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86301.

(A) XeO_3is a colourless explosive solid(R) XeO_3has pyramidal structure

Answer»

Both (A) and (R) are TRUE and (R) is the CORRECT EXPLANATION of (A)
Both (A) and (R) are true and (R) is not the correct explanation of (A)
(A) is true but (R) is false
Both (A) and (R) are false

Answer :B
Discussion
86302.

A yellow colour in NaCl crystals is due to ........

Answer»

EXCITATION of electrons in F-centres 
Reflection of LIGHT from `Cl^(-)` IONS on the SURFACE. 
Refraction of light from `Na^+` ions. 
All of the above 

Answer :A
Discussion
86303.

A yellow ppt, is formed when H_2S is passed through an acidified solution of:

Answer»

`Co^(2+)` ions
`CD^(2+)` ions
`CU^(2+)` ions
`NI^(2+)` ions

Answer :B
Discussion
86304.

(A) Xenon tetrafluoride molecule is denoted as AB_4E_4,where E is a lone pair(R) All AB_4type molecules have no dipolemoment, because of symmetrical tetrahedral structure.

Answer»

Both (A) and (R) are true and (R) is the CORRECT EXPLANATION of (A)
Both (A) and (R) are true and (R) is not the correct explanation of (A)
(A) is true but (R) is false
Both (A) and (R) are false

Answer :D
Discussion
86305.

(A) Xenon fluorides are well known and stable but the corresponding chlorides have not been reported.(R) Xe-F bond is more strong than Xe-Cl bond and F_2molecule has low bond dissociation energy than that of Cl_2molecule.

Answer»

Both (A) and (R) are true and (R) is the CORRECT EXPLANATION of (A)
Both (A) and (R) are true and (R) is not the correct explanation of (A)
(A) is true but (R) is false
Both (A) and (R) are false

Answer :A
Discussion
86306.

(A) XeF_4 reacts with SbF_5 to give a salt [Sb F_4]^(+) [XeF_5]^-(R) SbF_5acts as fluoride ion donor with XeF_4

Answer»

Both (A) and (R) are true and (R) is the correct EXPLANATION of (A)
Both (A) and (R) are true and (R) is not the correct explanation of (A)
(A) is true but (R) is false
Both (A) and (R) are false

Answer :D
Discussion
86307.

(A) XeF_2is a linear molecule (R) In XeF_2xenon undergoes sp^3dhybridization

Answer»

Both (A) and (R) are TRUE and (R) is the CORRECT explanation of (A)
Both (A) and (R) are true and (R) is not the correct explanation of (A)
(A) is true but (R) is false
Both (A) and (R) are false

Answer :B
Discussion
86308.

What are fibrous proteinsGive an example .

Answer»

Solution :(a)
(b)A nucleoside is obtainedwhen a nitrogenous base (purine or PYRIMIDINE) is attached to C, of a sugar (ribose or deoxyribose) by b-linkage.
(c) These are PROTEINS with thread like structure.they are insoluble in water but soluble in alkalies & acids. Eg: COLLAGEN, Kertain.
Discussion
86309.

A wrong statement related to the oxides of nitrogen.

Answer»

Oxides of nitrogen are generally stable
Nitrogen sesquioxide is regarded as a 1 : 1 mixture of nitrogendioxide and NITRIC oxide
NITROUS oxide as well as nitric oxides are examples of neutral oxides
`2NO_(2) HARR N_(2)O_(4)`. Both oxides represented here are diamagnetic

ANSWER :4
Discussion
86310.

A writing reaction with an aldehyde gives :

Answer»

ketone
a long chain FATTY acid
oldfin COMPOUND
epoxide

ANSWER :C
Discussion
86311.

A: Wrought iron is purest form of iron with respect to other forms. R: It has less than 0.5% carbon

Answer»

If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then MARK (1).
If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
If Assertion is true statement but Reason is FALSE, then mark
 If both Assertion and Reason are false STATEMENTS, then mark (4)

ANSWER :A
Discussion
86312.

(a) Write two difference between lyophilic and lyophobic colloids. (b) What is heterogeneous catalysis? Given an example. (c ) Give an expression for Freundlich Adsorption Isotherm.

Answer»

Solution :(a) For answer, CONSULT section table 8.
(b) For answer, consult section 10.
(c ) For answer, consult section 4.
Discussion
86313.

