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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. |
Sodium carbonate is generally prepared by a process called ammonia soda process as follows : The above process is known as |
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Answer» OSTWALD process |
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| 2. |
Sodium carbonate exist as ....... |
| Answer» Solution :decahydrate `(Na_(2)CO_(3)*10H_(2)O)` | |
| 3. |
Sodium carbonate, Ba_(2)CO_(3) can be obtained by heating sodium hydrogen carbonate NaHCO_(3) as 2NaHCO_(3)(s) to Na_(2)CO_(3)(s) + H_(2)O(g) + CO_(2)(g) The essential data are : NaHCO_(3)(s) Na_(2)CO_(3)(s) + H_(2)O(g) + CO_(2)(g) Delta_(f)H^(@)-947.7-1130.9-393.51-241.82 (kJ"mol"^(-1)) |
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Answer» Solution :`2NAHCO(3)(s) to Na_(2)CO_(3)(s) + CO_(2)(g) + H_(2)O(g)` `Delta_(r)H^(@) = Delta_(f)H^(@) (NA_(2)CO_(3)) + Delta_(f)H^(@)(CO_(2)) + Delta_(f)H^(@)(H_(2)O) - 2Delta_(f)H^(@)(NaHCO_(3))` ` = -1130.9 + (-393.51) + (-241.82) - 2 xx (-947.7)` = `- 1766.23 + 1895.4 = 129.17 KJ"mol"^(-1)` `Delta_(r)S^(@) = S^(@)_(m)(Na_(2)CO_(3))+S_(m)^(@)(CO_(2)) + S_(m)^(@)(H_(2)O)- 2S_(m)^(@)(NaHCO_(3))` ` = 136.0 + 188.83 + 213.74 - 2 xx 102.1` ` = 538.57 - 204.2 = 334.37 J K^(-1) "mol"^(-1)` Now at equilibrium, `Delta_(r)G^(@) =0` so that `Delta_(r)G^(@) = Delta_(r)H^(@) - TDelta_(r)S^(@) = 0` `therefore T = (Delta_(r)H^(@))/(Delta_(r)S^(@)) = (129.17)/(334.37 xx 10^(-3)) = 386 K` `therefore` Reaction will be SPONTANEOUS above 386 K. |
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| 4. |
Sodium cannot be extracted by the electrolysis of brine solution because: |
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Answer» sodium liberated reacts with water to produce`NaOH+H_(2)` |
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| 5. |
Sodium benzoate gives Benzene on being heated with 'X'. Phenol gives Benzene on being heated wit‘Y'. 'X' and 'Y' are respectively, |
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Answer» SODALIME and copper |
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| 6. |
Sodium and potassium ions are chemically differ in which matter ? |
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Answer» For TRANSPORTATION of AMINO acid |
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| 7. |
Sodiumand potassiumions maintain _____ . |
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Answer» CONSTANT vpourpressureon eithersideof CELLWALL |
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| 8. |
Sodium and potassium are chemically similar, but their biological roles are different. Why? |
| Answer» Solution :The ability of SODIUM and potassium to penetrate into cell membranes is DIFFERENT. Their transport mechanisms and EFFICIENCY to active enzymes make them to DIFFER bilogically. | |
| 9. |
Sodium acetate + acetyl chloride gives : |
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Answer» `CH_(3)COOH` |
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| 10. |
Sodalime test for detection of N cannot be used for |
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Answer» acetamide |
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| 12. |
Sodalime is a mixture of .............. and ............. in the ratio.............. |
| Answer» SOLUTION :`NAOH , CAO , 3:1` | |
| 13. |
Soda extract or sodium carbonate extract is prepared for |
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Answer» testing all cations |
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| 14. |
Soda ash is chemcially |
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Answer» `Na_(2)CO_(3)` |
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| 15. |
Temporary hardness is due to |
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Answer» `Ca(HCO_3)_2` |
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| 16. |
Soap is the sodium salt of a long chain fatty acid, Sodium salt stearic acis is soluble in water, whereas calcium and magnesium salts are insoluble, so when soap is added to soft water, it dissolves and forms lather readily. Temporary hardness in water can be easily removed by boiling. Permanent hardness can be removed by the addition of washing soda, Calgon process, ion exchange process. Calgon contains |
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Answer» Solution :Hardness of `MgSO_4 = (6G)/(10^3g) = 6`ppm 6gin `10^6g` of watr hardness in terms of `CaCO_3 = 6 XX 100/120 = 5`ppm |
