gate chemical engineering 2002

8/10/2019 GATE Chemical Engineering 2002

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IGATE - 2002 I ol lo

CHEMIC L ENGINEERING

SECT10N-A 7 5 r b

Th i s qu e sti on co nsists of TWE; NTY F IV E subqu<>.stions ( 1- 25 ) of O NE mark ea d 1. For· ead1of th esr su b-<tne s tion s, four poss ible nnsw er.i(A. '8 , C, and D ) ar ·e gi ven , out of which o nlyone is correct n ~ o · eacl1 sub-que .stio .n byd arkening the nppropJiatc bubb le o n theOBJE CT IV E RE S PO NSE SHE ET (ORS )o sing a sort HB pencil .Do noi u se rhe OR S foran y r·ougb wor · You can use. lh e A nsw e r· Bookfor· an y r oug h wo rk.

2.

3.

(Marks: J. " 25 = 25)

In l ~ e complex plaue. U.1e augle be tweenlines I + il fld - 1 + r(wheret = f = F-i ' )is

3 , lt14b 7tl2c. 3 : ~

d. 7t

[07 I

OJhe tn\ 'e t 6 or the r1111trl (I 11 Is

IJ (J 1,5

[2 v~ I, \1 I

I) 0

[-02 0

IIl() - l II

() 0 - () 5

[ ~tJ l]. I ()

H (I 2

[o.s 0 ill. (} 1~ 2) ()

WludJ of the rollom ng cond.llions aresatisfied nt he cmfcal point by the P -V-Tre lation ora rea l Owd

(8°/) N)- - - - l liW V

' '

b. ( iJ'P) > il/) 0, , . , . • f V r

c. ( cJ < u( fl) = llN l r 1'1' r

d. ( fPI ~ > o [ ) > Uf V- ,. I V ,

Which 9[ the folio" iog holds for any ooo·zero v e t o r ~

a. 7 tr : IIb V xo = U

c. 7 (V ><a) = O

d. V{V o)=o

With mcrcasing flow rate . the "· drnulicefficiencv of a cen l-rifllg;ll pumpa monotonically decreasesb. decreases and th en u1creasesc. remams constan td Increases and hen decreases

(>, For llow pas a nat plate, if X IS th(d iStance along the Il late I lbe dJreCilOO ofllow. the boundary layer U tckness Is

proportJonaJ to

7.

8.

a. Ji

c. \

d.~

For turbulent now of on InCOmpressibleIJUJd tiJrough 3 . pipe, the floW fate Q IS

proporllona l to (AP)". where 6 P 1s 1he

pressure drop . llte value of exponen t o. ISa. Ib Hc. < ld. > IFor nn ideal plug flow reactor the n lue oft b ~Peclet nvmber IS

a. ub 0 0

c. Id IU



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ll

13.

14.

15.

The c.'\tcmtof u rcuction isn. different for reactnn ts and producbh. dimeru;ionlessc. dependent on the stoichiometric

coefficientstl all ol'fhe above

An C . ~ < 1 d 1 e n n i creaction ~ ; I r e spine<> tn >nadiabatic reactor . ·11,.,produc t l<::nlptralurt(cboosu U1o cocr<><:t option) - · tbu rooclorreed temperamrc:n i~ nlw•ys equ:tl toh is always SJWier thn·nc. i ~ · ~ l w n y slesH buncl ma) he gre.iler nr les• thnJl~ l c t l \ n nis mi"ed with st·oich iometrieproportion o f CL'C)'gcn 11J1d complete [)combU$I..d. T 1~ numb,.,. of additionalspcl'il'ications required to determi ne Lhe

produc t now rnte •od compru;ition isII )

h. I• . :td. ~

If the bnftle 1 ')11lcingin a shell and tubo:heat excltanser i n c r c a ~ c : s tlt<>n theR e y n )ld ~number oftha s hd J side lluidn. Riarunin l unebaog\..-db. lnctuMes1:. l n e t' Ca s c~ r decrc113"" depending un

numhc:rot'<hil ll p:1$ ell

d. V e c r e : ~ s a <

rhc tol3.1investment inn project . . RH. Illlakh.s and the nnnual prwfit ill Rs. I.S lnkhs.lf Uw projed IUc is to l '' ' · thou Uoe

~ im p l ertsle of rctt u T1un in \ C81mt-Til lM

.., 15•.b. lll"o"- I.SP u

"· 1soq.111c closed loop po les f a ruble saeondnrder sys tem could be

;o l)<>lh real n d p o ~ i t i v e

b. C(lmple i\ conjugnre with p<lslliw reoI

' 'rt,c:. both real and negau.veU one real ~ i l~ i tiv c and the oth.,. rt:lll

u e g ~ t i v e

A l'irst order ~ 1 \l e m•Vitb uult y g•in andtfme con$tant~ i i subjected lu ainuwidnl