(a) Write the structures of main products when benzene diazonium chloride reacts with the following reagents : (i) H_(3)PO_(2)+H_(2)O (ii) CuCN//KCN (iii) H_(2)O (b) Arrange the following in the increasing order of their basic character in an aqueous solution : C_(2)H_(5)NH_(2),(C_(2)H_(5))_(2)NH,(C_(2)H_(5))_(3)N (c) Give a simple chemical test to distinguish between the following pair of compounds : C_(6)H_(5)-NH_(2) and C_(6)H_(5)-NH-CH_(3)

Answer»

Solution :(a) (i) `C_(6)H_(5)N_(2)Cl+H_(3)PO_(2)+H_(2)Ooverset(Cu^(+))underset("reduction")rarrC_(6)H_(6)+N_(2)+H_(3)PO_(3)+HCL`
`C_(6)H_(5)N_(2)Cloverset(CuCN)underset(KCN)rarrC_(6)H_(5)CN`
(III) `underset("Unstable")(C_(6)H_(5)CH_(2))-overset(+)Nequiv NCl^(-)overset(H_(2)O)rarrunderset("Benzylalcohol")(C_(6)H_(5)CH_(2)OH)+N_(2)uarr+HCl`
(b) In gaseous phase, basic character of amines increases with increase in number of electron releasing group, due to + 1 effect, so trend of basic character is `3^(@)gt2^(@)gt1^(@).`
But in aqueous phase, solvations of ammonium cation occurs by water molecules, greater the SIZE of ion, lesser will be the solvation, and lesser will be the stability of ion, so on combining + 1 effect and solvation effect, in aqueous phase trend changes to `2^(@)gt3^(@)gt1^(@),`
Discussion
86314.

[A] Write the total number of cyclic structural as well as stereoisomers possible for a compound with the molecular formula, C_(5)H_(10). [B] Write the total number of cyclic isomers possible for a hydrocarbon with the molecular formula C_(4)H_(6).

Answer»

Solution :(A) For a compound with molecular formula `C_(5)H_(10)` the ISOMERS are as follows.

Structure (vi) and (vii) are trans-isomers and are same, it can exist in d,l form.
So, total NUMBER of CYCLIC as well as stereoisomers POSSIBLE are seven.
(B) The possible cyclic isomers of the compound with molecular
Discussion
86315.

(a) Write the structures of main products when benzene diazonium chloride reacts with the following reagents : (i) H_(3)PO_(2)+H_(2)O (ii) CuCN/KCN (iii) H_(2)O (b) Arrange the following in the increasing order of their basic character in an aqueous solution : ""C_(2)H_(5)NH_(2), (C_(2)H_(5))_(2)NH, (C_(2)H_(5))_(3)N (c)Give a chemical test to distinguish between the following pair of compounds : ""C_(6)H_(5)-NH_(2)" and "C_(6)H_(5)-NH-CH_(3)

Answer»

Solution :(a)
(b) The increasing order of basic strength in aqueous solution is given as under :
`""C_(2)H_(5)NH_(2) lt (C_(2)H_(5))_(3)N lt (C_(2)H_(5))_(2)NH`
(c) To distinguish between `C_(6)H_(5)-NH_(2)" and "C_(6)H_(5)-NH-CH_(3)`.
`C_(6)H_(5)NH_(2)` on heating with chloroform and ethanolic potassium hydroxide forms PHENYL carbylamine which has a foul SMELL :
`C_(6)H_(5)NH_(2)+CHCl_(3)+3KOH overset("Heat")(rarr) underset(underset("carbylamine")("Phenyl"))(C_(6)H_(5)-NC)+3KCl+3H_(2)O`
`C_(6)H_(5)-NH-CH_(3)` does not give this test.
Discussion
86316.

(a) Write the structures of the main products where ethanal ( CH_(3) - CHO )reacts with the following reagents. (i) HCN (ii) H_(2) N - NH_(2) //H^(+)(iii) LiAlH_(4) (b) Arrange the following in increasing order of their reactivity towards nucleophilic additon reactions : C_(6) H_(5) COCH_(3), CH_(3) - CHO, CH_(3) - CO - CH_(3) (c ) Give a simple chemical test to distinguish between the following pair of compounds : CH_(3) CH_(2) CHOand CH_(3) CHO

Answer»

Solution :(a) (i) `CH_(3) - overset( O)overset( ||)(C ) - H rarr underset("Cyanohydrin")(CH_(3)-overset( OH)overset( |)(C ) - CN)`
(ii) `CH_(3) -overset( O)overset( ||)(C ) - H + H_(2) N- NH_(2) rarr `
(iii) `CH_(3) -overset( O) overset( ||)(C ) - H + 2[H] overset( LiAlH_(4))(rarr) CH_(3) CH_(2) OH`
(b) INCREASING order of reactivity towards NUCLEOPHILIC addition reaction is
`C_(6) H_(5) COCH_(3) lt CH_(3) COCH_(3) lt CH_(3) CH_(2) OH`
(c ) `CH_(3) CHO` gives a YELLOW precipitate of `CHI_(3)` with NaI `( NaOH//I_(2))` while `CH_(3) CH_(2) CHO` does not
`CH_(3) CHO + 3NaOI rarr underset ( "Iodoform")(CHI_(3)) + HCOONA + 2NaOH`
Discussion
86317.

