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. |
Solutions of two electrolytes 'A' and 'B' are diluted. The Lambda_(m)of 'B' increases 1.5 times while that of A increases 25 times. Which of the two is a strong electrolyte ? Justify your answer. |
| Answer» Solution : Electrolyte B is strong as on DILUTION, the NUMBER of ions remains the same. Only the interionic attraction decreases. THEREFORE the increase in `Lambda_(m)`is small. However in case of A, which is a weak electrolyte, dilution increases the ionization. Therefore `Lambda_(m)`increases much more. | |
| 2. |
Solutions of two electrolytes A and B each having a concentration of 0.2 M have conductivities 2xx10^(-2) and 4xx10^(-4)" S "cm^(-1) respectively. Which will offer greater resistance to the flow of current and why? |
| Answer» SOLUTION :`kappa=Gxx(1)/(a)=(1)/(R)(1)/(a),i.e., kappa PROP(1)/(R)`. Hence, B will OFFER GREATER resistance. | |
| 3. |
Solutions of two electrolytes 'A' and 'B' are diluted. The Lamda_(m) of 'B' increases 1.5 times while that of A increases 25 times. Which of the two is a strong electrolyte ? Justify your answer. |
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Answer» Solution :* Electrolyte .B. is strong as on dilution the number of ions remains the same, only interionic attraction decreases THEREFORE increase in `Lamda_(m)` is small. * Electrolyte B is strong electrolyte with respect to electrolyte A. * Electrolyte A is strong, so it gives complete ionization and no dilution, there no significant CHANGE is OBSERVED so, in value of `Lamda_(m)` there will be less difference. * Electrolyte B is weak, so it does not give complete ionization and on dilution, significant change is observed in number of ions. so, its `Lamda_(m)` value drastically increases (25 times) on dilution. These difference in the value of `Lamda_(m)` is due to increase in the distance between INTER ions which decrease in interionic attaction. "strong electrolyte gives less increase in `Lamda_(m)` on dilution." |
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| 4. |
Solutions in test tubes containing H_(2)O and aqueous NaOH can be differentiated with the help of |
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Answer» red LITMUS |
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| 6. |
Solutions distilled without change in composition at a temperature are called: |
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Answer» Atmorphous |
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| 7. |
Solutions are of "______________" types |
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Answer» three |
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| 8. |
Solution "X" contains Na_(2)CO_(3) and NaHCO_(3) 20 mL of X when titrated using methyl orange indicator consumed 60 mL of 0.1 M of X solution, when titrated using phenolphthalein consumed 20 ml. of 0.1 M HCI solution. The concentrations (in mol L^(-1) ) of Na_(2)CO_(3) and NaHCO_(3), in X are respectively |
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Answer» 0.01,0.02 `Na_(2)CO_(3) + HCI rarr NAHCO_(3) + NaCl` At the end point, there is no reaction between `NaHCO_(3)` and HCI. Volume of `Na_(2)CO_(3)` = Volume of HCl CONSUMED 20mL of 0.1 M=20mL of 0.1 M `:.`The concentration of `Na_(1)CO_(3)` in given solution 0.1M Since only half volume of HCl is consumed for titration of `Na_(2)CO_(3)` at phenolphthalein end point. The remaining half volume of HCI is used for complete NEUTRALIZATION of `Na_(2)CO_(3)` with methyl orange as indicator `NAHCO_(3) + HCI rarr NaCI + CO_(2)+ H_(2)O` `:.`Volume of HCI used for complete neutralization of `Na_(2)CO_(3)` in given solution = `2 xx20 ml = 40 ml` (ii) The remaining HCl used to neutralize `NaHCO_(3)` from the given X solution = 60– 40= 20 ml of 0.1 M From the equation Volume of `NaHCO_(3)`= Volume of HCl consumed 20 mL of 0.1M = 20 mL of 0.1 M `:.`The concentration of `NaHCO_(3)`in given X solution = 0.1M |
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| 9. |
Solution with reserve acidity and lakalinity are called :- |
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Answer» Isohydric solution |
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| 10. |
Solution S_1 contains 3g of urea per litre and solution S_2 contains 9g glucose per litre. At 298 K, the osmotic pressure of |
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Answer» `S_1` is GREATER than that of `S_2` |
