Electro Chemistry Booklet Solution Subjective

8/12/2019 Electro Chemistry Booklet Solution Subjective

1/76

~ t ~ ~ O ~ ~ ~ o b c 3 v J 0 w

rite the half-cell reaction for the following cells:3+, : ~ Y r t c J t O Y t ? ? a ~ T i 3 + , Ti4+ II Fe Fe2+

b) Pb s) I PbS04 s) Iso II Zn2+ n s)Cl@ H g ~ Hg2C12 Icr H+ I H2, Pt s)d) Pt s) I QH2, Q, H+ CI-I AgCI s) ts

~ d oquinone and Q =Quinone

0) A ~ It 3.-t ~ h 4 t t } C o....--- k.2 t

t , ~ ~ 1 i -+ l e ~ ~ --

b . - ~ ~ a ~ - -t rb-- -1 C ~ }

rL.2-f f 2 e - ~ m: V ~ ) 01-)

C ~ J,H} - r ~ Cr ~ v t { C . } ~

__ : J \1 t t ~ e -;;;;: ~ 2 - --- CD..f J ~A C l - 1 2 - ~ ~ ~ i t ~ .q H t ~ ~ ~.L


2/76

Wr e the electrochemical notations forthe following reactionsa) H2 g) Cu2+ -7 Cu s)b) C 2 g) + 2Fe2+ -7 2Fe3+ + 2Cre) Zo s) 2AgCI s) -7 2Ag s) ZnCI2

d) [Fe CNli H2 gl -7 [Fe CNll- H

d


3/76

L()Cr-f'LcJJ'v.> ~ D o . - ~ 1.3 ii)..Answer whether the following reactions will occur spontaneously or not,under standard condition. k:'V .... 1fj) 11 d 3+ 2+?EO 2+/ ) d EO( 3-1: 2+).\ r Y/V}JOq !tnn) WI Fere ucesFe to Fe . Fe Fe = 0.44 Van Fe/Fe =O.77v . \ j I r :.{b) Wil4lefiildilgallate iOIllibe late02(g) tram water irlacidicmedium? EO (Oz,HzO/H+)';"1.22V {Ef ()Yl 0'I'tI J )JYl t :(c) will O2(g)oxidizesgold to Au CN); inpresenceof CN-(aq)andOH- (aq) ? ~ ~ t EO [Au CN); /Au, CN-l=-0.60 Vand EO OJOW, H20)=0.40V. hz

~ ~ ~ M(d) would you usesilver spoon to stir asolution of CuN03h? EO (Ag+/Ag) =0.80 Vand EO (Cu2+ ICu) =0.34V (e) reactionof Pbwith AgN03.EO (Ag+/Ag)=0.80 Vand EO (Pb2+/Pb)= -0.126V

to Fe2+?EO (Fe3+/Fe2+)(f) will Snreduce Fe3+ =0.77Vand E"(Sn2+/Sn)=0.15Vk Z:t

-- ' 2--1 - Ck -t x.e. -sz:E ~ ~ F e 2 T ~ 1 2 ~ l Y kO,Ti- -( - u t r ~ ,= +r .2 IV~ t W;lt ~ ~ ) :'1: L S P q y l N v r J ~ J

-/ L \tv\no-

-r 02

..,...... 1 ~ 2 - : 2

~10

A u ~ ' a

+ 0).- - : E r Y \ ~ L ~ ~ 1 i J

]12-0tEce-H

- - ~

r - . Eo -1J-l>

~


4/76

\'.

v .

~ ~ s n 1 0 6 \

~ ve t 5 7 ~ e ~v


5/76

E3 Fort cell reaction 2C.4 Co 2C.3 o2O is1.89V If P 0 .ce co2 ,co IS - .28V what S the value of Oee4+/Ce3+

Co c;-- -

o-- {e41Ct 1T -

toF 4 t : / b I v


6/76

@Determine the standard reduction potential for the half reactionCI2 + 2el}7 2C\

Given pt2+ + 2CI Pt + C12 O = - 0.15 V

O =1.20 V

o U t / ) ~ -0, Is;- f 2 0 - f ocJ:L U -

~ v


7/76

Wraecell reactionfor the following cell anddeterminest nd rd state emf of the cellO Ag+/Ag) 0 80 V e O Sn2+/Sn = 0.14 V ItSt 1