(a) Write the structures of main products when aniline reacts with the following reagents : (i) Br_(2) water (ii) HCl (iii) (CH_(3)CO)_(2)O""//"pyridine" (b) Arrange the following in the increasing order of their boiling points : ""C_(2)H_(5)NH_(2), C_(2)H_(5)OH, (CH_(3))_(3)N (c) Give a simple chemical test to distinguish between the following pair of compounds : ""(CH_(3))_(2)NH" and "(CH_(3))_(3)N

Answer»

SOLUTION :(a)
(b) Increasing ORDER of the boiling points is :
`""(CH_(3))_(3)N lt C_(2)H_(5)NH_(2) lt C_(2)H_(5)OH`
(c) Distinguishbetween `(CH_(3))_(2)NH" and "(CH_(3))_(3)N` :
Thetwo compounds can be distinguished by reaction using benzene sulphonyl chloride `(C_(6)H_(5)SO_(2)Cl)`known as Hinsberg.s reagent.
`(CH_(3))_(2)NH` REACTS as under :

`""`(It is not ACIDIC and hence insoluble in alkali)
`(CH_(3))_(3)N` does not react with Hinsberg.s reagent because the former does not contain hydrogen.
Discussion
86318.

(a) Write the structures of A and B in the following reactions : (i) C_(6)H_(5)N_(2)^(+)Cl^(-)overset(CuCN)to A overset(H_(2)O//H^(+))to B (ii) CH_(3)COOH overset(NH_(3))underset(Delta)to A overset(NaOBr)to B (b) Write the chemical reaction of methyl amine with benzoyl chloride and write the IUPAC name of the product obtained. (c) Arrange the following in the increasing order of their pK_(b) values : C_(6)H_(5)NH_(2),NH_(3),C_(2)H_(5)NH_(2),(C_(2)H_(5))_(2)NH

Answer»

SOLUTION :(a) (i) `A=C_(6)H_(5)CN` PHENYL cyanide
B = `C_(6)H_(5)COOH` Benzoic acid
(II) `A=CH_(3)CONH_(2)` Acetamide
`B=CH_(3)NH_(2)` Methyl amine
(b) `CH_(3)NH_(2)+C_(6)H_(5)COCl to underset("N-Methylbenzamide")(CH_(3)NHCOC_(6)H_(5))`
(c) `(C_(2)H_(5))_(2)NH lt C_(2)H_(5)NH_(2)lt NH_(3) lt C_(6)H_(5)NH_(2)`
Discussion
86319.

a. Write the structure of histidine when pHlt1.82 and pHgt1.82. b. What is the pH range of neutral A A at the isoelectric point? c. The pH range in cellular fluid is 6 to 7. In what form (dipolar,cation, or anion) do the amino acids in each class predomiate in the cell?

Answer»

Solution :a.
b. All those amino acids with neutral `(R )` groups (e.g., hydrocarbon, alcohol, and amide) have `pl` in the same range `5.5-6.3.`
c. The amino acids are in the dipolar form because the cellular `pH` is very close to their `PI's`.
i. `pl` for acidic `A A's` are in the acidic range `(pH=6-7)`. they act as acids and exist mainly as anions.
ii. `pI` for basic A A's are in the basic range `(pH=6.7)`.they accept `H^(o+)` in the cell and exist mainly as cations.
iii. `pI` for very WEAKLY acidic `A A'a` e.g., cysteine (with its `SH`) and TYROSINE (with its phenolic `OH`), are in the acidic range `(pH=5-6)`. they are CLASSIFIED with neutral `A A's`
Discussion
86320.

a) Write the structure of P and Q? Name the reaction that gives the product P.

Answer»

Solution :BENZENE REACTS with carbon monoxide and hydrogen chloride in the presence of ANHYDROUS ALUMINIUM chloride and traced of cuprous chloride give benzoldehyde. This reaction is known as Getterman-Koch reaction.

BENZALDEHYDE followed by nitration will give m-nitor benzaldehyde
Discussion
86321.

