v. s. jagadeeshaiah.msc.mphil. lecturer in chemistry govt.p.u.college b.h.road,arsikere-573 103...

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V. S. JAGADEESHAIAH.MSc.Mphil.

LECTURER IN CHEMISTRYGOVT.P.U.COLLEGE

B.H.ROAD,ARSIKERE-573 [email protected]

9741-1234-68JAGADEESHAIAH, G.P.U.COLLEGE, ARSIKERE, 9741-

123468

mailto:[email protected]

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Industrially important compounds

V.S.JAGADEESHAIAH, G.P.U.COLLEGE, ARSIKERE, 9741-123468

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I.Manufacture of NaOH-Nelson’s procesNaCl Na+ +Cl-

H2O H+ + OH-

• A solution of sodium chloride in water contains Na+,Cl-,H+ and OH-

• During electrolysis, only H+ ion discharge at cathode .similarly only Cl- is oxidized at anode

• The solution become richer in Na+ & OH- ions


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Manufacture of ammonia-By Haber’s process

• Haber’s process involves the direct combination of N2 & H2

N2+ 3H2 2NH3+Heat• According to Le Chatelier’s principle ,The following

favorable conditions will give better yield of ammonia;i)Finely” catalystdivided “Feii)a promoter like Mo or K2O or Al2O3.

iii)a moderate temperature of 773K (5000C)iv)A high pressure of 200atm


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Steps involved

• Step-I; Compression• Step-II: Conversion • Step-III: Cooling• Step-IV: Recycling


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Manufacture of H2SO4

-by Contact process

• SO2(g)+O2 (g) 2SO3(g)+188kj• According to Le Chatelier’s principle, the

following favorable conditions are maintained;• i)Catalyst like V2O5 or Platinized asbestos or

Fe2O3.• ii)T=723K or 5000C• iii)P=2 to 3 atm


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Steps involved• Step-I: Production of SO2.

S(s)+O2(g) SO2(g) • Step-II; Purification of Gases

1)Dust chamber 2)Cooler3)Scrubber 4) Cottrell precipitator5)Drier: 6)Arsenic purifier7)Tyndall box

Step-III; Oxidation of SO2 to SO3.

SO2(g)+O2 (g) 2SO3(g)+188kj

Step-IV; Absorption


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Manufacture of K2Cr2O7

-From Chromite ore(FeOCr2O3 or FeCr2O4)

Step-I:Concentration of Chromite ore• Chromite ore is concentrated by Gravity

separation method.• Step-II:Roasting of concentrated ore.• 4FeO.Cr2O3 + 8Na2CO3 + 7O2

8Na2CrO4 +2Fe2O3 +8CO2


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Step-III: Coversion of Na2CrO4 to Na2Cr2O7

• Step-IV: Coversion of Na2Cr2O7 to K2Cr2O7

Na2Cr2O7 +KCl K2Cr2O7 +2NaCl


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1. “CO” under pressure reacts with solid NaOH to form

1) Na2CO3

2)HCOONa 3) Sodium corbonyl 4) SodiumAcetalide

Ans: CO +NaOH HCOONa(Sodium methanoate)


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2.During electrolysis of fused NaCl the anode reaction is

1)Oxidation of Na+ 2)Reduction of Na+ 3)Oxidation of Cl– 4)Reduction Cl–

Ans: (3) Oxidation of Cl–


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3.An unusual species is formed when Sodium metal is dissolved in liquid

ammonia

1) H2 2) NH4+

3) e– (NH3) 4) NH2 –

Ans: 3) e– (NH3)


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4.A solution of sodium metal in liquid ammonia is strongly reducing due to

the presence of 1)sodium atom2)sodium hydroxide3)sodium amide4)solvated electron

Ans:4)solvated electron


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5.In Nelson’s process for manufacture of NaoH the cathode and Anode are separated by asbestos diaphragm

1)To prevent reaction between NaOH and Cl2

2)To increase the yield of products 3)To prevent mixing of NaCl and NaOH4)To prevent reaction between

products formed during electrolysis.Ans:4)To prevent reaction between

products formed during electrolysis.


