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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 88601. |
A mixture of 1.65xx10^(21) molecules of X and 1.85xx10^(21) molecules of Y weighs 0.688g. If molecular mass of Y is 187. what is the molecular mass of X? |
| Answer» SOLUTION :`(Axx1.65xx10^(21))/(6.02xx10^(23))+(187xx1.85xx10^(21))/(6.02xx10^(25))=0.688,Aj=41.35` | |
| 88602. |
A mixture of 10 ml CH_(4), C_(2)H_(4) and C_(2)H_(2) has a vapour density of 11.3. When 30 ml of oxygen are sparked together over aqueous KOH, the volume contracts to 5.5 ml and then disappears when pyrogallol is introduced. If volumes are measured in the same conditions of pressure temperatre and humidity, calculate the composition of the original mixture. |
| Answer» Solution :`CH_(4)=4 ml, C_(2)H_(4)=3 ml, C_(2)H_(2)=3 ml` | |
| 88603. |
A mixture of 10ml CH_(4), C_(2)H_(4) and C_(2) H_(2) has a vapour of 11.3 When30ml of oxygenare sparked together over a aqueous KOH, the volume contracts to 5.5ml and then disappears when pyrogallol is introduced. If volume are measured in the same conditions of pressure temperature and humidity, calculate the composition of the original mixture. |
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Answer» Solution :Let the volume of `CH_(4)` at N.T.P. = x ml Let the volume of `C_(2) H_(4)` at N.T.P. = y ml Let the volume of `C_(2) H_(2)` at N.T.P. = z ml From question `x + y + z = 10 `.....(1) As we know that Weight of `CH_(4) + ` weight of `C_(2) H _(4) + ` weight of `C_(2) H _(2) = ` weight of MIXTURE `( 16x)/( 22400) + ( 28y )/( 22400) + ( 262)/( 22400) = ( 11.30)/( 11200) xx 10`.......(2) Now `underset( "x ml")(CH_(3)(g)) + underset(" 2x ml ")( 2O_(2)(g)) = CO_(2)(g) + 2H_(2)O(l)` `underset( "y ml ") ( C_(2) H_(4) ( g) ) + underset("3y ml ")(3O_(2)(g))HARR 2CO_(2)(g) + 2H_(2) O ( l )` `underset( " z ml") ( C_(2) H_(2)(g))+underset((5)/(2)Z ml )( (5)/(2) O_(2)(g) ) hArr 2CO_(2)(g) + H_(2)O(l)` Total volume of oxygen USED up in the reaction ` = ( 2x + 3y + ( 5)/( 2)) ml` But from question, Total volume of oxygen used up `= 30 - 5.5 = 24.5 ml` `:. 2x + 3y + ( 5)/(2) z = 24.5 `.......(3) Solving EUQATION (1), ( 2) and ( 3) we get x = 4,y = 3, z = 3 `:. CH_(4) = 4ML, C_(2) H _(4) = 3ml , C_(2) H_(2) = 3ml` |
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| 88604. |
A mixture of 1 mole each of FeSO_(4) and FeC_(2)O_(4) are taken then : |
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Answer» `n_("MOLES")` of `KMnO_(4)` required to oxidise `Fe^(2+)`to `Fe^(3+)` in acidic medium is 0.4 |
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| 88605. |
1-chloropropane when treated with alcoholic KOH gives: |
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Answer» 1-propene |
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| 88606. |
Amixture of 1-chloropropane and 2-chloropropane when treated with alcoholic KOH it gives : |
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Answer» 1-Propene |
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| 88607. |
A mixture of 1-chloropropane and 2-chloropropane when treated with alcoholic KOH gives |
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Answer» 1-propene `CH_3-undersetunderset(CL)(|)"CH"-CH_3+KOH to CH_3-CH=CH_2+KCl + H_2O` |
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| 88608. |
A mixture of 1-chloropropane and 2-chloropropane when treated with alcoholic KOH gives : |
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Answer» 2-Propene |
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| 88609. |
A mixture of 1^(@) , 2^(@) and 3^(@) amines can be separated by Hinsberg's reagent which is |
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Answer» BENZOYL chloride |