2 <II 10input of i-equcmcyen = l 1t , The ' l'lituclcr ltio fonhis s y ~ t e m;,.a. Ib. 0.5

c. 11./2d. 0.25

16. II J , i . fllc "')uivn l"nl dinmcldr of o n()n-•pherieo l particle. Yp its vo lume and s, hs

surfal;(: ~ r e a ,Uten i t ~ s p h e r i ~ i t y• isdefined by• • <n = 6\t d sf . '

h. ¢ , - I'• I d • • P

c. rp d Ps r I ' '•

d. li = Jt • v17. Ammgu Uo fo llowing •izc reduc tion

equipment m he d t c r e o ~ i n gorder of the

avernge p ~ r u cl~ s i•c llruduced by each ofUt<IU.a, J:ow orushotos. Ball miUs. Fluid I J.lcrgy

miTisb. Ball mills , Jaw c n J . < h c n ~ .Pluid energy

mil llc. Fluid "'lef 'Y mill<. J•w : n o ~ h 's . 11•11

millsd . Fluid unergy mills . l3atl mills. Jaw

en hers, From among th e .WUowing.. cl100Sc on_

that L• not "'"oU1 il1 111icproc"'aa, Methanol zynthe,•isb. Cab lytic crackmgc. A m m a n h l - s y n t h e s i ~

d. C h ;i d ~ t i o nof sulphurI?. The common v used soh en1 '

~ u p c n : n t i ~I x l r ~ c t j o nis

a. Meiliyi·.,Uwl-ketone'b. \Vnli:f

c. C••"'"tetr3ehJorided. C.trbon diox]dc

20. ·n,c a\'etl gc bl>ilinil, puint uf aviationturbine fuel i• d s t tn th:. l ot'• · Lubrica ting oilsb. LPGc. D i c .~c l

d. K."'oo<cnc1 I. Th e number of U.:gr- bf frucdom for ; lu

azeotropic mixture gf ethanol ond wolcr lnvapour- liquid equilibrium , i ~

a . 3



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m

bc. 2.1. I)

22. The portioI mohtre n d 1 ~ l p yo f ~~o m p o n e n l

In un ideal bmllr) ga; mixture ofeompOllilitm l. 31 A t o m p e r ~ t l l r e1' anaprc:SsurcP. is • li111ctiOnunly of'~ . Tb. TandPc T. P anti z

d. T >nd z.23. Whicb of the- foUo\\ing •crontlties c.1n b"

most easily used 10 e r i r ys1e am Llblec rnarorsuperhealed Steam·' r r · ~ r )1 - - \ PUi 1)v

h. nf iN>), = QII i \ . ~ ),

u.. (BPi oT)r= (flS IW )1

d. (iW I N , (&SI BPlr

24. n,c ~ i r n e n o i o n l e s ~grour in m:.ss transit.tJwt is q u i v ~ t e n tto P&':utdtlnumher in heattr.1noferiso. 1-lussoll numbo£'b S he rw ood number

.:. St. lunidtnumber

d , S l:nnto n number

25. The Reynoi<L< analogy lor momcnllllll .heat and ma.sa lr:insfer is best l•prlicob lelor,, , Cr:t.<fl;in IOrbuknl 11011

b. C:JSes h1 lamiu;u-Oowc. L i q u i d ~In turhuh:ot O.ow

<1 l.lquids And gases m l ~ mi n ~ fIIOw

t i•• .r 1 < l l •l l P I : : . - • 1

Tbi$ sect ion consists o f 1 'WENT\ Il l \ ' I<: sobquesHons 2 ~ 5 11) of TWO m•rks each. For

l'UCb of tbcse sulHjuestlous, four p u s s i b l ~

a n sweu (A, II, C 11n d D) arc gfven, O)UI o whichonly o n ~i• correct . An•wcr each <ub-qu lnnby darkening t b ~ upproprh oe bubble on t h ~

OBJECTJ\ 'E RESPONSE SHEET (ORS)o•i ng u 'of t Hll p< ncil. Uo no l use l h~ ORS lorany rough work . You run use I o \ n ~ 'r Bookor any ruu gb wurk.

(M urks: 2 x 25 • 50)

2G .

27,

28

>ur toTile c<>cJ:licientof ¢ in the Tavlor series of.COS X b o n l l l 1 s

a. 2b. (I

c. Id - 111m:.: grudey ol' p.>ln• lA . B &. (.',t>l oduction r ~ t ~ s: (2. 24 & 18 batches. l"'rday. resf><lCiiwl_v) ar" produocd inindcpenden l botch produchon lines and~ t o r e c lm sepomle area•. 'J11e 11umber ul'off·•pecilknuou b3tche. in a day is J . 3and 2 for tr:.des A. 0 & C. respccti1 ·ely.'T'he probability of picking an offspecific:. tion b a t ~ hJrom a modomlyc h o ~ t . : ns t o r n g ~llJ C.O is

23u.