.r

\


8/76

i1 Given the standard reduction potentials TI+ + : ~ TI, EO =-0.34 V and T13 + e ~ TI+, O =1.2SV. Examine the sponaneity of the reaction, 3TI+ 2TI + TI3+. Also find O for this disproportionation.EeU1-/T ~ - 0 t 34 \I

-10 ?: .t -.-- ' T .q -t \ t o 12 S VEl/Tf -

3-rQ- ~ T e . ~ 5 t \1+ I ~ - T . ~

{ ::::- .SRf --< Ac

::=- ~ o ~ l J..J-d=r I .S j v-I

\I1IDr1 S f J l l ~ 1


9/76

~ Calculate the equilibrium constnant for the reactin Fe cuso4 => Fe 4 Cu at 25C. Given( 3 ) Fe/Fe2+ = 0.44V, EO Cu/Cu2+ =-0.336V.--

obe e1)::c. ~ P c. ~ SRfpz o.33-' -CO 44)~ ~ O i ~ ~

_ , J __0 , o ~ J . ~ r 9 ._Ce..-v - - I/(...e-\;\ . - _ - -a1M- ~ - ) t G-cU.:o-- 0 / ~ .

C) ~ . k1 ~ .z 0 , 1 1 0- J


10/76

~ or a cell Mg(s) I Mg2+(aq) II Ag+(aq) I Ag. Find theoperating the cell. E /M ) _ maximum work that can be obtain d bO Mg2+ g _ -2.37V, EO Ag+/Ag) =0.8 V. e y. .?. iA: ~ M f 2 C-- ~ . )~ ~ Q

~ -2 ~ i - ~ L ~ ~ 1 c ~ ) ~ ~ ~ - \ + l - ~ ~ ~ ~ " -i f\I\ [ rl ~ . ) Q)

l ~ + I O - E 1 ~ Y oO: q - C- '2-"31) :::?" l';l'V

o\ J ~ '=- ~ Y\ F : ~ l f 6 , 1/ g I0


11/76

st;ndard reduction potential at S C for the d .n re uction of water2HH20+ 2e- +H2 +20H- .S -0.8277 volt. Calculate 1GO& the equilib .nurn constant far the reaction2 H30 +OH- at 25C.

pE I -= -0 .'621 )) , :=: L.

N ~ L U 1


12/76

~ 1L Ct ':: - ~ ~ ? u R T ,Q if K..

JS 9 ~ 6 < :::: ::;> 3 0>1 (t;i.?,J' J (2n ~ J

k [ t-. K e.rv-

2 MP ~ l t t ~ l l L 21 t r tY I \ -2


13/76

Q At 25C the value of K fo r the equilibrium Fe3 Ag :> Fe2 Ag is 0.531 mol/litre The standardFe2 ?electrode potential for Ag e :> Ag is 0.799V. What is the standard potential for Fe3 e :>

Afl )~ ~


14/76

\I -.. ~ = = v ~ ~ 1--1\\/1 J- d - ~ ~ tA j ,L.J 1 ,I ~ ~ ~ ) ) ~ , o - L , ,7./) c ~ c ' -~ - - - - - - - . f / n - o ~ 1-b 4;; w f ill .: 0 ..> Y

-Q. 1.- -h normal potential of Zn referred ~ SHE is O 76V and that of Cu is -0.34V at 25C. When e c e ~ s ofZn is )6?to CuS 4 Zn displaces Cu2+ till equi librium is reached. What is the ratio of Zn2+ to Cu2+ ions atequilibrium?