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| 88610. |
A mixture of 0.535g of ethanol and acetaldehyde when heated with Fehling's solution gave 1.2g of a red precipitate. What is the percentage of acetaldehyde in the mixture? (Cu = 63.5) |
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Answer» |
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| 88611. |
A mixture of 0.1 mol of Na_(2)O and 0.2 mol NaCl is dissolved in 1000g of H_(2)O. The boiling point of solution is [Kb(H_(2)O)=0.52 K.kg"mol"^(-1)] |
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Answer» `101.364` Oxidizing character of aqueous solution of `ClF_(3)` is DUE to PRESENCE of `HClO_(2)` |
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| 88612. |
A mixture is known to contain NO_(3)^(-) and NO_(2)^(-) before performing ring test for NO_(3)^(-). The aq. Solution should be made free of NO_(2)^(-). This is done by heating with |
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Answer» `NH_(4)Cl` |
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| 88613. |
A mixture having 0.5 mole KMnO_(4)and 0.5 mole K_(2)Cr_(2)O_(7)(in acidic medium) was completely reduced by 0.5 moles of a reducing agent (M^(@) = 132). Then equivalent mass of the reducing agent is : |
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Answer» `13.20` `5N + 6n = N (n_(f)) therefore n_(f)= 11 RARR E^(@) = (M^(@))/(n_(f)) = (132)/(11)=12` |
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| 88614. |
A mixture contains three amino acids A ( pl = 3.2 ) and B ( pl =5.7 ) and C ( pl = 9.7 ). When it is subjected to electrophoresis at pH = 7.7, in which direction will each component of the mixture move ? |
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Answer» A to ANODE , B and C to CATHODE |
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| 88615. |
A mixturecontains NaCland an unknownchloride MCI. (i) 1 g of thisis dissolved in water . Excess ofacidified AgNO_(3) solution is added to it 2.567 g ofwhite precipitateis formed (ii) 1- 0 gof theoriginal mixtureis heated of 300^(@) C. Some vapours comeout whichare absorbed in acidified AgNO_(3) solution . 1.314 g of a whiteprecipitate is obtained.Findthe molecular weightof the unknownchloride. |
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Answer» Solution :Supposethe molecular weight of MCI is M . Given that : `{:(NaCl = MCI overset(AgNO_(3))to AgCl),("(1 - x) g x g (say)2 . 567 g "):}` Applying POAC for CL atoms, moles of Clin NaCl + moles of Cl in MCI = moles of Cl in AgCl ` 1 xx ` moles of NaCl `+ 1 xx ` molesof MCl= `1 xx ` molesof AgCl `(1 - x)/( 58 . 5) + (x)/( M) = (2 . 567)/( 143 . 5 )`. . . (i) Now , futher of `300^(@) C ` MCIis supposed to undergo sublimation whileNaCldoesnot. We have, `{:(MCI underset(300^(@)C)overset(AgNO_(3))to AgCl),("x g1.341 g "):}` ApplyingPOAC for Cl atoms, moles of Cl in MCI= moles of Cl in AgCl `1 xx ` moles of MCI `= 1 xx ` molesof AgCl `(x)/( M) = (1 . 341)/( 143 . 5) "". . . (ii)` From equation (i) and (ii) , we get M = 53.5 `:.`mol. wt. of MCI= 53.5 |
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| 88616. |
A mixture contains F and Cl atoms. The removal of an electron from each atom of the sample requires 284 kJ while the addition of an electron to each atom of the mixture releases 68.8 kJ. Determine the % composition of the mixture. {:("(IE)" ,, " per atom " ,, " (E.A) per atom "), ("F" ,, 27.91 xx 10^(-27)k J ,, 5.53 xx 10^(-22) kJ), ("Cl" ,, 20.77 xx 10^(-27) kJ ,, 5.78 xx 10^(-22) kJ):} |
| Answer» SOLUTION : F = 37.81%, CL= 62.19 % | |
| 88617. |
A mixture contains four solid organic compounds A, B, C and D. On heating, only C changes from the solid to the vapour state. The compound C can be separated from the rest by :- |