216

b. 24216

().19216

d.I ~

21G

The drag coefficienl for • l>acleriummovin g in w•n"" 3 1 I mrnls, will ba of thefollow n ~order ol' ru.1gnitud•(assume sizeo ; ba a tl;n ium bu micron ondJ;:inernotic ·vi.o(lSity Qf w>lt>r to he10"' m2 sJa. UOOO,. 24

c. IL24

d. U44:29. A gas d e n . : < i ~ y= l.5 kg.lm·'. l s c < l s ~ y- =2

10'' kglrn ) llowing Uu ·ough pa.ekcdbed(partic fe size = 0.5 em, p o r o ~ i r y= 0.5) ~ ~oSllperficial ve locrty of 2 "' "' cau$es apressure drop of 8400 l'a m . The pressuredrop for Dito1hcr g o : ~ .with dcmi ty or Ukgnn ' nnd v ioc<>s ity ,,r 3 H' ltg1n1 •·no w ing ~ ~3 l ~ willl>e~ 840 \ Pahnb. 189()0Palmc. 1261 0 P l n1

d. 1 6 ~ l' n lm~ 0 A pulse tracer· ls introduced in ; In ido:al

CSTR twith a meau residence time t l a ltime 0. The Lim tnkco for the a:cil



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concen lrntion of the ln)ect to reach Ito F ofil5 inll iul 1•a luew iU hen, 2 th. 0 5 ~

- , I(UI9:1cl. 0.693t

3 1. A h • t ~ ba d i a b a l i~ reuctor ut an ini tialtemperate of 3 731:: is filling tilled for ,her.:ncticm A . a, ~ U I T I~ the ht:3t lrl'dletioo l< ·1 IIJ mo lul n3 Kand t h~ h t ~ t

: >p ~ it ) of bo th , \ and D to be .:on.>Cinttmd ettual to SO JnnOI K. T h ~ tempemlttrcrlse atler • ~ on v e r s i on qf 0 ,5 will be

"· s•cb. tO C1 . 20 ('

d. l l)09 (

32. Sle.1111 undergoes T s en t r o pi ~ explnsio n in ~

turbiu ., fronl :soookPu and 40o•c (o:ulrop:)l6.65 kJ/kg K.) lo 15 1 kPo (antmpy of

s>turni ed liqnid = 1.4336 U lkg f.:. entropyf l snturate<l ~ t p u u r= 1 '2234 kJI q: K).n t~ oxJtCMdjtioo of steam i•a. sup< rh :aled v apourb . paltially 1.\ondcnse<l vupouc· 1\<ith

-qu. lity of0,9

e s:durated va po ur

d. pnrli;tJly co ndcn • d vnponr wrthqunhty of 0. I

:n ..cco rding lo Ihe Pen• kc: eq uati on, whotwill be lhe mini mum numbor qf plnlc l,..;qu irod in u d i~ li l l a Ho n i olumn tot epnrate ~ ~ ~ equirnolar binary mi.'lture ofetlrnplln tlnis A & B miJ •in overhcodl'raetion commiulnJ 99 m o l ~ il \ ~ n dnhonom• fulctio n coutn[ning 98 mole · ~ B?1.\ss.tmtc that the re lative V<>latility ~ t l~

2) does not change appreciabl y in the.co lunutlu. 5

b. 9e. l2d. 28

34. A 10 CJn diam e>tor s tea m pipe. c.ur) •ing:.toom at l 80°C. IS cov...-od wi U oninsulati on (condu ctivity = 0 6 Wln'C ) . Itloses heal Ito the s urrou111ing$ at 30"CAnum e • heal lrnn>fer oocffici" ul of 8.0•, m· • for beat Lransfor fro m •urf.ll:i l totho ~ u m J u n d l ng o N ~ gl e c t wall re:;is t;rnce.,rUu>pipe nnol lilm ltl isUlnce or t ~ o m II'

,J u l Illn.e n.s:ul•t iOn dticknes l - j$ 2 em . o.emtc ofheat I ® from Utis m . ~ u l ~ t e t ipipe will ~ e·

~ grea ter th•n that of the 11n-insnl11teds t ~a n tp i p ~

b. less Utan Ua uf the un-insuwled stea mpipe

c . eqUltl to thfil t1f the un-in,u lutcd • tea m

piped leSll than the s t-"' ' piJ>o wi lh e m

insu.latioo3S. lilOII kg or iquid at 3d C I l l well-s trrred

vo;ssd has to oo h e .1 te ~ to 120' C'. usill linuu orscd coili c.lffY irtS c.oudcu- ling s t ~ am

at I5t)•c. 1'he nreo o f he <lea rn co ils Is ).2rn1 .and over.t ll heal transf er OXlelli clen t tot h~ ~ u t i1 1500 \\ l rm 1 •c . . isuntingnugligib lc heat OS$ to s urroundi ng •ndspecific heat capncit y of the liquid to be ~

ldlkg °C. tlto: t i u r~ tak-en for lllil l i 4 u i ~turoadt dcs ir'Cd tc rup<-rnturc will boa. LS mir1b. mut

I . 44 _mind. S1 mit1

36. Fr'Csh ornogc Jllrce couu.it,. 1 2 ~ . (byweight) 5(11ids • nd the rc:8t water . 1) )0 ,. ofthe frt s h j u ice rs s nr Ill a n ev •p ornrf•r toremove "" l:r and ~" " - " ' t ue ~ t ly ntixc:dwith Ute rtnramiog 10 • of fresh j u i~ o .