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6.Steam is passed through the tank in Nelson’s cells

1)To keep electrolyte warm 2)The keep pores of U-tube open 3)Both 4)None

Ans: 3)Both


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7.Electrolysis of brine produce

1)H2 and Cl2 2)Cl2 and Na

3)Cl2 and NaOH 4)Cl2, H2 and NaOH

Ans:4)Cl2, H2 and NaOH


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8.In the manufacture of NH3 by Haber’s process ,conditions for maximum yield

is1)Increasing and both temperature and

pressure 2)Decreasing both temperature and pressure 3)Increasing temperature and decreasing

pressure 4)Decreasing temperature and increasing the

pressure Ans:4)Decreasing temperature and increasing

the pressure


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9.Metallic hydroxide that can dissolve in excess of NaOH is

1) Al(OH)3 2)Ca(OH)2

3) Cu(OH)2 4)Mn(OH)2

Ans: 1) Al(OH)3


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10.Ammonia is manufactured by

1)Solvay’s process2)Nelson’s process3)Haber’s process 4)Contact procerss

Ans: 3)Haber’s process


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11.The drying agent for NH3 is

1) Na2CO3 2)Con.H2SO4

3) Quick lime (CaO)4) Anhydrous Calcium chloride

Ans:3)Quick lime (CaO)


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12.Effect of increase of temperature on equilibrium in

N2 + 3H2 2NH3 + Heat

1)Equilibrium is shifted to the left 2)Equilibrium shifted to the right3)Equilibrium is unaltered 4)Reaction rate does not change

Ans:1)Equilibrium is shifted to the left


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13. A white crystalline solid was heated with conc. H2SO4.Colourless

gaseous product was collected in a jar. The upper portion burned with a pale blue flame and the lower portion turns lime water milky .The crystalline solid

is 1)Na2CO3 2)HCOONa

3)H2C2O4 .2H2O 4)C12H22O11

Ans: 3)H2C2O4 .2H2O


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14.Oleum is

1)60% H2SO4.

2)Fuming sulphuric acid3)Oil of vitriol 4)dil.H2SO4.

Ans:2) Fuming sulphuric acid(H2S2O7)


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15.2SO2 + O2 2SO3 + 185.2 kJ

According to Le Chatelier’s principle, best yields of SO3 are obtained using

1)High pressure and high temperature 2)High pressure and low temperature 3)Low pressure and high temperature 4)Low pressure and low temperature

Ans: 2)High pressure and low temperature


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16. Reaction of conc. H2SO4 with sugar is called

1) Hydrolysis 2)Hydration 3) Dehydration 4)Decolourisation

Ans: 3)Dehydration


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17. What is the structure (geometry) of orange red product formed on reaction of K2Cr2O7 + conc H2SO4 + Rock salt

1)Trigonal planar 2)Square planar 3)Tetrahedral 4)Octahedral

Ans:3)Tetrahedral

Note: Chromyl chloride test is not answered by water insoluble salts like HgCl2,SnCl2,PbCl2..


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18.In Contact process of manufacture of sulphuric acid, Impurity oxides of

Arsenic is removed by

1)Al(OH)3 2)Cr(OH)3

3)Fe (OH)3 4)Fe2O3

Ans:3)Fe(OH)3


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19.In the manufacture of sulphuric acid by Contact process ,Tyndall box is used

to1)Remove impurities2)Filter dust particles3)Test the presence of dust particles4)Convert SO2 TO SO3.

Ans:3)Test the presence of dust particles


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20. When excess of PCl5 reacts with conc. H2SO4 it gives

1)Chloro sulphonic acid 2)Thionyl chloride 3)Sulphuryl chloride 4)Sulphurous acid

Ans: 3)Sulphuryl chloride (SO2Cl2)

VV.S.JAGADEESHAIAH, G.P.U.COLLEGE, ARSIKERE, 9741-123468

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21. In the reaction 2Ag +H2SO4

Ag2SO4 + SO2 +2H2O, sulphuric acid act as

1)An oxidising agent2)A reducing agent3)A catalyst4)A dehydrating agent

Ans:1)An oxidising agent


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22. When H2O2 is treated with cold acidified K2Cr2O7 solutions

containing ether. A Blue colour is obtained.This is due to

1)Chromium sulphate 2) K2CrO4

3)Perchromic acid 4) Chromium pentoxide

Ans: 3)Perchromic acid (CrO5) has blue colour in etherial solution


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23. A solutions of an inorganic salt has a lemon yellow colour. It changes to orange in acid medium and it turns yellow when it is made alkaline 1) FeCl3 2)Cu(NO3)2