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Answer» Distillation |
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| 88618. |
A mixture contains 61.2 % BaO, 28% CaO and 10.8% (silica) impurities. What volume in mL of 3.00 M would be required to react completely with 1 g of the mixture ? |
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Answer» MOLES =`0.612/153=0.004` wt of CaO=0.28 g moles of CaO=`0.28/56=0.005` mol `{:(BaO+,2HCl,toBaCl_2+H_2O),(0.004,0.004xx2,):}` `{:(CaO+,2HCl,toCaCl_2+H_2O),(0.005,2xx0.005,):}` number of moles of HCL REQUIRED =0.008+0.01=0.018 `MV_L=0.018` `3xxV_(ML)/1000=0.018` V=9 ml |
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| 88619. |
A mixture contains 64 g of dioxygen and 60 g of neon at a total pressure of 10 bar . The partial pressure in bar of dioxygen and neon are respectively (atomic masses O = 16 , Ne = 20) , |
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Answer» 4 and 6 |
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| 88620. |
A mixture containing two enantiomers in equal proportion is known as racemic mixture. |
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Answer» |
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| 88621. |
A mixture containing sulphides of copper and iron is called__ |
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Answer» mineral |
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| 88622. |
A mixture containing SiO_(2), NaCl and NH_(4)Cl is taken for separating the constituents . The suitable steps required for this are |
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Answer» Sublimation-DISSOLUTION-FILTRATION-crystallisation |
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| 88623. |
a mixturecontaining KClO_(3), KHCO_(3), K_(2) CO_(3) andKCl was heated, producingCO_(2) O_(2) and H_(2) Ogases accordingto thefollowingequations : {:(" "2KCl _(3)(s) to 2KCl(s) + 3O_(2)),(2KHCO_(3)(s) to K_(2)O(s) +H_(2)O(g)+2CO_(2)(g)),(" "K_(2)CO_(3)(s) to K_(2)O(s)+CO_(2)(g)):} The KCldoesnotreact under the conditionsof thereaction. If 100.0 g of the mixtureproduces 1 . 80 g of H_(2) O 13.20 g of CO_(2) and 4 . 0 g of O_(2). What was thecompositionof theoriginalmixture ? |
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| 88624. |
A mixture containing KCI and NaCI was dissolved and total chloride was determined by titration with silver nitrate. A sample weighing 0.3250 g required 51 mL of 0.1 N silver nitrate solution for complete reaction. The percentage of each salt in the sample will be: |
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Answer» `NACI = 25.77% , KCI = 74.23%` |
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| 88625. |
A mixture containing As_(2)O_(3) and As_(2)O_(5) required 20 mL of 0.05 N iodine solution for titration. The resultingsolution is then acidified and excess of Kl was added. The liberated iodine required 1.116 g hypo (Na_(2)S_(2)O_(3).5H_(2)O) for complete reaction. Calculate the mass of the mixture. The reactions are : As_(2)O_(3)+2l_(2)+2H_(2)OrarrAs_(2)O_(5)+4H^(+)+4l^(-) As_(2)O_(5)+4H^(+)+4l^(-)rarrAs_(2)O_(3)+2l_(2)+2H_(2)O " " (Atomic weight : As = 75) |
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| 88626. |
A mixture containing chlorides of sodium, calcium and zinc is electrolysed in presence of water. The productobtianed at cathode will be: |
| Answer» Answer :B | |
| 88627. |
A mixture containing As_(2)O_(3) and As_(2)O_(5) required 20 mL of 0.05 N iodine for titration.the resultingsolution is then acidifiedand excess of KI was added . The liberated iodine required 1.0 g of Na_(2)S_(2).5H_(2)Ofr complete reaction .Calculate the weight of the mixture .(As = 75 , O = 16 , S = 32 , Na =23) |