The l'e' UIUUttproductc on a i ~40 % F<>lids.Th• kS of water rtn1cNCd t'mm I ~ S freshj uice isa. OAb. 0.5c. O.(i

d. 0.7

37. 1 of • <nluratcd aqueous ~ ol u t i n oof •highly so luble ~ om p o n e n tA ~ • 60"C "cooled to 23 °C 'he so lubility limits of Aan: (0 .0 kg A)ltkg water) at60 •C and (0.2k,g A) l(kg water ) at 25•C. 1'hc amounL ink ~ o l1e crystrus lo mt ed ll1

Jr. ll.4b. (),25c. 0 2d. 1).175

38. In the hydrod oalkylution of toluone tobenzene , rhe ti>llow ln reaolions occ ur

t .f / 0 If,_.. f'•t/ 4 - ' I f ,

2Cr.ff 0 . P C,lftu 1 f f ,



w w w .

e x a m

r a c e . c o

m9

40.

41.

Toluene >nd h)'drog..'l\ ttre fed to a reac tor1n n molar rntio : ~ 80 ''• of the 10luenegets converted and the select ivity o

hcozcoc: (dcfjrl od n l e ~ or benzenefonn ed moles of l n lu e n ~ ;converted) jKQ{)l'o- ~ li·aetil)nal C\Jn''=ion r1fhydrogen ~

a.O J(Ib. (},J44

c. t).152d . 0 , .JG

f w. amount R is prud at the end { ' · e r ~

yc tar for n YC J then Lhc nut p resent v slu cof the ann ui ty a t an ioter m ra te Qf I is

a, R(l-J: - 1j

b lf · · ~ I]1(1+1)'

e. R{l+I J'

d .( l • I)'

A co mp:111Y has • depreciab l e im'llslmentof IU 36300 ' ' hk h is <q>recwted in e q u ~ l

l l i s t a U J U C nl ~ in two yea"'- As sume tl10l tltot;.x rotc is 50 % and jntcrosl rate is H) .l' he not pr<lSeul value of tax tlt11l the

contplllly would bave saved. ifi l

boddepn. d atcd 2/3 of tire invcs tmanl in l b ~

unu yc:tr •nd Ihe res t in the soco nd year . i<.. )

b. ;uoc. 375c1 500n u~ J :cc:Juency re<pQnsc ot' n fi r5l otdCTsy$h:m, has a rha<e shil1 11itb loll a- nndUppcc b ou n < ~~ h·e n by

~ [ '-;1~. I ;.;J, [ ·oJ

d. [o;]/\ y l l n d n < nl r u r c :v ~ s S l l l fVo l u r nc 611

m1 hllS I() be d t ~ > i g n e dhi witltstoucl u

-13.

- ~ ~

5

16,

s ol 111

maximum internoJ pre•s ure <if tO atm. Theallowable ileslgn s h t$S c>f the mnterlol is125 N/nim: Dnd currogirm a iiiiW.lfi1Cc i~ 2nun . Ute tbickJtt $ o f the ' C s ~ c lfor •l e n g t h d i ~ n t ct e r ratio or3 will be elu•e t<la ,

'" 6 mmc. Smmd. 1(1 mmA composite wall co nsr•l• of two plates Aand B placed m sorios. nvrrnnl to the nrll\of t tC3L Tb.c tltenn11l <>ottduetivities ore k A

and ko nnd Uo • 1•ccifi< heal capa ci ties 'Cl'l- ond C ro, for platell A o n ~ l:lrespectively P l ~ t eB Ill $ twice l b~

thickn ess <>flllato 1\. At ~ t c .1 dy l13te. Ulctempcrotw ' d i f t c r c n~ o across plato A isgre-• ter tlmn that ocra<s ploh: B when

u. c ..~ c ; •

t.. c < r ~

c. k o.s .d. k >2k h takes 6 hours to dl) ' • wet so lid from5 0 ~ moistun: co ntent to the criticolmois tu re corotenl of 15 •,, liow mocbl o n g ~ rwillli ta k <> to dry th" •olid to 10°omoisture co nl<:nl, under tho srune dry ingcondltiorn; (the equilibrium moishtre

content oJ' be solid is 5"o.lp 15 minh Sl m111c. 71mind. 94-minWhol is the critica l roL>tionoJ sp.;ed. inrovolutiom. p< 1'~ e c on d , fot a buD mill of1.2 in dfametet chat11ed with 70 mmdiometet bJII<. , 0.5h. I,U

c. 2.76d. 0.116A. s on ~ mil<lun:: \1'3$ Rt ned through ostAndard 1 0 - ~ . l t ~ t ' T C . : n l l te u . ~ <

lr t t ~t io n of tltc ownsize mnll.ml In feed.cJvert)ow and imdertl oll wen: i<ruml to be0.38. 0 19 nnd U21, rt-stxc:t:ivcly. Tho81:\ Clcn c l ' t i : : c t i V c n e s ~b • • ~ d011 the OVCl15iZeis• . 0.50b. 1),5g



w w w .