-

~ ~ JC > - ~ ~

~ c- ~ e u : L Y 6 . . - ~ ZY / 2n \4:= + 0- 1Y - l ~ D fr:rG) ~

z ~ d l ~ o ~ ~2

E ~ t l ~ ~ ;:LKo. [ ~ ~ ~ 1

2

- - - - ~ -

-,OS

2 D


15/76

CkecJ Mn4 1V1n 4 ) Mn 2

(a) Determine EO for: MnO -7 Mn2+2MnO4 when the

. I ....tV M ~ { I + ,e MV\0( E,c :::Os-r,Y/l) ')J..; N.Y\02- E0k -=: o? \2 / 1 1J.v ~ @ MV\ ~ - ~ e 1}- Nr?i E ~ ~ I(). 15') 113:::: 10J N Y\ D2- -t' e oE ~ : : rC S I I I) 'i ::::. J(2;-= -J. Jg f Yl,, .2

CD + Q) T r v _ / \ -f 6U ,>-- 4 G l O y . , _ ~ ~ .. 6G~ 6zi ~ \ F F - ~ f { \ / ~ t Yl2-ft-.: t ) ? f ~ 3 o t ~ ; t , ,

I(O sb i) - -'2--('1' )..{,) -+1(O l fS-) +1( IS)

Q)@)o ~ f\'IV\Di +


16/76

6 f\ V/ 1 0 I v ~ D I -re. 1 Y 1 n 2 C / l 4 ? I Y ) : : O ~ ..:. i ::t ~ 2l 2 2 b ti D l- >j \ cr'('i

f= - =:- 2- C2-.2- c. L0 - t ~ ) \ L ~4 t I ~ ~ G t; \ 1 q ~ \ l

-r r' > 0 -- b ef;I-vL. 0 r A


17/76

8 alculatethe EMF of following cells at 2S0 C.i) Fe I FeS04{a =0.1) II CuS04 a =0.01) I Cu EO {Fe2+IFe) =-0.44 Vii) Fe I Fe2+ a =0.3) II Sn2+ a =0.1) I Sn EO CU2+ICu =+0.34 V

,)iii) Pt, H2{2atm I HCI I H2{10 atm , Pt.A k te 2 - + t - 2 . ~ - SJ (c; .1)C . l.-u2-t cU- ~- C)I 0 1-.

EO Sn2+ISn =-0.14 V

.,L ell

. ~ - f t ~ ~ Or?)

eV

-


18/76

rt ~ } { 2 ~ ~ L2- C J~ - I - - L ~ -;;;

Uo( ~ )

( .E == 002. , _ - - - - - - - - - < L - - l .r\ \


19/76

~ ~ What is the electrode potential of Mg2 I Mg electrode at 25C in which the concentration Of Mg2 isl ::> 0.01 M. EO g2 I Mg} = -2.36 V.

q ----- (J- O DC 1_ j \ j lluJ \~ ~

~ ~ l l id V


20/76

IeUI0 . ,. E' 'nd Efa, h. cellSn I 2 1M) /I Pb2 (lO-3 I Pb.M)EO So2+ I So} =-0.14V EO Pb2+ I Pb) _

J -0.13V Whatdo you infer from cell EMF?~ n -, ~ 2 . . - + L e ~ ..:e::::: ( t M

L:L--: Ph +2-e-- - b==- - .(


21/76

e At what concentrationof Cu2+ Ina solution ofCuSO. wfll the electrodepotential bezeroat 25 C?Can theoxidation potential become positive? O Cu I Cu+ = -O.34V.

~ ~ L \ i ~ :2 t ~ COl J S J [ Q l- J

\) -:::: O V / Yl ::tJ ~ O>LJ ~ O O ~ _ ~ ~ ~ ~

./


22/76

@ A zrn electrode Is placed in a 0.1 M solution at 25C. Assuming th t the salt Is 20 dissociated at thisdilution calculate theelectrode potential. O Zn 2 I Zn -0.76V.

[711'21)= 0-2-1 '0; ; z ~

~

- _ o :}, , O-rJ_


23/76

Calculate the EMF of a Daniel cell when the concentration of ZnS04 and CuS04 are 0.001 M and 0.1 MC.7 respectively. The standard potential of the cell is 1.1 V. c \ (42-1 i l CM 'P\ t-A L4

t:ce1\


24/76

Calculate the pH of following solutions.i) Pt,H2 1 HC , E=0.25 V ii) Pt,H2 I H2S 4, E=0.30 V

iJ-_ t b Y \ b ~

0 ~ : : : 0 ~l:I

,i W-i 4 : _a,3D t ? / ~ [1


25/76

-G The EMFof the cell M I M +(O.02 M) II H+ lM) I H2(g)(1 atm), Ptat 2S C isO.81V. Calculate the valency~ e t a l if the standard oxidation of the metal is O.76V.