(a) Write the structural formula of the main organic product formed when ethyl acetate is treated with twice the molar quantity of ethyl magnesium bromide and the reaction mixture is poured into water. (b) Give the structures of Grignard reagent and the substrate (aldehyde or ketone) that would react to form 2,4-dimethyl pentan-3-ol. (c ) By giving one chemical reaction prove that glycerol is an alcohol. (d) Give one specific example to prove that enzymes are very specific in their action . (e ) Write down the names and structures of two compounds obtained by dehydration of ethyl alcohol. (f) List the reagents commonly used to reduce carbonyl functional groups to alcohols. (g) Give the expected reduced product from the reaction of (a) CH_(3)COCH_(2)COOH,""(b)OHC CH_(2)C OO CH_(3) (c ) CH_(3)CH_(2)COCH_(2)CH_(2)Br," "(d)p-O_(2)N-C_(6)H_(4)CHO with (i) NaBH_(4),(ii)LiAlH_(4) (h) Give the product of the oxidation with MnO_(2) of : (a) CH_(3)CH_(2)CH=CHCH_(2)OH (b) C_(6)H_(5)CH_(2)OH (c )C_(6)H_(5)CH(OH)CH_(2)CH_(2)OH (d) CH_(3)CH=CHCH_(2)CH_(2)CH_(2)OH (i) Give the product of the oxidation with Jones reagent of : (a)CH_(3)CH=CHCH(OH)CH_(3)""(b)C_(6)H_(11)CH_(2)OH

Answer»


Solution :(e ) (i) Ethylene,`CH_(2)=CH_(2)` and (ii) Diethyl ether, `C_(2)H_(5)OC_(2)H_(5)`.
(f) `H_(2)//` catalyst, `LiAlH_(4),NaBH_(4),NaH`.
(g) (a) `(i) CH_(3)CH(OH)CH_(2)COOH`
(`ii) CH_(3)CH(OH)CH_(2)CH_(2)OH`
(b) (i) `HOH_(2)C CH_(2)COOCH_(3)" " (ii) HOH_(2)C CH_(2)CH_(2)OH`
(c ) (i)`CH_(3)CH_(2)CH(OH)CH_(2)CH_(2)Br`
(ii) `CH_(3)CH_(2)CH(OH)CH_(2)CH_(3)`
(d) (i) `p-O_(2)N-C_(6)H_(4)CH_(2)OH (ii)p-H_(2)N-C_(6)H_(4)CH_(2)OH`
`[LiAlH_(4),` being a more reactive reducing agent than `NaBH_(4)`, will also reduce-COOH and -COOR to corresponding primary alcohols. `LiAlH_(4)` also reduces `-NO_(2)` to `-NH_(4)` and many alkyl halides are reduced to alkanes. ]
(h) `(a) CH_(3)CH_(2)OCH=CHCHO""(b) C_(6)H_(5)CHO`
(c ) `C_(6)H_(5)COCH_(2)CH_(2)OH ""(d) `NO reaction
`[MnO_(2)` is a weaker oxidising agent and it selectively oxidises the -OH group of only allylic and benzylic `1^(@)` and `2^(@)` alcohols to give aldehydes. ]
(i) `(a) CH_(3)CH=CHCOCH_(3)""(b)C_(6)H_(11)CHO`
[The Jones reagent is a CHROMIC acid is aqueous acetone solution and sufficiently mild to oxidise alcohols into without affecting the double bonds. ]
(J) By using selective OXIDANT like,
(i) `K_(2)Cr_(2)O_(7) //` dil. `H_(2)SO_(4)` (ii) copper or silver catalyst at 523K
(ii) Pyridinium chlorochromate (PC C ) , made by mixing equimolar amounts of `CrO_(3)`, HCland pyridine in `CH_(2)Cl_(2)`
(iv) COLLINS reagent, made up of 1 mole of `CrO_(3)` to 2 mole of pyridine in `CH_(2)Cl_(2)(` as in `MnO_(2))`.
Discussion
86322.

(a) Write the steps and conditions involved in the following conversions : (i) Acetophenone to 2-phenyl-2-butanol (ii) Propene to acetone. (b) Describe simple chemical tests to distinguish between the following pairs of compounds :

Answer»

Solution : (a) (i) Acetophenone to 2-Phenyl-2-butanol :

( b) Add SODIUM metal. Diethyl ether will not REACT. Propanol will react to form hydrogen gas.
`CH_(3)CH_(2)CH_(2)OH + Na to UNDERSET("Sodium propanoate")(CH_(3)CH_(2)CH_(2)Ona + 1//2H_(2)uarr)`
Discussion
86323.

(a) Write the reactions involved in the following : (i) Hofmann bromamide degradation reaction. (ii) Diazotisation. (iii) Gabrieol phthalimide synthesis. (b) Give reasons : (i) (CH_(3))_(2)NH is more basic than (CH_(3))_(3)N in an aqueous solution. (ii) Aromatic diazonium salts are more stable than aliphatic diazonium salts.