e x a m

r a c e . c o

m

a. 0.68d. 0.62

47 A ngid v e ~ s c l .contslning three m oles ofnitrogen gas nt 30 C. is heated to 2s.o•cAss1nne tlte a-.:,mge heal capacities ofnilr<lge l tn be c; = 2 U J/mo J•C and C . =

20.8 firnol •c. 11te teat required,

neglecting ll1eheat capacity of fueve;;sel ,is~ . 13728l

b. 19206 J

"· 5 76 Jd. 17712J

48. I m oranideaigasat500K rutd IOOOkPaexpan ds revers ibl,y to 5 times i ls i1 ifialvohuue in an msulal.ed container . l f ·the~ p e c l f i <heal. capacl,tr a t t\Jnshnttpn:ssure) of1he ga• is 21 Jimol K.the 6naJ.

runpcrature willbea. 35 I tb. l74Ka. 274 Kd. 15-1K

49. ln the mrumfuctureof suJphurioncid fremelemental s ulplmr. the followmgse<J)Ienceof major opera tions is followed.L Jiu:uace4-c ot tvertet-> absorber

b . urnace-. eVltponttor-> absorber~ .furnace-> convenet:4 evaporatord. converter-'> fumace > absmber

'50. ~ d e r the pr6ductimt af aillluonis frommeU.'lll.e and air <t-• -raw materiul$. 'l'hecatalysts u.•ed ll'e a ) · - for steam;etoiiDing of meOunte and b ) - farammo nia syntlwsisa ( a ) N i/ A I ; . O~ (h )G tt · Z n O/ A I~o ,

b. (a) Fe i z 3 (b) Cu-ZHO/Al203c. (a)Ni iAJ,O, (b) f"e/AI;0 3d. (a) FeJAhO; (b} N'JAI203

FIVIi I W I QUEST1 N8 51-70)

T his se c tion co n$iSls or 1 ' .~ ' J 'Y qu est i o n> o rFlVE mark s each. AN"Y F IFTEEN ou l of lb e seq uesti ons ba\'e to be a nswered o n Ute A usworBook pr ovided.

Ma rk ~ :S 1 5 = 7S)

6of J()5 I. s.,d inm ~ y d r o x : i d eis prodllced in all

~ l e c t r o l ) : 1 i cce l l by the electrolysis ofbrine.a Write tl1e reacli.ans nt the anode,

.:athode and he overall reacfiCIJism aMercury Cell and a DiaphragmCell

b. Mercozy cells produee more

oCillcentrated N.aOHsolution oomparedto .membrane cclls. However ,membrane cells are \l idely replaci ngthe tnerdllry celli itt. the ch loralkaliil (hJSt:ry. Give two m ~ o tmasons fortbis trend.

c. Define t:lte dc-"'mposinoJt dli.cienoy ofan electrolytk call 11Sed for woduci''NaO.H

d. l 1.158 " 10' Coulombs is llSed todefX •i I l gmm equivulenl of NaOH,wltal is u.e Cll Tt\111 eOlciency o f Uecell7

:52. Reduce he follqwins di.il'ereJttial equati<mIo line;lr IQrm

~ r : t = . z tdl

a . Find a general solution lo dtel.it1eartsed eq ua6o n.

b. De leoninc 6te intell:rnlie>ttcon..<>tants1f2 0)=0 . ~

,53 l\•1atnx A = 0.& 0 0 .4 bas the[

0.1 0.5 0

l0.1 5 0.6property thai i t a t i ~ f i e sAx = x, for illlY"ector x.a. Write U1e chamctecistic equation to be

~ < : ~ l v e Jfor eigenvalue.-; ifA"b. Based on visual.observa tion. tiT\d one

of l he elgem•alues of 11..c. F-ind tlte other-twoeigenvaluesof A.

- C'on iile:r tlte mv fn a l iq_rid film of

constant thickness (5) along,a vertical 1Vllllas s1t0Wll.ln t h ~Jigurc bolow.

r ·

I



w w w .

e x a m

r a c e . c o

m

1\s,uming lnmfnM, one-dimens ionul, full)de>•eloped ll<m. lhe j -direction NavlerS t o k e ~ctjUoliun re luoes tu

lvJ t - - j -~ p g: O

~ L t

(\t hen: \'y is the velocity in r dir<:etiun. l.l•the viscosity and p is th e density of thelhtUi(l.)• · St·ate the o o n n d ~ r ycnnditinn* to be

used for Ut" 4<lution Ill vcf(ltit)11o rrtd7

b. So lvtof6r lhc velocity protiJ ..u, If Q i ~ the \'<llumetrie flow rntc t••r unit

wid th nr the Wllll, how VI iJ re)•tecl tnthe lilm thickness 1),

5.5. l'he power re<tn tred In $tir wnter (den.sity=10 )1) kglm ' , viscQ tt) ' O.OOI I;,g/m s) in<>