L :L \--t -- If\ fv\~ t ~ A


26/76

@ EMFof the cell Zn I ZnSO41a O.Z} II ZnSO41aZ} I Zn -0.0088V at ZSc.calculate the valueof aZ. ~ ~ L \ + ~- =:::::: -- l C\ ~ - - t J3

f 1 ~ ; ; ; : ; ; l( "

----------------'

bn i~ L 1 -r:en --::.CA-z 0 J A ~ \ 2.~ = 1 -

,- , ~ ce..t\ :::: . 0 7

Nt..{ 1\0.t =+ ' \ >EC eA,

O D O ~ g

o2-q ~ , - ~ r j


27/76

~ Equinormal solutions of two weak acids, HA pKa 3 and HB pKa 5 are each placed in contact wit hl7 standard hydrogen electrode at 25C. When a cell is constructed by interconnecting them through a saltbridge, find the emf of the cell.

L ~. . r\- .>s H t l ~

-

~ \ J2 t-\i + \12 -19

~ l : : 0 / v ; 1-~ c c l \ D or os

/ce\\ --D ~ l !


28/76

@ In two v ss ls ea


29/76

'


30/76

~ The emf of the cell Ag I Agi I KI O.OSM) II AgN03O.022 M) I Ag is 0.769 V. Calculate the solubility product of Agl.-

~ ~ f HJ t Q 0 2--2.


31/76

Considerthe cell Ag I AgBr s) I Br-I I AgCI s)lcn Ag at 25C. The solubility product constants ofC / AgBr and AgCI are respectively 5 x 10-13 and 1 x 10-1For what ratio of the concentrations ofBr- and CI- ions would the emf of the cell be zero?

--

Lel.t

0-05111E

to-

...

... ,. K).f ~ f r ~ S f a CJ[ PoIJ LCLjr o r ) 'I >Y f ~ '--- ~ 1 0 13

--....C r ~ J )


32/76

alculate the emf ofthe cellPt, H2(1.0atm) I CH3COOH(O.lM) II NH3(aq.O.01M) I H2(1.0 atm), Pt

~ k i f ~ ~ :t.l ~-rA { . 3 ~ ~ +1

'y ~ ~ ~ l f 1 Q , - - f < 2 ~..L.

c \A Le -k 7-)

to ~ d\ I --di' ~ k ,\ ' \ t J ~ - I - , J ~ 1

.... Clr \t ~ Cz-:=- Rw ~ _ K \ . DT< b ~ 0- ,' J -M(

,

\ j + l t t J \ 1 rt - t '-4-,1 ~ ~ (el-) eel l t a . ~


33/76

, / r I 0 -,w

g t q J? i ~

. r i- o. J4

--


34/76

Thecell Pt, H2 latm) I H+(pH =x) II Normalcalomel Electrode hasan EMF of O.67V at 25C. Calculate thepHof the solution. Theoxidationpotential of the calomel electrode on hydrogen scale is -O.28V.

\{ ~ ~ + t \ l ~ H.-\ t2J if l a ~

L- :2-. [H J,

~ R f () ? g v -

NUYlJ-+- 4) , b 1 ::=-. o 2 g


35/76

C \ l c < M ~ : . ~ ~ Voltage of th cell Pt H, l atm) I HO N 10-3M) II A + 0HOCN. Neglect [H+jb . . g .8M I Ag s) is 1.0006 V. Calculate the K for

ecause of oxidation of H2 g). a

Ag+ + e 7Ag s) =0.8 V.

-

(E


36/76

ctZ/155; I DV l

1 _

10 _ 3 J g S x l o ~ ~ ~ t : 8 XILJ Lj


37/76

culate the voltage,E of the cellat 25 C. Mn s) I Mn(OH!l(s) I MFl2

given that Ksp=1.9 x 10-13 for Mn(OH)2(s)+ 111M , OH-(l.OO x 10-4 M) II Cu2+ O.19 M) I Cu s)

O (Mn2+/Mn) = -1.18 Vo .: (U..A"1( u.;) z e \.HfV 'Y) l.--f + < - -

y=- fvlY)\Q}1) L[ JYl J1-./

CLe- S)