Answer»

SOLUTION :(a) (i) Hofmann bromamide degradation reaction :
`underset("Amide")(R-overset(overset(O)(||))(C)-NH_(2))+Br_(2)+4NaOH rarr R-underset("Amine")(NH_(2))+Na_(2)CO_(3)+2NaBr+2H_(2)O`
(ii) Diazotisation :
`underset("ANILINE")(C_(6)H_(5)NH_(2))+NaNO_(2)+2HCl overset(273-278K)(rarr) underset(underset(underset("chloride")("diazonium"))("BENZENE"))(C_(6)H_(5)N_(2)Cl)+NaCl+2H_(2)O`
(iii) Gabriel phthalimide synthesis :

(b) (i) Due to COMBINED effect of the inductive effect of the methyl groups and solvation with water molecules, `(CH_(3))_(2)NH` is more basic than `(CH_(3))_(3)N`.

(ii) Aromatic diazonium salts are more stable because of the resonance that takes place as under :
Discussion
86324.

(a) Write the reactions involved in the following : (i) Etard reaction.(ii) Stephen reduction. (b) How will you convert the following is not more than two steps : (i) Benzoic acid to benzaldehyde.(ii) Acetophenone to benzoic acid. (iii) Ethanoic acid to 2-hydroxyethenoic acid.

Answer»

<P>

Solution :(a) (i) Etard reaction `:`

(ii) Stephen.s reduction `:`
`underset("Alkyl cyanide")(R-C -=N)underset(H_(2)O)overset(SnCl_(2)//HCL)(rarr) underset("Aldehyde")(R-CHO)`
(b) CONVERSIONS `:`
(i) Benzoic acid to benzaldehyde `:`
`underset("Acetophenone")(C_(6)H_(5) -overset(O)overset(||)(C ) - CH_(3) )underset(_CHI_(3))overset(NaOI)(rarr) C_(6)H_(5)COONaoverset(H_(3)O^(+))(rarr) underset("Benzoic acid")(C_(6)H_(5)COOH)`
(iii) Ethanoic acid to 2-hydroxyethanoic acid `:`
`underset("Ethanoic acid")(CH_(3)COOH)underset(I_(2))overset("Red P")(rarr) underset("2-Iodoethanoic acid")(CH_(3)- COOH)overset(NaOH)(rarr)underset("2-Hydroxyethanoic acid")(CH_(2)(OH)COOH)`
Discussion
86325.

(a) Write the product(s) in the following reactions : (i) (iii) CH_(3)-CH=CH-CN overset("(a) DIBAL - H")underset("(b) "H_(2)O)rarr? (b) Give simple chemical tests to distinguish between the following pairs of compounds: (i) Butanal and Butan-2-one (ii) Benzoic acid and Phenol Or (a) Write the reactions involved in the following : (i) Etard reaction (ii) Stephen reduction (b) How will you convert the following in not more than two steps: (i) Benzoic acid to Benzaldehyde (ii) Acetophenone to Benzoic acid (iii) Ethanoic acid to 2-Hydroxyethanoic acid

Answer»

Solution :(i)
(III) `CH_(3)-CH=CH-CHO`
(b) (i) Tollen.s reagent test : Add ammoniacal solution of silver NITRATE (Tollen.s Reagent) in both the solutions. Butanal GIVES silver mirror whereas Butan-2-one does not.
(ii) Add neutral `FeCl_(3)` in both the solutions, phenol forms violet colour but benzoic acid does not.
(a)(i)
(ii) Stephen reaction
`RCN+SnCl_(2)+HCl rarr RCH = NH overset(H_(3)O^(+))rarr RCHO`
Or
`RCN overset("(i) "SnCl2+HCl)underset((ii)H_(3)O^(+))rarrRCHO`
(b) (i)`RCNoverset((i) SnCl2+HCl)underset((ii)H_(3)O^(+))rarr RCHO`
(ii)
Discussion
86326.

a.Write the reaction of EtOH with (i) KNH_(2) (ii) aq.KOH (iii) Potassium ethynide. b.Complete the following reaction: c.Why is methanol more toxic than ethanol ? How is a methanol Poisoned patient treated ? d.How does the ingestion of ethanol in low and high concentration affects the central nervous system ?

Answer»

Solution :a.
i. `K^(o+)NH_(2)^(o+) + EtOH rarr NH_(3) + etO^(-) K^(o+)`
ii.`K^(o+)O^(-)H + EtOH` `H_(2)O + EtO^(-)K^(o+)`
iii.`HC-=N^(-)K^(o+) + EtOH rarr HC-=CH + EtO^(-)K^(o+)`
b.
c.MeOH `overset ([O]) rarr` `CH_(2)=O` `overset([O]) rarr` HCOOH
EtOH `overset ([O]) rarr` MeCH=O `overset ([O]) rarr` MeCOOH
The merabolism (biological oxidation) of both alcohols in the BODY produces corresponding aldehyde (methanal and ethanal) followed by acid (methanoic and ethanoic acid). The product from methanol is much more toxic than the product from ethanol. Methanal and methanoic acid may cause bindness and deth. A methanol posisoned patient is treated by giving intravenous infusion of diluted ethanol. The enzyme responsible for oxidation of aldehyde `(HCHO)` to acid is swamped, allowing KIDNEYS to excreate methanol.
d.Ingestion of ethanol on the CNS (central nervous system). In small or moderate amount, it affects judgement and lowers inhibitions. Higher amount causes nausea and loss of consciopusness and interferes with spontaneous respairation and can be fatal.
Discussion
86327.