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| 17. |
Soap forms lather with soft water but does not form lather with hard water. Why? |
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Answer» Solution :HARD water forms scum/precipitate with SOAP. Soap containing SODIUM stearate `(C_(17)H_(35)COONA)` reacts with hard water to precipitate out Ca/Mg stearate. `2C_(17)H_(35)COONa_((AQ))+M_((aq))^(2+)to` `(C_(17)H_(35)COO)Mdownarrow+2Na_((aq))^+` ,M is Ca/Mg It is, therefore, unsuitable for laundry. |
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| 18. |
Soap essentially forms a colloidal solution in water and removes the greasy matter by |
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Answer» Absorption |
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| 19. |
Soap and synthetic detergents |
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Answer» LOWER the SURFACE tension of water |
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| 20. |
[SO_4^(2-) ]must be exceed what value to obtain aRaSO_4 (K_(sp) =4xx 10^(-11))ppt in 500 mLof a solutioncontaining 1xx10^(-4)"mole" of Ra^(2+)ions ? |
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Answer» ` 4 xx 10^(-7)M` ` (10 ^(_4) ) [SO_4^(2-) ] gt 4 XX1 0^(-11)RARR [SO_4^(2-)] gt4 xx 10 ^(-7) ` moles` = 4xx 10 ^(-7)xx 0.5 = 2 xx 10 ^(_7) ` |
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| 21. |
SO_(2) CI_(2) and CI_(2) are introduced into a 3L vessel. Partial pressure of SO_(2) CI_(2) and CI_(2) at equilibrium are I atm and 2 atm respectively. The value of K_(p)is 10 for the reaction SO_(2) Cl_(2) (g) hArr SO_(2) (g) + Cl_(2) (g).The total pressure in atm at equilibrium would be ____ |
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Answer» `K_(P)=(P_(SO_(2)).P_(Cl_(2)))/(P_(SO_(2)Cl_(2)))` `10=(PSO_(2).2)/(1) IMPLIES PSO_(2)=5` ATM Total PRESSURE at EQUILIBRIUM = `P_(SO_(2)Cl_(2))+P_(Cl_(2))+P_(SO_(2))=8` |
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| 22. |
SO_(2)CI_(2) harr SO_(2) +Cl_(2) (gascous): PCI_(5) harr PCI_(3) + Cl_(2) (gaseous) of some SO_(2) is removed from the above set of equillibria occuring in same closed container |
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Answer» Degree of dissociation of `SO_(2)Cl_(2)` decreases `:. Cl_(2)` is produced, HELVE equation 2 shifts backward i.e., `[PCl_(5)]` in CREASES `[PCI_(3)]` decreases |
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| 23. |
SO_2 pollution causes |
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Answer» CHLOROSIS in plants |
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| 24. |
SO_(2) , molecule is twice as heavy as O_(2)molecule. Hence at 25°C the ratio of the average kinetic energies of Sulphur dioxide and oxygen is |
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Answer» `1:1` |
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| 25. |
SO_(2) can be removed by using the followingSO_(2)+2H_(2)S rarr 2H_(2)O+3S S_(2)+Na_(2)SO_(3)+H_(2)O rarr 2NaHSO_(3) This is called |
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Answer» synergistic PROCESS (a) `H_(2)S` GAS which precipitates as SULPHUR `2H_(2)S+O_(2) rarr 2H_(2)O+3S` (b) `Na_(2)SO_(3)` which dissolves `SO_(2)` `Na_(2)SO_(3)+H_(2)O+SO_(2) rarr 2NaHSO_(3)`. |
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| 26. |
SO_2 and NO_2 cause pollution by increasing |
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Answer» Acidity |
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| 27. |
SO_(2) + 1/2O_2 + H_2O overset((HC+NO_2))underset(underset(underset("sootparticles")"(or)")"metal oxides") rarr H_2SO_4. |
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Answer» `Mn^(2+)` |
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| 28. |
SnO_2 is............ in nature |
| Answer» SOLUTION :AMPHOTERIC | |
| 29. |
SnCl_(2) + HCl + I_(2) rarr A+ B. The compounds (A ) and (B ) are |
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Answer» `SnI_(2), Cl_(2)` |
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| 30. |
SnCl_2 is angular, but HgCl_2 is linear. Why? Write their VSEPR notations. |
| Answer» Solution :`SnCl_(2)` has to BOND PAIRS and one Ione pair. Hence, it is ANGULAR `HgCl_(2)` has 2 bond pairs and no Ione pair. Hence it is linear. `SnCl_(2)` is denoted as `AB_(2)E`. `HgCl_(2)` is denoted as `AB_(2)`. | |
| 32. |
SnCl_(2) gives a precipitate with a solution of HgCl_(2). In this process, HgCl_(2) is |