E


38/76

The overall formation constant for the reaction of 6 mol of CN- with cobalt(ll) is 1 x 1019. standardL7 eduction potential for the reaction[CO CN)613- +: -7 Co CN)64- is -0.83 V.Calculate the formation constant of [CO CN)613

Given C03 e- -7 C02 ;EO =1.82 V

i...- , 1 + Ie:- ~ ~ f J 1 E ~ - = 0 ot:;;4 k a SI

Ir):::.2Co ? -t 1 te ~ 7 Co 1 \-

b' ; 0 0 _1-0- K3lJO

rk.. == 1 Qj '1-- to '


39/76

The voltageof the cellZn s) I Zn CN)/- 0.450M), CW 2.65 x 10-3M) II Zn2+ 3.84 x 10-4 M) I Zn s)is E=+ 0.099 V. Calculate the constant Kffor Zn2+ + 4CN-1il Zn CN)42-, the on ly Zn2+ + CNcomplexation of importance. - t~ :> VI 2-e

c.r > ? e, )

t'l.--t 2LC f ~

3


40/76

I .f:dl,., LrTYlt ~

l ::. 6 fz x lO -1


41/76

,volt.g o th I IPt H {g 608torr) I HCIO (4.34 x lO-3M) \ I S.C.E. is E=+O.s32V.Calculae the dissociation constant2for HCIO. Given,E{SCE = 0.242.

......0A:. 0 ~ t + ------ - ~ ~ ~

:,r e. , - - o -c sEA - E --.-------..~ 2---.

0

0 ' .S;: 3 -- =.Cct= ~ EPr~ O ~ ~ ~ 2 ~ yc-. . . 1 V 0 051E-A-- -- r ~ f

3kt ~ L ~ Ylu.- -.....,.O.1-q -:- - 2..

n


42/76

u. : ~ ,2- / (Jlllculaleenlropy and enthal hpyc ange n their standard state

d ~ : : v l p . 01 T: : - ~ ~ ) ~ ,6(,J - p

6 Q _ Y\ l \ ~ ) = --2- f. S ~ ~ G 'f- \ '2--i5{b2-/ {ROT

~ : : o 6 H ~ 3 [ L ~ s , ) 6 1 :: -- d ~ ~ . _ g tJ t 3 - ~ t r < 1 ~ \L: \ \ ~ ? I' g oS k . ~


43/76

HoWonga currentof 2Ahasto bep ssed throuh asolutionof ND to coatametal surf e of 80cm 2 withsum thick layer Density of silver = 10 8g/cm

3

~ 7 e : rlT t Ay . ~ } e ~


44/76

currentwas passed thorough an aqueous solution of an unknown salt of pdfor 160 m n 50sec.~ ~ gmof Pd+nwas deposited at cathode. Find n. Atomic wt. of pd = 106.4f t rn t t Y e: et

L/AW _.S2-- ::0 t0 (, 1 t )( ~ O b sro

Y)


45/76

metal s known to orm fluoride M', . When ID of electricitv spassedthrough a molten I t for~ 3 sec 1 95 of metalisdeposited Find the atomic weight of M What will bethe quantityofelectricity required to deposit the same mass ofCu fromCuS04?

~ ~I, qs C rnwt> y. 1 0 3 3b

2 f 4 ~

{StF 6X 1 ~ r a o

l e S : s ~ at lI.Mf ~ ~ 1 2 J ; - t r t ~


46/76

r;;:j;J ml of 0.1 M (uSO. solution Is electrolyzed with a current of 0.965 A for a period of 200 sec. th e~ t i o n s at electrodes are:Cathode: Cu2 2e- rn Cu s)

Assuming nochange in volume during electrolysis, calculate the molarconcentration of Cu2 , H and542- at the end of electrolysis.

fA.: \U. ( ) ~ J Y \ A . \ , f ) lor c ko\

\f _~ 0 ~ 1 _ ~ ~ L

: { 21+ :Le.- 7 ~ 1 _ h-F- '.L3~ ')S-0 ( 0 \

~ ID /IO()D(--- ~, ) -oo

j S 1YU

( Y\ )-, ~ r y r A ~ J v c, ::
http:///reader/full/JY/A./,fhttp:///reader/full/JY/A./,f


47/76

W ewt::. D 0\ 1 tv ]-- >


48/76

@ 0 fal y concentrated solutionof CuSO4 iselectrolyzed usln.O.o1Fof electricltv calculate:a) The weight of resulting solution b) Equivalent of acid or alkali in the solution.