3) K3F3(CN)6 4)K2CrO4

Ans: 4)K2CrO4


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24. The equilibrium H2O + Cr2O7

2– 2H+ + 2CrO42-

1)Exists in acidic medium 2)Exists in basic medium 3)Exists in neural medium 4)Does not exist

Ans: 1) Exists in basic medium (pH=10.3)


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25.The colour and composition of Chromyl chloride are

1)Orange red, CrO2Cl22)green, CrCl33)Orange red , CrO3

4)Dark red, CrOCl3

Ans: 1)Orange red, CrO2Cl2


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26.In the oxidation of hydrogen sulphide using acidified K2Cr2O7,The

oxidation state of sulphur changes by1)2 units

2)3 units3)1 unit

4)6 units

H2S S

-2 0

Ans: 2units


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27.Victor Meyer’s method can be used to determine the molecular mass of

1)Acetone2)Ethyl alcohol3)Ether4)All of these

Ans : 4)All of these


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28.A salt on heating with water liberates colourless gas which turned

lime water milky. The gas is1)Hydrogen chloride2)Hydrogen iodide3)Carbon dioxide4)Sulphur dioxide

Ans: 3)Carbon dioxide


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29.Nessler’s reagent is

1)An alkaline solution of HgCl2 and KI

2)A solution of ammonium hydroxide3)A solution of KI & sodium

thiosulphate4)A solution of Iodine

Ans: 1)An alkaline solution of HgCl2 & KI

HgCl2 + 4KI K2[HgI4] +2KClV.S.JAGADEESHAIAH, G.P.U.COLLEGE, ARSIKERE, 9741-123468

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30.Chromyl chloride test is used for confirming the presence of

1)Bromide ions2)Chloride ions3)Iodide ions4)Chromium ions

Ans:2)Chloride ions


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31.The test for unsaturation in organic compounds is decolourisation of

1)Bromine water2)Methyl orange3)Blue litmus solution4)Phenolphthlein

Ans: 1)Bromine water


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32.Which of the following reagent is used to distinguish ethene from ethyne?

1)Bromine water2)Alkaline KMnO43)Bromine in CCl44)Ammonical cuprous chloride(Cu2Cl2)

Ans: 4)Ammonical cuprous chloride (Cu2Cl2)


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33.The brown ring test for NO2-1 & NO3

-1 is due to the formation of complex ion with the formula

1)[Fe(H2O)5NO]2+

2)[Fe(H2O)6]2+.

3)[Fe(H2O)(NO)5]2+

4)[Fe(NO)(CN)5]2+

Ans:1)[Fe(H2O)5NO]2+


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34.The indicator used in the titration of sodium carbonate against hydrochloric acid is

1)Litmus paper2)Phenolphthalein3)Methyl orange4)Any of these

Ans: 3)Methyl orange


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35.Starch solution is used as an indicator in the titration of

1)KMnO4 v/s Oxalic acid

2)K2Cr2O7 v/s ferrous sulphate

3)H2SO4 v/s NaOH

4)Iodine against sodium thiosulphate

Ans: 4)Iodine against sodium thiosulphate


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36.In the titration between oxalic acid and acidified potassium permanganate ,the manganous salt formed catalyses the reaction .The manganous salt is

1)A promoter2)A positive catalyst3)An auto catalyst4)None of these

Ans: 3)An auto catalystV.S.JAGADEESHAIAH, G.P.U.COLLEGE, ARSIKERE, 9741-123468

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37.Since the ionosation potential of the alkali metals is low,they are identified

by flame test.The flame colour imparted by sodium is

1)Yellow 2)Red3)Violet 4)Orange

Ans: Yellow


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38.Phenol is heated with phthalic anhydride in the presence of

conc.H2SO4.The product gives pink colour with alkali. The product is

1)Salicylic acid 2)Fluorescein3)Phenolphthalein 4)Bakelite

Ans : 3)Phenolphthalein


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39.In the precipitation of third group basic radicals in qualitative

analysis,NH4Cl(s) is added before adding NH4OH to

1)Keep pH constant2)Decrease the concentration of OH- ions3)Increase in the concentration of Cl-

ions4)Increase the concentration of NH4

+ ions

Ans: 2)Decrease the concentration of OH- ions


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40.Which of the following doesnot reduce Benedict’s solution?