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| 11. |
Solution (s) containing 40 gm NaOH is/are |
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Answer» 50GM of 80% (w/w) NAOH |
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| 12. |
Solution prepared by dissolving equal number of moles of HOCl (K_(a) = 3.2 xx 10^(-8)) and NaOCl in a buffer of pH |
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Answer» 3.2 G |
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| 13. |
Solution prepared by dissolving equal number of mole of HOCl ( K_s = 3.2 xx 10^-8) and NaOCl is a buffer of pH : |
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Answer» 8 |
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| 14. |
Solution of ZnS in dil HCl , when treated with NaOH solution , a white ppt.is formed which dissolves in excess of NaOH due to the formation of : |
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Answer» `ZN(OH)_2` `ZnCl_2 + 2NaOH to Zn(OH)_2 + 2NaCl` `Zn(OH)_2 + underset("EXCESS")(2NaOH) to underset("Sod zincate (soluble)")+ 2H_2O` |
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| 15. |
Solution of (X) in dil HCI + H_(2)O rarrwhite turbidily (X) overset(H_(2)S//HCI) toback ppt (Y),(Y) is solution in |
| Answer» Answer :C | |
| 16. |
Solution of sodium metal in liquid NH_3 is strongly reducing due to the presence of : |
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Answer» SODIUM atoms |
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| 17. |
Solution of SO_2 in water is known as: |
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Answer» Hydrosulphuric acid |
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| 18. |
Solution of following salt on heating with solid K_2Cr_2O_7 and conc. H_2SO_4 orange redvapours are evolved and resultant solution turn aquous NaOH solution yellow |
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Answer» NaBr |
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| 19. |
Solution of a salt in sulphanilicacid a naphithylamine give red ppt ,due to |
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Answer» `BR^(THETA)` |
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| 20. |
Solution of a salt in dilute H_(2)SO_(4) or acetic acid produces deep blue colour with starch iodide solution.The salt contains: |
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Answer» `Br^(-)` `2NO_(2)^(-)+3l^(-)+4CH_(3)COOH to I_(3)^(-)+2NOuarr+4CH_(3)COO^(-)+2H_(2)O` `I_(2)`+starch `to` blue colour |
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| 21. |
Solution of a salt in dil H_(2)SO_(4) produces deepblue colour with starchiodide solution .The salt contains |
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Answer» `BR^(THETA)` |
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| 22. |
Solution of a salt in dilute H_2 SO_4 produces deep blue colour with starch iodine solution. The salt contains |
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Answer» `Br^(-)` |
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| 23. |
Solution of a chemical compound 'X reacts with AgNO_3 solution to form a white ppt. 'Y which dissolves in excess of NH4OH to give complex 'Z'. When Z' is treated with dil HNO_3. Y reappears. The chemical compound 'X' may be : |
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Answer» NaBr |
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| 24. |
Solution of a mono basic acid has a pH =5 . If1 mL of it is diluted to 1 litre , what will be the pH of the resulting solution ? |
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Answer» 3.45 |
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| 25. |
Solution having the same osmotic pressure are called ……………..and they have same…………….. . |
| Answer» SOLUTION :ISOTONIC, MOLAR CONCENTRATION | |
| 26. |
Solution A + solution B rarr Fehling,s reagent. What are A and B ? |
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Answer» aq. Copper sulphate, aq. SODIUM potassium tartarate |
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| 27. |
Solution (A) is ideal and solution (B) is non-ideal with -ve deviation, which of the following are correct? |
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Answer» `DeltaH_("mix")=0, DeltaV_("mix")=0` for A |
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| 28. |
Solution A contains 7g//L MgCl_(2) and solution B sontains 7g//L of NaCl . At room temperature, the osmotic pressure of |