~ ~ ~ f ~ tC)'O\


49/76

Q An electric current is passed through electrolytic cells in series one containing Ag(N0 3)(aq). and otherV H2S04(aq). What volume of 02 measured at 27 C, 1 atm and 750 mm3 Hg pressure would be liberatedfrom H2S04 if

(a) one mole of Ag+ is deposited from AgN03 solution

(b) 8 x 1022 ions of Ag are deposited f rom AON":! solution.gN 61)~ J t

- .

~ ~ 0 _0 + H t ~ ~ ~ ~ ~ ~ 0 - - 1 ~ I tp.rvJ~ O l - ; _1 4y.. / j ( , '=V

t ; J ~ P>2-}(

- 2-2.~ rr 1if ~ I D ...-

~ ' Y - - t ) 1-.1 o J \ j 2 ~-, 66 'OD 0 ~ 1


50/76

~ amalgam is prepared by electrolysis o a solution o Cdel2 using a mercury cathode. How long should acurrecnt of SAbe passedin order to prepare 12 Cd-Hg amalgam on a cathode of 2gm Hg(Cd=112.4).

1 2 ~ G\HerU 7 8 ~ ~ } r

. ~ I ~ { ~ ? 'l-t t{ 9

( 1: 1 [A/.A;J ~ )2 A 12- ::= 112,4 : (s: X b) 2---1 Q StJO


51/76

~ f t e r electrolysis of NaCI solution with iner t electrodes for a certanin period of time. 600 mL of theV solution was left. Which was found to be IN in NaOH. During the sametime 31.75 g of Cuwasdeposited in the copper voltammeter in serieswith the electrolytic cell. Calculatethe percentage yield ofNaOH obtained. ~ x ~ ~ ~--. ~ I ~ J - r oJ Le 7 Hi.

N~ ~ r f 2 1 l-e-- >12 ~ H r

e \ J C C ~ ~ 1 ~ i N , ~ ~ ~ r stY ~ ~ : : : - _ ~ ~ I ~ r ~- ; ~ ruv

~ ( 2 b },S ;>( 6\....2- >< ~


52/76

~ m u a ~ t i l y of el.ect'idty;s being used to liberate lodlne tat anode) and a metal (at C a ; ~ o d e TheV ass of x hb:rated IS 0 54g and the iodine s completely reduced by50 of0 1 M sodium thiosul hateFlnd theequivalentmass ofx, P

\J 1 v o 0At).12- 'f-5)1 4 ~ \

-s ~ } ~ - ~ --QL- ~ r c; 6n O == ~ ~ V \

j -{lrr 1If


53/76

5 0 x O } . Y- -- )770


54/76

~ T h e standard reduction potential values, EO Bi3+IBi) and EO Cu2+ I CuI are 0.226 V and 0.344 VL:Y respectively. A mixture of salts of bismuth and copper at unit concentration each is electro lysedat 25Cto what value can [Cu2 ]be brought down before bismuth starts t deposit, in electrolysis.

O ~ 7 ~ E:- c cd{U ::v 0 . E. (st dJf:,r'

c ~ LluUJ J . U ucu f ? ; J f ~ f t U ~ ~ t A 9 1 I l ~ --t ~ d ~ 1

:::- 0 4 i f Q O ~ ~ t jz: , /, fV


55/76

A current of 2amps is used or 60 min. to electrolyze copper f rom a solution of Cu+ at a potential of 0.337L/VOltS. .

(a) How many coulombs are used(b) How many moles Cuts) are plated out?

-(e) What weight Cuts) in grams is plated out?(d) What power in watts was used?