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Answer» Solution :M.e of `A_(2)O_(3)`= m.e of IODINE ` = 20 xx 0.05 = 1.0` WT. of `As_(2)O_(3) = (1.0)/1000 xx198/2 g = 0.0495 g ` `{:((As_(2)O_(3) + I_(2)to,As_(2)O_(5)+I^(-),E_(As_(2)O_(3))=198/4),(+6,+10,):}) ` `{:(" m.e of "As_(2)O_(5)+,"m.e of "As_(2)O_(5)=,"m.e of "I_(2)),(("produced by "As_(2)O_(3)),(" in the mixture"),),(,,= "m.e of"Na_(2)S_(2)O_(3)):}` or m.e of `As_(2)O_(3) + " m.e of "As_(2)O_(5)="m.e of " Na_(2)S_(2)O_(3)` `1. + " m.e of " As_(2)O_(5) = 1/(248//1) xx 1000` m.e of `As_(2)O_(5) = 4.032 ` Wt. of `As_(2)O_(5)` in the mixture ` = (4.032)/1000 xx 230/4 g ` `= 0.232 g ` `({:(AS_(2)O_(5)+I^(-) to, As_(2)O_(3)+I_(2),E_(As_(2)O_(5) =230/4)),(+10,+6,):})` ` :." wt. of " (As_(2)O_(3) + As_(2)O_(5)) = 0.0495 + 0.232 g = 0.2815 g ` |
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| 88628. |
A mixture containing 1.12 litres of H_(2) and 1.12 litres of D_(2) at NTP is taken inside a bulb connected to another bulb by a stopcock with a small opening. The second bulb is fully bulb is nw found to contain 0.05 g H_(2). Determine the percentage composition by weight of the gases in the seconds bulb. |
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Answer» |
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| 88629. |
A mixture contain 3.2g methanol (molecular mass =32 u) and 4.6 g ethanol (molecular mass =46 u) Find the mole fraction of each component. |
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Answer» Solution :Number of moles of methanol `n_1 = 3.2/32=0.1` Number of moles of ETHANOL `n_2 = 4.6/46=0.1` MOLE FRACTION ethanol`=0.1/(0.1+0.1)= 0.1/0.2= 0.5 because x_("Methanol") = 1- 0.5= 0.5` |
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| 88630. |
A mixture consiting of 80 mole per cent hydrogen and 20 mole per cent deuterium at 25^(@)C and a total pressure of 1 atm is permitted to effuse through a small orifice of area 0.20 m m^(2). Calculate composition of the initial gas that passes through. |
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Answer» |
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| 88631. |
A mixture consists of two metal oxides A (green) and B (white). Mixture was dissolved in 20 mL 2M NaOH solution contraining some H_(2)O_(2) to give a clear yellow solution leaving no residue. The above solution was separated into two parts. One part was acidified with acetic acid and then treated with (CH_(3)COO)_(2)Pb solution to give an yellow precipitate (C). C dissolves in dilute nitric acid forminga clear orange solution. Other part of solution was acidified with 2.0 M HCl and the 2M NH_(3) was added till the solution became alkaline and finally boiled. A white gelatinous precipitate (D) was obtained. D was then dissolved in dilute HCl and 6.0 M ammonium acetate was added. The solutions was finally treated with a few drops of alumiun reagent and made basic by adding ammonium carbonate. A red precipitate was obtained. Answer the following three questions based on the above information. Compounds A and B are respectively |
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Answer» `Cr_(2)O_(3)` and `Fe_(2)O_(3)` |
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| 88632. |