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Answer» SOLUTION A is grater that B |
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| 29. |
Solution 'A' contains acetone dissolved in chloroform and solution B' contains acetone dissolved in carbon disulphide. The type of deviations from Raoult's law shown by solutions A and B, respectively are |
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Answer» POSITIVE and positive |
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| 30. |
Solution A contains 7g/L MgCl_2 and solution B contains 7g/L of NaCl. At room temperature, the osmotic pressure of |
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Answer» Solution A is GREATER than B |
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| 31. |
Solution A contains 7g/L of MgCl_(2) and solution B contains 7 g/L of NaCl. At room temperature, the osmotic pressure of : |
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Answer» SOLUTION A is greater than B Concentration of `MgCl_(2)` solution `=(7)/(95)=0.074 M` HENCE, particles (IONS) in NaCl solution `(B) = 2xx0.119 = 0.238 M` Hence, particles (ions) in `MgCl_(2)` solution `(A)=3xx0.074 = 0.222 M` As the particles in solution B (NaCl) is more than in solution A, the osmotic pressure of solution B will be greater than that of solution A. |
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| 32. |
Solution (A) containing FeCl_(3) is separated from solution (B) containing K_(4)FE(CN)_(6) by a semipermeable membrane as shown below : {:("Solution (A)","Solution (B)"),(FeCl_(3),K_(4)Fe(CN)_(6)):} In FeCl_(3) on reaction with K_(4)[Fe(CN)_(6)] produces blue colour of Fe_(4)[Fe(CN)_(6)]_(3), the blue colour will appear in |
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Answer» A |
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| 33. |
Solution A contains 7 g/L MgCl_(2) and solution B contains 7 g/L of NaCl. At room temperature, the osmotic pressure of |
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Answer» solution A is greater than B `=(7)/(95)" mol L"^(-1)=(7xx3)/(95)"mol L"^(-1) " of ions "=0.22M` `7gL^(-1)NaCl=(7)/(23+35.5)M` `=(7)/(58.5)M=(7xx2)/(58.5)"mol L"^(-1)" of ions = 0.24 M"` As concentration of ions in NaCl solution is greater, NaCl soltuion (solution B) will have greater osmotic pressure. |
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| 34. |
Solution A, B, C and D are respectively 0.1M Glucose, 0.05M NaCl, 0.05M BaCl_2 and 0.1M AlF_3. Which one of the following pairs is isotonic ? |
| Answer» ANSWER :C | |
| 35. |
Solute when dissolved in water: |
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Answer» Decreases the vapour PRESSURE of WATER |
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| 36. |
Solute when dissolve in water |
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Answer» increases the VAPOUR PRESSURE of water |
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| 37. |
Solute A is a ternary electrolyte and solute B is non-electrolyte. If 0.1 M solution of solute B produces an osmotic pressure of 2P, then 0.05 M solution of A at the same temperature will produce an osmatic pressure equal to: |
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Answer» P |
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| 38. |
Solubilty product of Mg(OH)_(2),Cd(OH)_(2),Al(OH)_(3) and Zn(OH)_(2) are 4xx10^(-11),8xx10^(-6),8.5xx10^(-23) and 1.8xx10^(-14) resectively. The cation, that will precipitate first as hydroxide, on adding limited quantity of NH_(4)OH in a solution containing equimolar amount of metal cation, is : |
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Answer» `Al^(3+)` |
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| 39. |
Solubility (s) of CaF_(2) in terms of its solubility product is given as |
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Answer» `s = (K_(sp))^(1//3)` `CaF_(2) harr Ca^(2+) + 2F^(-)` Let solubility of `CaF_(2)` be s mol `"litre"^(-1)` Then `{:(CaF_(2) hArr,Ca^(2+),+,2F^(-)),(,s,,2s):}` Let `K_(sp) = [Ca^(2+)] [F^(-)]^(2) = (s) xx (2s)^(2) = 4S^(3)` `s = sqrt((K_(sp))/(4))`. |
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| 40. |
Solubility products of AI(OH)_(3) and An(OH)_(2) are 8.5 xx 10^(-23) and 1.8 xx 10^(-14) respectively. If both AI^(3+) and Zn^(2+) ions are present in a solution, which one will be precipitated first on addition of NH_(4)OH ? |