Ck ~ ~ . . d Y j I j} ; ltt

W ~ , t , ~ -. e rl Y t ~ ~ o ~ ~ Gt0 c t ~ \ e ~ p J

~ f V 3 : t r n ~M J l ~


56/76

+ (aq) to form Ni(s) for 2.00h using a current of 2.50 amp, what massoff you electrolyze a solution of Ni2~ i S (AW =58.69 g/rnol] is produced at the cathode?N l l - f r Nttxfr) . lSr I />+. f - C l A - ~ --

Wt)N; ~ ~ h t ')( ( ~ 'Y-3(;0-0 ) ( L ~ L 1C e zrrn I

,


57/76

~ t t e r y wasused to supplyaconstantcurrentof whatwas elievedto beexactly0 45A asreadon a~ ~ in the external circuit. The cell was based onthe electrolysis ofa copper sulphate solution. Duringthe30 min thatcurrent was allowed to flow atotalof0.3gof copper metal was deposited at thecathode. Determine theextentto which themeterwas inaccurate

J }c tw= t r ~

06 ~ ~ (i. 601'- ( )~ ~ o

~ = f ~ ,- Q 1-9r ru


58/76

CJUk 7 paf;J. ~ 1 0 . ~ ; ) bz u ~ 1NJI/\ J ttl Y 4 J1L.. ~ be ~ v f_ lIt0 I - lO.. A balloon is being filled with hydrogen produced by the electrolysis o an aqueous solution o an acid. How long

will it take to generate enough hydrogen to li t 1.5 kg by using a current o 8.5 A?

\t,OL ~ [ l , : { - , gez~ :t 0 ~ y S -O\? z V p \ ~ p [ ~ -..../Z TV H lSOV7.---. L y

e>>-----=qS7lD


59/76


60/76

e The reslstance of a conductivity cell filled with O.OIN solution of N,el is 210 ohmat18C Calculate the ~ ent conductivity of the solution The cell constant of theconductivity cell is O ~ m l

e lk-)( D\63)2 1 o m rY- OlBB

II. _ l r '-f 1.9 X 10-- 0 n m. 4-' ) \/ r

Ol l1

rJ 419


61/76

--

... t2 a IS e speer ICi .'. )1 he molar conductivity of 0.1 M CH3COOH solution is 4 6 5 cm mol ~ Wh t l th lfl

conductivity and resistivity of the solution?

K thFrt U>d -wmty7M -7 M.,{axl7-

1 '~ rY1~ ~ A ,-( Y h ~ - ryz fc fn-f-?

Ui b I V\ 1

-:7JlE = AJIJJ

- - -. < S em L ro.o,1 r l-k t e o Dro I1/

rJ--7

I


62/76

he conductivity of pure water i onductivity cell with electrodes of cross sectional area 4cm 2 and 2 cm apart is 8 x 10 rn7 S cm lill , g -f 10.- 5 ~ m 1Ii) What is resistance of conductivity cell ?Iii) What current would flow through the cell under an applied potential difference of 1volt

R .... ) ~ ~ ) (0si ohm

.....

....... g )( 0;+ : g -b - 6h J C ,, 8o rY\ mJ D ~ g

I::: L G2 s I b S-....

,=- 1 ~ 6 X 1 0 -b A l


63/76

Resls tlvitv of O 1M K I solution Is 213 ohm em In a conductIvity cell Calculate the cellconstant i its resistance is 330 ohm c>t ll _etJtV 1Nv i

R t ~S ~ ~ l:Ll3 7;-)


64/76

. . . . :

'. Resistance of a O lM KCI solution in a conductance cell is 300 ohm and specific conductance ofO lM KCI is 1.29 x 10- 2 ohm 1 cm- 1. The resistance of O lM NaCI solution in the samecell is 380 ohm. Calculate the equivalent conductance of the O lM NaCI solution.~ .LJ.- ~ ,......,

q z \ ~ g r ~ R ~ e C - ~

- So-o XY-.1


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@ OhM. For 0 01N KCI the resistivity 709 22 Scm Caicuiate the ondu tivity and eqUivalentconductance

\


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iWA--

fo;- oCftk ~ r en']7 o12.1- oIrm fYj /1

It J - ~ O/Itt rYJJ .i

L D D V O ~ o


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( 4hwr 8:P-.:2 ?> .5). A solution containing 2.08 g of anhydrous b ~ c h l o r i d e is 400 CC of water has a specific

conductivity 0.0058 ohm-1cm-1. What are molar and equivalent conductivities of thissolution.