(a) Write the principle of vapour phase refining. ltbr. (b) Write the role of dilute NaCN in the extraction of silver. ltBrgt (c) What is the role of collectors in the froth floatation process? Give an example of a collector.

Answer»

Solution :(a) Vapour phase refining: The crude metal is freed from impurities by first converting it into SUITABLE VOLATILE compound by HEATING it with a specific reagent at a lower temperature and then decomposing the volative compound at some higher temperature to give the pure metal.
(b) NaCN oxidises silver to form soluble COMPLEX of cyanide while the impurities remain UNAFFECTED which are filtered off.
`4Ag+8CN^(-)+2H_(2)O+O_(2)to4{Ag(CN)_(2)]^(-)+4OH^(-)`
this process in known as leaching.
(c) Collectors enchance the non-wettability of the ore particles. Example, Pine oil, Xanthates.
Discussion
86328.

a. Write the product of the followig reactions: (ii) 2C_(6)H_(5)CHO+"Conc". NaOHto (iii) CH_(3)COOHoverset(Cl_(2)//P)(to) b. Give simple chemicaltests of distinguish between the following pairs of compounds: (i) Benzaldehyde and benzoic acid (ii) Propanol and propane.

Answer»

Solution :
b. (i) Add `NaHCO_(3)` benzoic acid will give brisk EFFERVESCENCE whereas BENZALDEHYDE will not give this test. (Or any other test)
(ii) Add Tollen.s reagent, propanal will give silver MIRROR, whereas propanone will not give this test. (or any other test)
Discussion
86329.

(a) Write the principle of electrolytic refining. (b) Why does copper obtained in the extraction from copper pyrites bave a blistered appearance? (c) What is the role of depressants in the froth floatation process?

Answer»

Solution :(a) Impure metal is converted into block to form anode while cathode is made up of pure strip of the same metal suspended into electrolyte of a soluble salt of the metal when electric current is passed, metal ions from electrolyte are deposited at the cathode in the form of pure metal while an equivalent amount of metal dissolves from the anode and goes into the electrolyte solution as metal ion.
(b) In thhe extraction of copper from copper pyrites, molten metal is poured in sand moulds and when metal cools, dissolved `SO_(2)` escapes. some of the gas bubbles are entrapped during solidification giving blister like appearance to the metal.
(c) Depresent prevents one TYPE of sulphide ore particles from FORMING the FROATH with air bubbles. Example, NaCN is used as depresent to separate lead sulphide ore from zinc sulphide ore.
`4NaCN+ZnStoNa_(2)[Zn(CN)_(4)]+Na_(2)S`
Discussion
86330.

(A) Write the possible structural isomers of the molecular formula C_(7)H_(16). (B) Writethe condensed and bond line structural formulae for all the possible isomers having the molecular formulae C_(4)H_(6).

Answer»

SOLUTION :(A) `C_(7)H_(16)`has nine isoemrs.
Discussion
86331.

(A) Write the possible isomers of the formula C_(5)H_(10)O_(2). (B) Draw the structures of all isomeric ethers. Corresponding to the moecular formula, C_(5)H_(12)O.

Answer»

Solution :(A) (a) Carboxylic acids:
(i) `CH_(3)CH_(2)CH_(2)CH_(2)COOH` (ii) `CH_(3)-underset(CH_(3))underset(|)(CH)-CH_(2)COOH`
(iii) `Ch_(3)-Ch_(2)-underset(CH_(3))underset(|)overset(*)(CH)-COOH` (iv) `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-COOH`
(b) Esters: (i) `CH_(3)CH_(2)CH_(2)COOCH_(3)` (ii) `CH_(3)CH_(2)COOCH_(2)CH_(3)`
(iii) `CH_(3)COOCH_(2)CH_(2)CH_(3)` (iv) `CH_(3)COO-underset(CH_(3))underset(|)(CH)-COOH`
(c) Hydroxyladehydes and (d) Hydroxyketones, etc.
(B) D.B.E.=1/2[5(4-2)+12(1-2)+1(2-2)]+1=0
Since D.B.E.=0 therefore `C_(5)H_(12)O` representes only saturated ethers, Its POSSIBLE isomers are:
(i) `CH_(3)CH_(2)CH_(2)-O-CH_(2)CH_(3)`
(ii) `CH_(3)underset(CH_(3))underset(|)(CH)-O-CH_(2)CH_(3)`
(iii) `CH_(3)CH_(2)CH_(2)CH_(2)-O-CH_(3)` (iv) `CH_(3)CH_(2)CHCH_(3)`
(V) `CH_(3)underset(CH_(3))underset(|)(C)HCH_(2)-O-CH_(3)` (vi) `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-O-CH_(3)`
Thus, there are total six isomers.
Discussion
86332.