A mixture consists of two metal oxides A (green) and B (white). Mixture was dissolved in 20 mL 2M NaOH solution contraining some H_(2)O_(2) to give a clear yellow solution leaving no residue. The above solution was separated into two parts. One part was acidified with acetic acid and then treated with (CH_(3)COO)_(2)Pb solution to give an yellow precipitate (C). C dissolves in dilute nitric acid forminga clear orange solution. Other part of solution was acidified with 2.0 M HCl and the 2M NH_(3) was added till the solution became alkaline and finally boiled. A white gelatinous precipitate (D) was obtained. D was then dissolved in dilute HCl and 6.0 M ammonium acetate was added. The solutions was finally treated with a few drops of alumiun reagent and made basic by adding ammonium carbonate. A red precipitate was obtained. Answer the following three questions based on the above information. Compound C is most likely |
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Answer» `PbCr_(2)O_(7)` |
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| 88633. |
A mixture consists of two metal oxides A (green) and B (white). Mixture was dissolved in 20 mL 2M NaOH solution contraining some H_(2)O_(2) to give a clear yellow solution leaving no residue. The above solution was separated into two parts. One part was acidified with acetic acid and then treated with (CH_(3)COO)_(2)Pb solution to give an yellow precipitate (C). C dissolves in dilute nitric acid forminga clear orange solution. Other part of solution was acidified with 2.0 M HCl and the 2M NH_(3) was added till the solution became alkaline and finally boiled. A white gelatinous precipitate (D) was obtained. D was then dissolved in dilute HCl and 6.0 M ammonium acetate was added. The solutions was finally treated with a few drops of alumiun reagent and made basic by adding ammonium carbonate. A red precipitate was obtained. Answer the following three questions based on the above information. Compound D is most likely |
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Answer» `FE(OH)_(3)` |
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| 88634. |
A mixture consists (A) (red solid) and (B) (colourless solid) which gives lilac colour in flame. (a)Mixture gives black precipitate ( C) on passing H_(2)S (g). (b)( C) is soluble in aquaregia and on evaporation of aquaregia and adding SnCl_(2) gives greyish black precipitate (D). The salt solution with NH_(4)OH gives a brown precipitate. (i)The sodium extract of the salt with C Cl_(4)//FeCl_(3) gives a violent layer. (ii)The sodium extract gives yellow precipitate with AgNO_(3) solution which is insoluble in dilute ammonia solution. Identify (A) and (B), and the precipitates (C ) and (D). |
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Answer» (a)`(A)+(B)overset(H_(2)S(g))to(C)` BLACK precipitate. (b)`( C)underset("in aque regia")overset("soluble")to "soluble"overset("EVAPORATION")to"Residue"overset(SnCl_(2))to"Greyish black precipitate"(D)` `(A)+(B) overset(NH_(4)OH)to` brown precipitate.So second cation may be `Hg^(2+)` (i)Sodium carbonate extract of salt `overset(C Cl_(4)//FeCl_(3)) to` violent colour. (ii)Sodium extract of salt `overset(AgNO_(3))to "yellow precipitate" overset(NH_(3))to` soluble. So the anion may be `I^(-)` (a)`HgI_(2)+H_(2)Sto HgS (C )darr("black")+2HI` (b)`3HgS+6HCl+2HNO_(3)to3HgCl_(2)+2NO+4H_(2)O+S` `HgCl_(2)+SnCl_(2) to Hg darr (D) ("greyish black")+SnCl_(4)` `2KI(B)+HgI_(2)(A)toK_(2)[HgI_(4)]`(orange) `2K_(2)[HgI_(4)]+NH_(3)+3KOH to [HgOHg(NH_(2))I]darr`(brown) Sodium carbonate extract of salt contains `NaI` `2NaI+2Fe^(3+)overset(C Cl_(4))toI_(2)uarr("violet")+2Na^(+)+2Fe^(2+)` `I_(2)` dissolves in `C Cl_(4)` givingviolet colour solution. `AgNO_(3)+NaI toAgI darr("yellow")+NaNO_(3)` `AgI` is insoluble in ammonia solution. So,`(A),(B),( C)` and `(D)` are `HgI_(2),KI,HgS` and `Hg` respectively. `Mg^(2+)+2HCO_(3)^(-)`(from sodium salt)`toMg(HCO_(3))_(2)`(solube)`overset(Delta)toMgCO_(3)darr` (white)`+H_(2)O+CO_(2)` `Hg^(2+)` gives red precipitate of `Hgl_(2)` which dissolves in excess `KI`forming colourless `[Hgl_(4)]^(-)`(orange solution) `Pb^(2+)` gives yellow precipitate of `Pbl_(2).Cu^(2+)` gives white precipitate of `Cu_(2)I_(2)` with evolution of iodine. `[Zm(OH)_(4)]^(2-)overset(H_(2)O-"boiled")toZn(OH)_(2)darr("white")+2OH^(-)` `Zn(OH)_(2)` precipitate is readily soluble in excess of ammonia and in solutions of ammonium salts due to the formation of tetraamminezinc`(II)`. |
