies. Cation vacancies = Number of `Sr^(2+)` ion added `=2xx10^(-5)mol=2xx10^(-5)xx6.023xx10^(23)=12.046xx10^(18)=1.2046xx10^(19)mol^(-1)`. |
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| 38. |
If NaCl is doped with 10^(-2) mol percentage of strontium chloride, what is the concentration of cation vacancy ? |
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Answer» Solution :We KNOW that two `Na^(+)`ions are replaced by each of the `Sr^(2+)` ions while `SrCl_(2)` is doped with NaCl. But in this case, only one lattice POINT is occupied by each of the `Sr^(2+)` ions and PRODUCE one cation vacancy. Here `10^(-2)` mole of `SrCI_(2)` is doped with 100 moles of NaCl. Thus, cation vacancies produced by NaCl = `10^(-2)` mol. Since, 100 moles of NaCl produces cation vacancies after doping = `10^(-2)` mol. Therefore, 1 mole of NaCl will produce cation vacancies after doping `=(10^(-2))/(100)=10^(-4)"mol"` `therefore"Total cationic vacanices,"` `=10^(-4)xx"Avogadro.s NUMBER"` `=10^(-4)xx6.023xx10^(23)` `=6.023xx10^(19)" vacancies"` |
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| 39. |
If Na_2SO_3 is left open in air, we get: |
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Answer» `Na_2S` |
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| 40. |
If N_A is Avogadro's number, then the number of hydrogen atoms in one g-equivalent of hydrogen is : |
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Answer» `N_A` |
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| 41. |
If Na^(+) ion and S^(2-) ion is larger than Cl^(-) ion, which of the following will b least soluble in water |
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Answer» `MgS` |
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| 42. |
If n_A and n_Brepresent the number of moles of components A and B, the mole fraction of A(x_A) is given by |
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Answer» `n_A//n_B` |
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| 43. |
If n=6, the correct sequence for filling of electrons will be: |
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Answer» `NSTO(N-2)F to(n-1)d tonp` `6s t o4f to 5d to 6P` |
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| 44. |
If N_(2) gas is bubbled through water at 293 K, how many millimoles of N_(2) gas would dissolve in 1 litre of water ? Assume that N_(2) exerts a partial pressure of 0.987 bar. Given that Henry's law constant for N_(2) at 293 K is 76.48 k bar. |
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Answer» Solution :The solubility of gas is related to the mole fraction in aqueous solution. The mole fraction of the gas in the solution is calculated by applying Henry.s law. Thus : x (Nitrogen) `= ("p (nitrogen)")/(K_(H))` `=(0.987" bar")/(76480" bar")=1.29xx10^(-5)` As 1 LITRE of water contains 55.5 MOL of it, therefore if n represents number of MOLES of `N_(2)` in solution, x(Nitrogen) `= ("n mol")/(n mol +55.5 mol)` `= (n)/(55.5)=1.29xx10^(-5)` (n in denominator is neglected as it is `LT lt 55.5`) Thus, `n = 1.29xx10^(-5)xx55.5 mol = 7.16xx10^(-4)` mol `= (7.16xx10^(-4)mol xx 1000 m mol)/(1 mol)` = 0.716 m mol |
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| 45. |
If N_(2) gas is bubbled through water at 293 K, how many of millimoles of N_(2) gas would dissolve in 1 litre of water 7 Assume that N_(1) exerls a partial pressure of 0.987 bar. Given that Henry's law constant for N_(2) at 293 K is 76.48 K bar. |
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Answer» Solution :ACCORDING to Henry.s LAW x(Nitrogen ) = `(p("Nitrogen"))/(K_(H))` = `(0.987)/(74,480("bar"))` = `1.29 xx 10^(-5)` As 1 litre of water contains 55.5 mole of it, therefore if n represents number of moles of `N_(2)` in solution. x (Nitrogen ) = `(n"mole")/("n mole + 55.5 mol")` = `(n)/(55.5) = 1.29 xx 10^(-5) = 1.29 xx 10^(-5)` (n in denominator is neglecti!d as it is `lt lt `55.5) So, n= 1.29` xx 10^(-5) xx 55.5 `mol = `7.16 xx 10^(-4)` mol `= (7.16 xx 10^(-4)"mol" xx 1000 "mol")/(1 "mol")` = 0.716 m/mol |
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| 46. |
If N_2 gas is bubbled through water at 293 K , how many millimoles of N_2 gas would dissolve in 1 litre of water? Assume that N_2 exerts a partial pressure of 0.987 bar. Given that Henry’s law constant for N_2 at 293 K is 76.48 k bar. |
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Answer» |
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| 47. |
If N_(2) gas is bubbled through water at 293 K, how many millimoles of N_(2) gas would dissolve in 1 litre of water ? Assume that N_(2) exerts a partial pressure of 0.987 bar. Given that Henry's law constant for N_(2) at 298 K is 76.48 kbar. |
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Answer» <P> Solution :`"According to Henry's law, "p_(N_(2))=K_(H)xxx_(N_(2)), thereforex_(N_(2))=(p_(N_(2)))/(K_(H))=("0.987 bar")/("76480 bar")=1.29xx10^(-5)`If N moles of `N_(2)` are prsent in 1 L of water (i.e., 55.5 moles), `x_(N_(2))=(n)/(n+55.5)~=(n)/(55.5)("as "ltlt 55.5)` `therefore""(n)/(55.5)=1.29xx10^(-5)"or"n=1.29xx10^(-5) xx 55.5" moles"=71.595xx10^(-5)" moles = 0.716 MILLIMOLES"` |
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| 48. |
If N_2 + 3H_2 hArr 2NH_3 has equilibrium constant K and 2N_2 + 6H_2 hArr 4NH_3 has equilibrium constant k', then k' = |
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Answer» `K^2` |
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| 49. |
If N_1,N_2,N_3…….. Are the number of molecules with molecular masses M_1,M_2,M_3………. Respectively, than mass average molecular mass is expressed: |
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Answer» `(sumN_iM_i^2)/(sumN_iM_i)` |
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