(a) Write the partial structure of (i) Neoprene (ii) Terylene (Dacron) (iii) Nylon-6 (b) Explain the preparation of Buna-N with equation.

Answer»

Solution :(a) (i)
(III)
(B) 1, 3-butadiene and a crylonitrile is TREATED in presence of peroxide to GET Buna-N
Discussion
86333.

a. Write the organic compound formed in the following equations: (iii) CH_(3)-Mg-Br+CO_(2)underset(H_(3)O^(+))overset("Dry ether")(to) b. Explain HVZ (Hell Voldhard-Zelinsky) reaction with equation.

Answer»

SOLUTION :
(iii) `CH_(3)COOH`
b. Carboxylic acid having an `alpha`- hydrogen are halogenated at `alpha`- position on treatment with chlorine or bromice in the PRESENCE of Red P to give `alpha`-halocaroxylic acid.
`R-CH_(2)-COOHunderset(H_(2)O)overset(X_(2)//"Red"P)(to)R-underset(X)underset(|)(CH)-COOH`
(Where `x=Cl,Ba`)
Discussion
86334.

(a) Write the mechanism of the following reaction : 2CH_(3)CH_(2)OH overset(H^(+))rarr CH_(3)CH_(2)-O-CH_(2)CH_(3) (b) Write the equation involved in the acetylation of salicylic acid.

Answer»

Solution :(a) `2CH_(3)CH_(2)OH OVERSET(H^(+))rarr CH_(3)CH_(2)OCH_(2)CH_(3)`
MECHANISM :
Step 1. `CH_(3)CH_(2)-overset(* *)underset(* *)O-H+H^(+)rarr CH_(3)-CH_(2)-overset(H)overset(* *)underset(* *)(""^(+)O)-H`
Discussion
86335.

(a) Write the mechanism of the following reaction : 2CH_(3)CH_(2)OH (H^(+))/(413K)CH_(3)CH_(2)OCH_(2)CH_(3)+H_(2)O (b) Write the preparation of phenol from cumene.

Answer»

SOLUTION :(a) Step 1. Protonation of alcohol
`CH_(3)-CH_(2)-overset(* *)underset(* *)O-H+H^(+)toCH_(3)-CH_(2)overset(" "+)_overset(H)overset(* *)underset(* *)O-H`
Step 2. Addition of second alcohol molecule to the protonated alcohol

Step 3. Removal of proton

(b) Cumene is oxidised in the presence of air to give cumene hydroperoxide. It is converted to PHENOL and acetone by treating it with dilute acid.
Discussion
86336.

(a) Write the mechanism of acid catalysed dehydration of ethanol to ethene. (b) How does anisole react with bromine in ethanoic acid? Give equation.

Answer»

SOLUTION :(a)Step 1: Protonation of ALCOHOL.

Step 2: FORMATION of corbocation by loss of water.

Step 3 : Formation of ethane by loss of PROTON.

(b)
Discussion
86337.

(a) Write the IUPAC names of all the possible structural isomers of C_(4)H_(9)Br. Point out opticaly active isomer, if any. (b) Write the structural formulae and IUPAC names of two optically active halides containing five carbon atoms each in their molecules.

Answer»

SOLUTION :2-chloropentane and 2-chloro-3-methylbutane
Discussion
86338.

(a) Write the IUPAC of the isomer of the following complex : [Pt(NH_(3))_(2)Cl_(2)] (b) Write the formula of the following : Tetraammineaquachloridocobalt (III) nitrate.

Answer»

Solution :(a) CIS or trans-diamminedichloridoplatinum (II).
(b) `[Co(NH_(3))_(4)(H_(2)O)Cl](NO_(3))_(2)]`
Discussion
86339.

(a) Write the IUPAC name of the isomer of the following complex : [Co(NH_(3))_(5)Cl]SO_(4) (b) Write the formula for the following : Diamminechloridonitrito-N-platinum (II)

Answer»

Solution :(a) Ionization isomer is `[Co(NH_(3))_(5)SO_(4)]CL`, pentamminesulphatocobalt (III) chloride (b) `[Pt(NH_(3))_(2)Cl(NO_(2))]`
Discussion
86340.

(a) Write the IUPAC name of the following complex : [Co(NH_(3))_(4)Cl(NO_(2))]Cl (b) Write the formula for the following : Dichloridobis (ethane-1, 2-diamine) cobalt (III) chloride.