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| 88635. |
A mixture consistsof A (yellow solid)and B (colourless solid) whichgivesfilaccolour inflame. a. Themixture gives blackprecipitate C onpassingH_(2)S gas b. C issolublein aquaandon evaportationof aquaregainand adding SnCI_(2) givesgreyish -black precipitateD c. The saltsolutionwith NH_(4)OH givesa brownprecipitate . i. The sodiumextractof the salt with C CI_(4)//FeCI_(3) AgNO_(2) solutionwhichisinsoluble in NH_(3) Identify A and Band the precipitate C and D |
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Answer» Solution :`A: KI,B : HGI_(2) , C : HgS , D : Hg` Amixtureconsistsof a (yellow solid ) and B (colourless solid) which giveslilac colourin flame lilaccolour come frompiotassium ions . Mixturegives blackprecipitate Con passing `H_(2)S` gas C issolublein aquaregain it must be HgS .Oneveorationof aquaregainand adding `SnCI_(2)` it givea greyish-blackprecipitate D .This must be mercury .The saltsolutionwith `NH_(4)OH` gives a brownprecipitate.it mustbe iodide of Millon's basemercuriciodide .The sodiumextractof the salt with `C CI_(4)//FeCI_(3)` gives a violet LAYER .Thisconformiodide .Thesodium extractgives a yellowprecipitatewith `AgNO_(3)` solution which is insoloble in `NH_(3)` This alsoconform iodide `HgI_(2) + H_(2)S rarr underset(Black)(HgS darr )+ 2HI` `HgS overset("Aqua regia")rarr HgCI_(2)` (SOLUBLE) `HgCI_(2) overset(SnCI)rarr SnCI_(4) +underset(Black)(Hg)` ltbr? `2KI +HgI_(2) rarr underset("Nessler's reagent")(K_(2)HgI_(4))` `K_(2)HgI_(4) overset(NH_(3))rarr underset("Iodide of million's base")(H_(2)N-Hg-O-Hg-I)` With sodium extract: `2NaI +2FE^(3+) overset( C CI_(4))rarr I_(2) +2Na^(o+) +Fe^(2+)` `AgNO_(3) +NaI rarr AGi darr + NaNO_(3)` `AgI` is the yellow precipitate insoluble in ammonium hydroxide. |
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| 88636. |
A mixture consist of a yellow solid [A] and colourlesssolid[B]whichgiven lilac colourin flame. The miture given a blackprecipiate [C] on passing H_(2)S gas.Theprecipitate [C]is soluble in aqura regionandon evaporating and on addingSnCl_(2),gives greyish black precipitate [D]. Themisture solution on reacing with NH_(4)OH gives a brown precipiates.Thesodium extract ofthe mixturewith C Cl_(4)//FeCl_(3) givenviolet layer. The extract also givenyellow precicitate with AgNO_(3) solutionwhichis insoluble in NH_(3). The greyish black precipitate [D] is of |
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Answer» mercury |
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| 88637. |
A mixture consist of a yellow solid [A] and colourlesssolid[B]whichgiven lilac colourin flame. The miture given a blackprecipiate [C] on passing H_(2)S gas.Theprecipitate [C]is soluble in aqura regionandon evaporating and on addingSnCl_(2),gives greyish black precipitate [D]. Themisture solution on reacing with NH_(4)OH gives a brown precipiates.Thesodium extract ofthe mixturewith C Cl_(4)//FeCl_(3) givenviolet layer. The extract also givenyellow precicitate with AgNO_(3) solutionwhichis insoluble in NH_(3). The yellow solied [A]in the mixture is : |
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Answer» Stannous chlordie |
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| 88638. |