laboratory e : ~ :p . ,1 m en l witll t11e l m p ~ l l e r

( J h tm ~ le r = S Qln, blRde width = f em)nJ tQtmg ot ~ rpm os 10'2 \V Cons1dc:r onindu. llri•l lilirred '\<Sse whc N ~ lluid(dens ity - 900 k J 'm~ , VINCOSity - 0, J.84l<J Im ~ ) h ~s 10 be stirrc<i3 1 rpm tlllil> "nillOI)ellt:r OJ" 1.6 IU di3mclCr 311d 0.3'2 I I

b l ~ d ewidlh.a. S h<>w tloot the lllbvrntuo) e xp c ~inoeut

und indus(rio l VC'iMel ;ere g < l < m c t r i c o U ~

:ond dyn:omi"'olly i m i l ~ r

b, Estimate tile rower requiromenlJ of hi

industrial vesse LS6 Aio lluws through • snwoth tube , 2.5 emdiameter :utd 10 111 lung. at 37"C. I f thupressure drop lhmug:b tbe tnbe is L(IOUOP;, estima te"· lhe air v el~ it ) through lho I U ~c ana

the l ' r i ~ 1 o o n13ctorb. the: beot t.rntO Ibo c o ~ J l l c i e nt u s i n~ t

(' u lbtom ,\n;log) l a = (Si)(Pr) . 'l·wb"re St i> U1c Stanton Nuntbe.•and r

is thu PrruodiJNumber.Ga• COWitllllL R 8206 con' nllllftno l K

. . r r o,1s4 0 1'""'Y oncllon actor. ~ Re"" t l o r

;c levonl p rope n i<:s or air t md ~ llle gll'encunditoons: voscosity ~ 1 . ~" 10-5 ki fm s.densit y = l l 34 kgim1

• ~pe c i n t ' ' 'c• pacity . C l. - .1.04j) kJ/kg •c. UocnunlCCinductivity = O . t l 2~ W/m • ( '

57 A double pipe aounl.enlurrent heate:tchnnget is designed to oool .;soo k:i\lbrof bt.'tlLune llo\\>lng in the innur pipe fiom

7 ol 10so•c 10 3S C Wuter enter; ~ I 2tJ•C ande ~ i l "at 37"r' In tht annular spnce. Thei n~ i l lc pipe It o ~no inot"' di:omcterof3 .5 emand wall U t i c k uc ~ s11 '3.56 nun . 'l loc: uutCI

t>pe h ; o~ inner d i ~ m e t e tof 5.25 em :inti~ inwloled . Nc:slet ting tn<: w"Jt resislllnCC

to heat t . r a n ~ f e r[i·om the itmer pipe. attdass umins tho indh •idunl film heat t r ~ n s f e r

eoeJficient .tilr w.t¢1' io be 6600 w ~m1 " ( '

..:.111 tllnt";~ the indlvidu:tllwal transf<T t'()d}jdtn l

fur b<:o.ltnc flowin&in lho lunor t>it"'·b. tbc owrnll loeat ltittUfcr eoe JTicleut

base d o n in si de dinm ter o f nner pipe~ . the lntol lcngO• rcqu i 'd lor the helot

c h11ng.:rNu= 0.023 tRe) ' '" (Pr) IU

\VIieN Nu is the Noo•eh :-lumber andP o s t ~ l'rand tl Nloruhe.•,

A \ ' c r ; t g ~t>ropcrtitS of benzene : visO(l.•iiY ~

-1 IO"' 1\g/nt ~ . tbormal oonductivily -(1.1•17 \VIm •c, specitic bent copocity -I 80 J / k ~oc,dens ity = sn kglmJ.

:58. The ; ; , ~ c e s sl l lbhs lree e n~ ) r(lrc ~· c l o h e x a n o n c( I) r phe IOI ( l ) givco hy

(u R1 - 2. L'ix.where: " I ;ond Xl nrc the mole frncl'ions elfcompuut:toL I I und 2 in Ute liquid phos.c:.'11le \'apour p n : : •o u r e o ~of comp nnents at

417 K , . ,_ P , ~ 75 2 kP'a ondP ' 1.66 k u

a. Oerh'i: the ex pressions for activityto e ffi e ut s or each co mponcul as afwtction of co mposition.

b V lrify whether the exprcs6ion• dco'ivcdi n (:o) s o t i ~ ~the Gib ho - DuhomC:.)lla 1on

c. Detenninc ~ ~e equilihrown p re s ~ l r e Pnntl ••apour CliUJIOs ilioo for • liquidpill $< compo•ltion s , : 0.8 •nd 4 17 KA'sumo vapour h •~ eto be idealtt•s .

59. Methane ga• is compressed on n steadystate llc1w process from 101 k:Pa and 27"Cto 500 lPa lllld J 6 s .~ c ..\s .'llmc m ctltonc tobe l iD ideal gll. l undor • U co ndiliollli LR ~

S ~ H J mof. K: specific heat c ~p ac ity - .