| Answer» Answer :A | |
| 41. |
Solubility product of silver bromide is 5.0xx10^(-13). The quantity of potassium bromide (molar mass taken as 120 g " mol"^(-1)) to be added to 1 litre of 0.05 M solution of silver nitrate to start the precipitation of AgBr is |
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Answer» `1.2xx10^(-10)g`<BR>`1.2xx10^(-9)g` `K_(sp) =([Ag^(+)][Br^(-)]` For precipitation to occur Ionic product `gt` Solubility product `[Br^(**)]** (K_(sp))/([Ag^(**)])**(5** 10^(-13))/(0.05) 10^(-11)` i.e. precipitation just STARTS when `10^(-11)` moles of KBR is added to `1//AgNO_(3)` solution `therefore` Number of moles of `Br^(-)` needed from `KBr=10^(-11)` `therefore` Mass of `KBr=10^(-11)xx120=1.2xx10^(-9) g` |
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| 42. |
Solubility product of silver bromide is 5.0 xx 10^(-13). The quantity of potassium bromide (molar mass taken as 120 g mol^(-1)) to be added to 1 litre of 0.5 M solution of silver nitrate to start the precipitation of AgBr is |
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Answer» `5.0 xx 10^(-8) G` `Br^(-) = (5 xx 10^(-13))/(0.05) = 10^(-11)` Conc. `= [KBr] = 10^(-11)` ltbgt Moles of KBr `= 10^(-11)` Weight of KBr `= 10^(-11) xx 120 xx 1.2 xx 10^(-9)g`. |
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| 43. |
Solubility product of Mg(OH)at ordinary temperature is 1.96 xx10^(-11). pH of a saturated soln. of Mg(OH)_2 will be |
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Answer» `10.53 ` ` K_(sp ) =([Mg]^(2+)[OH^(-)]^2)/( [Mg (OH)_2])= 1.96 xx 10^(-11)` ` x xx (2x)^2= 1.96 xx 10^(-11)` ( concentrationofsolid is UNITY ) `4x^3= 1.96 xx 10^(-11)` ` x=((1.96 xx 10^(-11))/(4) )^(1//3)` ` x= ( 4.9 xx 10^(-12))^(1//3)= 1.7 xx10^(-4)` So ` OH^(-) ` concentration`= 2XX 1.7 xx 10^(-4)` ` i.e.,[OH^-] = 3.4 xx 10^(-4)` Now `pOH=- log [OH^-]` `=- log [3.4 xx 10^(-4)]=4- 0.531= 3.469 ` ` therefore pH= 14 - 3.469= 10.531` |
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| 44. |
Solubility product of PbCl_(2) at 298 K is 1.0xx10^(-6). At this temperature solubility of PbCl_(2) in moles per litre is : |
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Answer» `(1.0xx10^(-6))^(1//2)` `K_(sp)=[Pb^(2+)][Cl^(-)]^(2)=(x)(2x)^(2)=4x^(3)` `THEREFORE x = ((1.0xx10^(-8))/(4))^(1//3)` `=(0.25xx10^(-6))1//3` |
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| 45. |
Solubility product of M(OH), is 10^(-14). What should be the concentration of M^(2+) in 0.1 M solution of NH_(4)OH, if NH_(4)OH gets 10% ionised? |
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Answer» `10^(-10)` `[OH^(-)]=(10)/(100)xx0.1=0.01` `[M^(+2)]=(K_(sp))/([OH^(-)]^(2))=(10^(-14))/([0.01]^(2))=10^(-10)` |
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| 46. |
Solubility product of Mg(OH)_(2) at ordinary temp. is 1.96 xx 10^(-11). pH of a saturated of Mg(OH)_(2) will be |
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Answer» 10.5 `K_(sp) = [Mg]^(2+) [ OH^(-)]^(2) = 1.96 xx 10^(-11)` `x xx (2 x)^(2) = 1.96 xx 10^(-11)` (concentration of solid is unity) `4x^(3) = 1.96 xx 10^(-11)` `x = ((1.96 xx 10^(-11))/(4))^(1//3)` `x = (4.9 xx 10^(-12))^(1//3) = 1.6 xx 10^(-4)` So, `OH^(-)` concentration `= 2 xx 1.6 xx 10^(-4)` i.e. `[OH^(-)] = 3.2 xx 10^(-4)` `= -log [3.2 xx 10^(-4)] = 4- 0.505 = 3.495` `:. pH = 14 - 3.495 = 10.505`. |
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| 47. |
Solubility product of Ba(OH)_2 is 4xx10^-9 its solubbility in water is |
| Answer» Answer :A | |
| 48. |
Solubility product of BaCl_(2) is 4 xx 10^(-9). Its solubility in moles/litre would be |
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Answer» `1 XX 10^(-3)` `:. S = 10^(-3) M`. |
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| 49. |
Solubility product of AgI at 25^@C is 4xx10^(-18)"mole"^2 //L^2 . The solubility of AgI in presence of 2xx10^(-4) M Kl solution at 25^@Cis approximately equal to : (in mol/L) |
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Answer» `8xx10^(-8)` `4xx10^(-18)=[Ag^+]xx2xx10^(-4)` `[Ag^+] = 2 XX 10^(-14)` M |
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| 50. |
Solubility product of AgCl is 1 xx 10^(-6) at 298 K. Its solubility in mole "litre"^(-1) would be |
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Answer» `1 xx 10^(-6)` mol/ litre `K_(sp) = x^(2), x = sqrt(K_(sp)), sqrt(1 xx 10^(-6)) = 1 xx 10^(-3)` mole/litre. |
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