A mixture consist of a yellow solid [A] and colourlesssolid[B]whichgiven lilac colourin flame. The miture given a blackprecipiate [C] on passing H_(2)S gas.Theprecipitate [C]is soluble in aqura regionandon evaporating and on addingSnCl_(2),gives greyish black precipitate [D]. Themisture solution on reacing with NH_(4)OH gives a brown precipiates.Thesodium extract ofthe mixturewith C Cl_(4)//FeCl_(3) givenviolet layer. The extract also givenyellow precicitate with AgNO_(3) solutionwhichis insoluble in NH_(3). The blackprecipitate [c] is of : |
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Answer» Mercurous SULPHIDE |
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| 88639. |
A mixtrue of phenol and phthalic anhydride when heated with conc. H_(2)SO_(4) forms____which is used as an ____in acid-base tittrations. |
| Answer» SOLUTION :PHENOLPHTHALEIN, INDICATOR | |
| 88640. |
A mixiture of 0.3 mole of H_(2) and 0.3 mole of I_(2) is allowed to ract in a 10 lotre evacuated falsk at 500^(@)C. The reaction is H_(2)+I_(2)hArr2Hl, the K is found to be 64. The amount of unrecacted I_(2) at equilibrium is |
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Answer» `0.15` MOLE `x^(2)=64xx9xx10^(-4)` `x=8xx3xx10^(-2)=0.24` x is the amount of HI at equlibrium amount of `I_(2)` at equlibrium will be `0.30-0.24=0.06` |
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| 88641. |
A mixture CH_3 CH = NOH and CH_3 CH_2CH = NOH are allowed to undergo rearrangement in presenceof acid. The total products possible is |
Answer» 
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| 88642. |
A mixed oxide of iron and chromium , FeO.Cr_(2)O_(3) is fused with sodium carbonate in presence of air to form a yellow coloured compound (A). On acidification , the compound (A) forms an orange coloured compound (B) which is a strong oxidizing agent. (i)Identify the compounds (A) and (B) (ii) Write balanced chemical equation for each step. |
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Answer» Solution :`4FeO. Cr_(2)O_(3) + O_(2) rarr 2Fe_(2)O_(3) + 4Cr_(2)O_(3)` `4Na_(2)CO_(3)+ 2Cr_(2)O_(3) + 3O_(2) rarr 4Na_(2) CrO_(4) + 4CO_(2)] xx 2` `bar ( 4FeO. Cr_(2)O_(3)+ 8 Na_(2)CO_(3) + 7O_(2) rarr UNDERSET("Sodium chromate")underset((A))(8 Na_(2)CrO_(4)) + 2Fe_(2)O_(3)+ 8 CO_(2))` `2Na_(2)CrO_(4) + H_(2)SO_(4) rarr underset("Sodium dichromate")underset((B))(Na_(2)Cr_(2)O_(7))+Na_(2)SO_(4) + H_(2)O` |
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| 88643. |
A mixed solution of KOH and Na_(2)CO_(3) required 20 mL of N/20 HCl solutionwhen titrated with phenophthalein as indicator .Butthe same amountof solution when titrated with methylorange as indicator required 30 mL of the same acid . Calculate the amount of KOH and Na_(2)CO_(3) . |
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Answer» Solution :NEUTRALISATION reactions are `{:(KOH+HCl to KCl +H_(2)O),(Na_(2)CO_(3)+HCl to NaHCO_(3)+NaCl ),(NaHCO_(3)+HCl to NaCl +H_(2)O +CO_(2)):}}`phenolphthalein is used methyl orange is used . As DISCUSSED in the previous example we have with phenophthalein , m.e of 20 mL of N/20 HCl = m.e of KOH + m.e of `Na_(2)CO_(3)` or m.e or KOH + m.e of `Na_(2)CO_(3)` or m.e of KoH + m.e of `Na_(2)CO_(3) = 20 xx 1/20 = 1 ""...(1)` Now , with methyl orange , m.e of 30 mL of N/20 hCl m.e of HOH + m.e of `Na_(2)CO_(3) + " m.e of " Na_(2)CO_(3) = 20 xx 1/20 = 1 ""..(1)` Now , with methyl orange , m.e of 30 mLof N/20 HCl = m.e of KOH + m.e of `Na_(2)CO_(3) + " m.e of "NaHCO_(3)` produced . Since m.e of `Na_(2)CO_(3) `= m.e of `Na_(2)CO_(3) ` + m.e of `Na_(2)CO_(3)` or m.eof KOH + `2 xx ` m.e of `Na_(2)CO_(3) = 1.5 ""...(2)` Subtracting Eqn. (1) From Eqn. (2) , we get , m.e of `Na_(2)CO_(3) = 1.5 - 1 = 0.5` ` :. " EQUIVALENT of " Na_(2)CO_(3) = (0.5)/1000` ` :." wt of " Na_(2)CO_(3) = 106`) From eqn.s (3) and (1) , m.e of KOH ` = 1- 0.5 = 0.5` Equivalent of KoH ` = (0.5)/1000` WEIGHT of KOH = `(0.5)/1000 xx 56 = 0.28 g . `( eq. wt of KOH = 56) . |