C , 'R = I. 7 tl,009 T( k ) l andsurroundhog> to b<: o l a ~ on i t : u o l

tcmpl'fatu rc: of 27"C . l f the to Jol entrop ychang" (of the s y st ~ n • :ond ~m r r o o o n d i n, gs )

d w : i n~ Otc pwcess is 4.S Jltnol K. fwd



w w w .

e x a m

r a c e . c o

m

a. The specific cmhal PI and specificenrrop) changes of tllctbane .

b. The net $haft wont done iUld heatcxcbaugcd wit11 tile surroundings , permu le r Ue th u ~

c. Titc t l t e n n o d ~namro e f f i < l l C lt c ~ of thoproces s .

6H The ruass llul< frorr 11 5 em dnuucreruuphlhaJcnc ~ :~ I placed m st.agnanl tur (IIo ~ u• nnd nllnosphone press ure, is I 471oJ moVm1 s Assume Lhevapour pressttreof unphtbale ne to be 11 15ann m 4u•c andnegligib le bulk concontmrion ofn p h ~t a l e n ein ;air. 1 air starts 1 > 1 0 \ l ~ n g

xross we surface or uaplu:balcuc rail at 3att/s b)• "b:ll. fnolor will the tn:L<S transferm t ~ increase. all other C(lnd ltionsrcnuuning the same'/For sphe res: Sh = 2.1;o0.6 Rc)M (Sc)'•Jlll'burl: Sh is the Sbcnl'cod nun1ber nnd Scis ~ 1e Schmidt number . 11ti ' viscdSJlY nn(idariSII)' of air nre 1.8 • 10'5 kg,lm sand1.123 kg/ rn ), n:spoctil •lll) aud tbe gasconst:mt is 82.(/G em3 ntm/mol K'

1\T i\mn,orun is produced b) the foUo1•·ingreac1io11

N - 3H 1 ~ 2NH ;

In a eommercl: l p rocess for ammoniaproduction, th<. f c ~ dtQ an odbbacle r'cactorc o n t a i n ~I lrn19IIS of nitrogen :mdstoiduomctcic amount of 11\'drogmat 71l0K Whlll rs t h ~ llt:Simun] a iiQII•abkconvcrsron 111 the reactor, 1f the adiabaticcempcra[Ure rise across the reactor sbow .dnor -~ i . ' O c dl00 KAssumerhc li:cd and product streams to beideal gas rnaxturcs. 11tc hew. of rea.,tionat700 K for tbd above reacuon is- c . ~l c u l at cd

co be -94 .2 kJ/mol Mean molar heatC3pacick s C ~ )in che range 700 - 800 K.n r ~ll,oJ , O U2.X9·and n .()4(12 ~ )/ m o lJ{ fornilrogen. hydroge n and ammonia ,r<ispcctival) ,

li It ts dosan:d to extmci.acetone li'om n feedCQJltaining acetone nnd wmer, usingchlorofonn as rhe solvcn'" In t\>O crosscun'unt e:dxactlonstageS ISs hown be low

63

Mol I IScMcru 1 ,. SQivl tlt i

'' S:u u I I· l - ·~ ) Q l . t . l i

I ' .s-1'

Assume thnt 11 ntcr and chloroform nrctmrnlsclblc. 11te following dtl ll an; g 1 1 ' ~ n

fqr the process(a) 11ae feed is an cquinmbr rnLxrurcof ncctone nnd w a h lr

(ii) 11ae quantities o ch lorofonn usedan tla.· two s t a g ~ sarv equal

(ua) b mole o i lhu ace one iu thefucd JS cxl.ractcd 11J slag;; 1

iv) 1 1 t ~extrac t and mflm3tc phases< Kiting from cnch S1agc are rncquilibnum , The equilibriumrelation for the distribution of'ucoroncls giveo by

Mnl0 1 m nct:l1'JitO 11 WJncr rich phu eM 'IC . ••fn:11icrtn t 1dcr l ft:b pbllSe

Mole or M W Ql : h kn .v f t ~ n l l l l ~rtuu.cl ~~ I C 'ut .. M c ~ 1 m 1111dt f.lklni i7' ormr i ~ ~l l f ; G

a. lnd rcatc (wit.h Ute help o t the ~ b o v e

diagramJ the componcms •n .ca.cbs11cam.

b Dcrcm tinc the quontit) of ch lorofonnused 111 each stage pc:rme)I of feed.

c, Dclcnnino the tJlolc th>ctlonof acetonein final product stream .

A countercurrent muiHslagc strippcr nsSh()Wll in frgure bc iQW is used ll removeau impur i.ty from a. cream using purusteam 1011 kg/hr of liquid cn:arncontainmg 20 pariS per millions (ppm) b)weigbt of mpunt) is fed to the stripper , It1 desired to r\ duco t b ~concc niJ'aliou ofimpurit y in l h ~crenm ro I ppm. A5sumoOral the li,quid cream does not e v : ~ p o m t

:irld ~ t e m\locs uot c 9u d~ n s c Tiaocqt•ilib rium (d:uiott is y = l l ~. 11 hem )aod s are we ppm ofi ntpur\tyin steam andcream, respccti vcI)

x.,tj ,..



w w w .

e x a m

r a c e . c o

m

65.

a. ludleate s c h em a u c ~l v tul u x-y ploLt i l ~t:qt rilil)ri um llnc an d uper ntinslmofor minimum s te lltl l nw rule

b Detcnnin • the mrni111111110QW roJe t>fsteam rcquir«i

"· If th<>r o t ~nl' •tcarn input to th• stripperIS 15 times ~ J c minimum. d ete r 1 t u 1 1 ~

the ·re<ttJ r.od lulagru t nun\her < [theoreucn l s tag4s.