1)Glucose 2)Fructose3)Sucrose 4)Aldehyde

Ans: 3)Sucrose (Test for reducing sugars)


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41.Which of the following organic compounds answers both Iodoform

test and Fehling’s test?

1)Ethanol 2)Propanone3)Ethanal 4)Methanal

Ans: 3)Ethanal


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42.The test used for identifying peptide linkage in proteins is

1)Biuret test 2)Ninhydrin test

3)Molisch’s test 4)Borsche’s test

Ans: 1)Biuret test


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43.The reagent NH4Cl and NH4OH will precipitate

1)Ca2+ 2)Mg2+

3)Zn2+ 4)Fe2+

Ans: 4)Fe2+[Dirty green ppt. of Fe(OH)2]


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44.In the experimental determination of the rate constant for the hydrolysis of methyl acetate, the reaction mixture

is cooled in ice before carrying out titration. This is because

1)The end point is clear2)The hydrolysis occur uniformly3)The hydrolysis is arrested4)The hydrolysis is catalysed only at low

temperature

Ans:3)The hydrolysis is arrested


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45.An organic compound which produces bluish green coloured flame

on heating in presence of copper

1)Chlorobenzene 2)Benzaldehyde

3)Aniline 4)Benzoic acid

Ans: 1)Chlorobenzene


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46.The offensive smell produced when aniline is heated with chloroform and alcoholic KOH is due to the formation

of

1)2,4-dinitro compound2)Phenyl isocyanide3)Carbon dioxide4)An ester

Ans: 2)Phenyl isocyanide


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47.A solution of zinc sulphate produces a white precipitate on adding a few drops of NaOH.On adding excess of

NaOH,1)The precipitate remains insoluble2) The precipitate remains insoluble but

darkens3) The precipitate dissolves giving a

colourless solution4)The precipitate dissolves with the

formation of a deep green solution Ans: 3) The precipitate dissolves giving

a colourless solutionV.S.JAGADEESHAIAH, G.P.U.COLLEGE, ARSIKERE, 9741-123468

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48.Confirmatory test for NH4+ is

1)Chromyl chloride test2)Ethyl borate test3)Brown ring test4)Nessler’s reagent test

Ans: 4)Nessler’s reagent test


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49.The formula mass of Mohr’s salt is 392.The iron present in it is oxidised to Fe3+ by potassium permanganate.The

equivalent mass of Mohr’s salt is

1)392 2)31.53)278 4)156

Ans: 1)392Hint: The change in oxidation number is

“1”. Therefore Mol. mass = Eq.mass


JAGADEESHAIAH, G.P.U.COLLEGE, ARSIKERE, 9741-123468

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50.Volume of 0.6M NaOH required to neutralise 30 cm3 of 0.4MHCl is

1)45cm3

2)30cm3

3)20cm3

4)50cm3

Ans: 20cm3.

• Use relation N1V1=N2V2.

N2V2(HCl)

V1(NaOH)=

N1(NaOH)


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51.During the titration of KMnO4 with oxalic acid in acid medium ,the

oxidation number of Mn+7 changes to

1)+22)03)+54)+3

Ans: +2

KMnO4 MnSO4.

+7 +2


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52.In the reaction of NO3-1 ions with Copper turnings &

conc. H2SO4 ,the blue solution formed due to

1)Cu(HSO4)2 2)Cu(NO2)2

3)Cu(NO3)2 4)CuSO4

Ans: 3)Cu(NO3)2.

Hint: H2SO4 reacts NO3-1 ions to give HNO3.

“Cu” reacts with HNO3 to form Cupric nitrate

v. s. jagadeeshaiah.msc.mphil. lecturer in chemistry govt.p.u.college b.h.road,arsikere-573 103...

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