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Answer» reduced |
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| 33. |
S_(N^2) reaction of an optically active haloalkane is accompanied by inversion of configuration at the asymmetric centre. Prove it. |
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Answer» SOLUTION :(i) `S_(N^2)`reaction of an optically active haloalkane (e.g., 2-bromo-octane) is accompanied by inversion of configuration at the ASYMMETRIC centre. (ii) When 2-bromooctane is heated with sodium hydroxide, 2-octanol is formed with inversion of configuration. (-) 2-bromo-octane on heating with sodium hydroxide gives (+) 2-octanol is formed in which-OH GROUP occupies a position opposite to what BROMINE had OCCUPIED in the optically active haloalkane. 
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| 34. |
Sn^(2+) and Sn^(4+) can be distinguished by how many of the following methods? (a) By passing H_(2)S in their solution (in acidic medium) (b) By addition of NaOH in their solution (c) By addition of excess NaOH in their solution (d) By addition of dil. HCI in their solution (e) By addition of HgCI_(2) solution in their solution |
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Answer» |
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| 35. |
Sn^(2+) and Fe^(3+) cannot coexist in the same solution. Why? |
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Answer» SOLUTION :Redox REACTION occurs between them. `2FE^(3+)+Sn^(2+)rarr Sn^(4+)+2Fe^(2+)` |
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| 36. |
Smoke is an example of |
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Answer» GAS DISPERSED in liquid |
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| 37. |
Smog is produced due to the spread of liquid particles and the evolution of the vapor in the air. |
| Answer» SOLUTION :TRUE STATEMENT | |
| 38. |
Small quanties of a soluton of compunds TX, TY and TZ are put into separate test tubes containing X,Y and Z solution TX does not react with any of these TY both with X and Z TZ reacts with X arrange the anions X^(-) Y^(-) and Z^(-) in decreasing ordr of their oxidation |
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Answer» SOLUTION :since TX not react with any of the solutionit meansthat X is least easily oxidized since TY reacts with both X and Z i.e `Y^(-)+XrarrX^(-)+YAND Y^(-)+Z rarrZ^(-)+Y` therefore `Y^(-)` is most easily oxidized since TZ reacts with only X i.e `Z^(-)+X rarr X^(-) +Z` therefore `Z^(-)` is more easily oxidized than `X^(-)` combining all the reult the DECREASING order of oxidationn of anons follows the order `Y^(-) gt Z^(-) gt x^(-)` |
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| 39. |
Slope of the plot between PV and P at constant temperature is |
| Answer» Answer :A::B::C::D | |
| 40. |
Slight shift of e- towards one of the atom in covalent bond produces effect called |
| Answer» Answer :A | |
| 41. |
Slakingof lime is a / an________ |
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Answer» exothermicreaction |
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| 42. |
Slaked lime is |
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Answer» CaO |
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| 43. |
Slag is formed by the reaction between |
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Answer» IMPURITIES and COKE |
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| 45. |
Size of orbital is determined by principal quantum number. |
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Answer» |
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| 46. |
Size of colloidal particles varies from |
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Answer» `10^(-9)` to `10^(-7)`m |
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| 47. |
Six valence electrons of oxygen are labelled as AB in 2s orbitals and CD , E, f in rp_x, 2p_z and 2p0_y orbitals repectively . If spin quantum number of A, Cm F is 1/2 the group of electron with three of the quantum numbers same are : |
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Answer» `[AB], [DEF]` `(AB)(C D) E F` It is th famous Schro dinger waver eqation . |
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| 48. |
Six grams each of magnesium and oxygen was allowed to react. Assuming that the reaction is complete, the mass of MgO formed in the reaction is |
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Answer» 42 grams |
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