Answer»

Solution :(a) Tetraamminechloridonitrito-N-cobalt (B) `[CoCl_(2)(EN)_(2)]Cl]`
Discussion
86341.

a) write the IUPAC name of K_3 [Cr (C_2 O_4)_3]. b) give the facial (fac) and meridional (mer) isomeric structures of [Co (NH_3)_3 (No_2)_3].

Answer»

SOLUTION :(a)POTASSIUM trioxalatochromate(III). (B)
Discussion
86342.

Give the IUPAC name of K_3 [Cr(C_2 O_4)_3]

Answer»

SOLUTION :(a) POTASSIUM trioxalatochromate (III)
(B)
Discussion
86343.

(a) Write the IUPAC name of [Co(NH_3)4(H_2O)Cl]Cl_2 (b) Explain linkage isometrism with example.

Answer»

SOLUTION :Tetraammineaquachloridocobalt (III) CHLORIDE.
(b) Two or more compounds having the same molecular formula but differing in the mode of attachment of ligands to the central metal ion are called LINKAGE isomers. The phenomenon is called linkage isomerism
`[Co(NH_3)_5NO_2]Cl_2 and [Co(NH_3)_5ONO]Cl_2` yellowish brown red.
Discussion
86344.

Write the IUPAC name of : [Co(NH_(3))_(4)(H_(2)O)Cl]Cl_(2)

Answer»

SOLUTION :(a) Tetraammineaquachloridocobalt(III) chloride
(b) Coordination compounds having same molecular formula but differing in the mode of ATTACHMENT of LIGAND to the central metal ion or ATOM is called Linkage ISOMERISM.
Example : `[Co(NH_3)_5(NO_2)C_12` and `[Co(NH_3)_5(ONO)]CI_2`
Discussion
86345.

(a) Write the IUPAC name and hybridisation of the complex [CoF_(6)]^(3-). [Given : Atomic number of Co = 27] (b) What type of isomerism is shown by the complex [Co(en)_(2)Cl_(2)]^(2+) ? Name the structure of an isomer of this complex which is optically active.

Answer»

Solution :(a) IUPAC NAME : Hexachloridocobaltate (III) ion.
(b) GEOMETRICAL isomerism is SHOWN by `[CO(en)_(2)Cl_(2)]^(2+)`.
cis - `[Co(en)_(2)Cl_(2)]^(2+)` is optically active.
Discussion
86346.

(a) Write the Haworth structure of maltose. ( b ) Give an example for (i) Globular proteins. (ii) naturally occuring optically inactive amino acid. ( c ) Name the nucleic acid which is responsible for genetic information.

Answer»

SOLUTION :(a)
( b) (i) G obuar protein - Haemogcobin or ALBUMIN.
(II) Glycine.
( c ) DNA.
Discussion
86347.

(a) Write the Haworth's structure for lactose. (b) Give an example for the following: (i) Naturally occurring optically inactive a-amino acid. (i) Nitrogen base only found in R.N.A. (c ) Name the disease caused by the deficiency of vitamin A.

Answer»

Solution :(a)

(B) (i) GLYCINE
(II) URACIL.
(c ) Night blindness
Discussion
86348.

(a) Write the Haworth structure of maltose.(b) What is peptide Linkages? How many peptide bonds are present in a tetra-peptide? (c) Name the hormone which regulates blood sugar level in the body.

Answer»

Solution :(b)The -CONH-bond formed between two `alpha`-AMINO ACIDS. Three peptide BONDS are formed
(C)Insulin or Glucagon.
Discussion
86349.

Answer any FOUR of the following questions. b. What is peptide linkages? How many peptide bonds are present in a tetra-peptide?·

Answer»

SOLUTION :(a)
(B) The peptide linkage (-CONH-) FORMED between two amino acids by the interaction of amino (-NH2) group of one amino acid with carboxylic (-COOH) group of another amino acid with the elimination water molecule.
Three/3
(c )insulin/Glucagon
detailed Answer:
(b) A peptide bond is the chemical bond between two molecules when the carboxyl group of one molecule reacts with the amino group of other molecule, releasing a molecule of water. Peptide linkage is responsible for the primary structure of protein.
Discussion
86350.

(a) Write the Haworth structure of Maltose. (b) (i) Name a naturally occurring amino acid which is optically inactive.(ii) How many peptide bonds are present in a tripeptide?(c) Deficiency of which Vitamin causes Night blindness?

Answer»

Solution :(b) (i) GLYCINE.
(II)DIPEPTIDE contain one PEPTIDE bond and two AMINO acids. Tripeptides contain twopeptide bonds and three amino acids. Tetrapeptides contain three peptide bonds and four amino acids.
(c)Vitamin-A
Discussion