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| 88644. |
A mixed solution of potassium hydroxide and sodium carbonate required 15 mL of an N//20 HCl solution when titrated with phenolphthalein as an indicator.But the same amount of the solution when titrated with methyl orange as an indicator required 25 mL of the same acid.The amount of KOH present in the solution is |
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Answer» 0.014 g `a+b/2=15xx1/20` 2a+b=1.5 ..(i) (in presence of PHENOLPHTHALEIN) `a+b=25xx1/20=1.25`…(ii)(in presence of Methyl ORANGE) by solving (i) & (ii) a = 0.25 Mili eq. mass of KOH=`0.25/1000xx56=0.014` GM |
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| 88645. |
A mixed oxide of iron and chromium FeO.Cr_(2)O_(3) is fused with sodium carbonate in the presence of air to form a yellow coloured compound (A). On acidification , the compound (A) forms an orange coloured compound (B) which is a strong oxidising agent. Identify (i) the compound A and B (ii) Write balanced chemical equation for each step. |
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Answer» Solution :The mixed OXIDE `FeO.Cr_(2)O_(3)` is the chromatic ore of iron also called ferro-chrome. It is written as `FeCr_(2)O_(4)`. Upon fusing with sodium carbonate in the presence of AIR, it give as yellow compound (A) which is sodium chromate. . `2FeCr_(2)O_(4)+8Na_(2)CO_(3)+underset((Air))(7O_(2)) overset("Fuse") to underset("(Yellow)")underset("SOD. chromate (A)")(8Na_(2)CrO_(4))+2Fe_(2)O_(3)+8CO_(2)` Sodium chromate (A) upon acidification with concentrated sulphuric acid changesto sodium dichromate (B) which has an orange colour. `underset("Sod.chromate")(2Na_(2)CrO_(4))+H_(2)SO_(4) to underset("(orange)")underset("Sod. dichromate (B)")(Na_(2)Cr_(2)O_(7))+Na_(2)SO_(4)+H_(2)O` |
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| 88646. |
A mixed oxide of iron and chromium FeO.Cr_(2)O_(3) is fused with sodium carbonate in the presence of air to form a yellow coloured compound (A). On acidification the compound (A) forms an orange coloured compound (B), which is a strong oxidising agent. Identify (i) the compounds (A) and (B). (ii) write balanced chemical equation for each step. |
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Answer» Solution :`underset((A))underset("Sodium CHROMATE")(4FeCrO_(4)+8Na_(2)CO_(3)+7O_(2)to 8Na_(2)CrO_(4)+2Fe_(2)O_(3)+8CO_(2))` `underset((B))underset("Sodium dichromate")(Na_(2)CrO_(4)+H_(2)SO_(4)toNa_(2)Cr_(2)O_(7)+Na_(2)SO_(4)+H_(2)O)` (A) is sodium chromate (YELLOW) and (B) is sodium dichromate (orange). |
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| 88647. |
A mixed ether on heating with dil. H_(2)SO_(4) under pressure gives mixture of two alcohols viz, methanol and ethanol. In this reaction , 80% yield of each alcohol is obtained. If the mass obtained for ethanol is 1.5 g. Calculate the mass of mixed ether used for thereaction. |
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Answer» 2.4 g |
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| 88648. |
A miscible mixture of C_6 H_6 + CHCl_3 can be separated by |
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Answer» Sublimation |
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| 88649. |
A minute quantity of cupric salt when heated on borax bead in reducing flame on bunsen burner, the colour of bead after cooling will be |
| Answer» Solution :Brown red | |
| 88650. |
A minute of copric salt is based on boraxhead in reducingflame of bansen burner, the colourof head aftercooling will be |
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Answer» Blue |
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