/1. simple chemical reue11o11 A _. : tS

>dingL'llrri"d Cllll iu two CSTRs O n n ~ l c d

111 seriC>.Tho volume ot' the hr IL reactur is1.5 timell ibul o l' he second reac lor . l'h"tempen uuros of the r.:actors ar.: s udJ th:ollb" rate CQOSinnt I I the lirsl roaator IS 1.5fimes t h ~ < r n t ~ <QI\slllnt lh• secnudretlotor.

CSI'Il 2

"' Is ih" dnta g1vc:n above cunsis lent for ·al i r~ 1order reac tion kl notics-1 Ju>1ily.

b. Is Ihe datu g i v ~ nal:xwc iltlnsist.lnt 1\)nlsecond o rd< r rcaollon killlltics'/ Jusliiy .

An enzy me tmruubilized OIL the surta ce or" p o n · p o r ou~ w l d c u w l y ~ e su smgle

substtnto rcootloo according to he 1irstorddr rule . :qw tron r v e nby.

\ 1 ~ ~ 1

~

Where V,, 1t0d K., nre llte n:<tclionp a r a m c ~ sancl Sis thes ul:lstrnte (reaetum)con•en lrulion d t l h ~surlilce oftha ><>ltd.a. II reaction rate 1s i b r 1 c dby lrqUid

lilm muss tmn•l;,r rcsi>111nco. rind tlto<IWrnll t'Ulo e xp ~ s s i o nf<lt ' enzymecfilnlysisat stead)' .stale lu terms uf V •

K.,, tho: bull; liq uid ~ u b st r o t econce ntmli n SO oud the film Jnassuunsl c r eocffic ic:tnl L

h. If l h~ r cu ~ l u n 1 1 1 1 ~is • l f h ~ fir> i'TUOrC\'cn nt 1hc bulk liquid co nc<ln tmtio n,whnt will be the vol no or thudli.lctivencss l'llctM f'c.r the l'(ollowingvuluc$ c l' Ibe rouction p o r o . m o t o r . ~ :V.,I0 tlll'lltcm' s. K- 2 I J ' mol/I, k. ~

IO- em s.

•l o l l l

66. A moroury thermometer c:ut be usod UJ

measure the body 16n1pcmturo by placingit ei ther in the mouth or in the unnpit ur up-.1tidnL Th o lnlc bods tompcmlurocun be

Ukon to be 1h ~ tempe rJiur<.l i n s ~ th.:>muuth, wltich is usU1lll.11 higher thuu thetomiJerniUre In tho urntplt b)• 0.5 K.A8 Alfll<. Umt the true hod) teulpenlthreut'pa tient is 312 K and Ute thortllll tneter isiniti ally at 300 K Alsu a s s U l l l ~that het b ~ mt r o m o e r b.:haves like 3 U l : S H ' r d ~

sys1on1with u i r o ~con5tant af-10 secondsa, Ob tuin n rcla110u fur the thoOmtomcror

restli nl 1'( 1) us n li111<rto11of time htICTI]lS or its iniuol tompernture T O) ,und body f¢mpermure TB.

, How long should the thermometer beplaced in U1e pnlient' s mouth in orderIO ~ O ~ U Ntbui lhe ~ . m l r in tho

mensun:mcnl is not greater themoos•, .c. Si uco< tho> body lompemt\tre ttl the

nrmpit is less. the measurement mll<lehere t L ~ i ng . the l n uo m ~ w ri$uorrooted by udding 0.5 K H"" longl l loul u tho ~ l e r n l u me t e r be placed Inlho> urmplt rn urdor tn e n ~ u r e thut thetm or HI th currectcd m e u s u r ~ r l l e n lIS

not r e a ~ < : rthan 0.05°. of tba ttue butl) llompomriJJru.

67. Cons ider aSl

'S iem nf two tan ks 1n sene:<asshowtl hei<J•;•:F, _ _ ,

•Ill.:F,

The level l11 ill l 'aJJk II Is rne".lSol'od mulb ~

lo bo e<;lfllrcJUedby nwuipt )ulloa theUo\1 rate Fe [ is given that F ~= 0.005h,nnd F, = Q.00251r: mJ•s. \\ here h is in m.'l'h<>'cross- SectiOnalorcas of'l'a nl, l t md IIare both equal to l m' .u. D ~ t e n n in e t h ~lrJnsfer 1mction C•fthe

p (()Ct SS

b, Comp ute the lime cons tants of thepr<>celiS. I& lhd upen loop P" " ' .. \>Verdun1ped,. undor dumped ur critica llyda mped?

gate chemical engineering 2002

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