Iv IV\. ;c k )< I {YUO z lO g 1- I Ct( J\: )0 1 ~ O D2'i[ W\ 2-3 L 3 3 c r h m ~ ~ m L r n c ~l

I D 0 2 ~ M '/.. ...\ .

) f


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9.Equivalent conductance of 0.0 N Na,S04 solution is 12.4 ohm- em e q l The equivalentconductance at infinite ilution is 129.9 ohm 1 cm2 What is the degree of dissociation in0.01 N Na2S04 solution?

l ~ L~ ~ y ~ ~ ~ ~ bS L;

f \ M ~ 1 ' \f l j1


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t f ~LY-- Specific conductance of a saturated solution of AgBr is 8:486x10 7 -Speclflc conductance of ohm . em 1 at 25C.6 2pure water at 2SC . @gNO, and KNO rs 0.7S . 0 ohm- cm - .A3 are 137.4 133 131 S cm2 1 m For K r Isolubility of AgBr in gm/litre. mol ) respect ively. Calculate the


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~ t u t e d solution of AgCI at 2S C has specific conductance of 1.12. 0 6 ohm-1 em-I~ ~ A : Ag" and A.:CI are 54.3 and 65.5 ohm 1 cm2 / equi. respectively. Calculate thesolubility product of AgCI at 25 C.

M C'- ~ . /~ f ~

..0GL

.r .< k ~ J J I 0 0 0 ~ rl 1l ' i

5 A.. ~ Ai d . -dC?J .

2-s


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~ ~ Y d f U o r l c acid is we k acid. t 25 C, the mol r conductivity of O.002M HF is\:7;76 2 ohm-1 cm2 mole-1. If its Am = 405.2 ohm ,l cm2 mole-1 calculate its degree of

dissociation and equilibrium constant at the given concentration.

o 0-kl . Ld-) CoZ _

. I C I ~ . 1

Ld. L : ' [[r-c)

~ { ~ ~ 1


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@ e- ' mo respectively. a an CH are 426.1 1265 and 91 S cm2 1-1 .. The value of A% for HCI N CI 3COAIaCalculate the value of A% for acetic acid If the . .at 250 C,calculate its degree of dlssodatl squlvelent conductivi ty of the given acetic acid is 48.15Ion.( 2 vt

J:hi- u u ~ r vi 1 f ~ l ~

...'Il ()13 LDD11pC .J\; \ { ~

J\-0() Nt\cJ z:1\'fJ

V - c r l 10"- -z:l12

I)vL ~ J o D J ~ 1

AoO A ~ f-S(IV u'1;}ll\1 t ;vrJ..

-(j)-0

r- j)

0) ~ j -h)-4.4' I I i i s -t:3J ~ , JO'0Wt2me/'""'


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~ a l c u l a t e the specific of 0.1 of atonductance a M aqueous solution NaCI roomV : e m p e r a t u r e , given that the mobilities of Na and CI- ions at this temperature are

4.26xlO-8and 6.80x10-8 m2 v-1 s-l respectively.

IL tJo.. t .: N fA t ........-S(;K OQ Y I 1- )0 ~ 3 / . ; l t r ~ 6 b M 3

b i r lOr h ~ - . l ~ 1-f'(Y1DV

,s

\ ;. 1 \ r ~ : X t(hJO X . ~ [.067 6 ~ 1 _ h J r


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he strong e l e t r y ~ e s NaOH, a ~ and BaCI2 the mol r ionic conductivities at infinite2~ ~ I u t l o n are 248.1x10 4 126.5 x10 4 and 280.0 x10 4 mho cm mol 1 respectively.

Calculate the molar conductivity of Ba(OH12 at infinite dilution.

(rI f J.. 1-- : -[ c + 2-- D - 2- 3)

- 2- 0 t Z o ~ + 2 i 2 t r ~ J y . . t D ~ _ 2 0 H .I{: l2-g0 t ~ qj 2 - ~ 5 3 . 0 f l e~ 5 ~ 3 2- , I 4 ] _ ~ I

. - C f t l z . ~


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@ 2mol-1At 25 C, . . : IH+I = 3.4982 xlO-2 5 m2 mol 1 and OH-I=\8 x10-2 5 m .Given: Sp. conductance = 5.1 x10 6 S m 1 for H20 determine pH and K w

) ( l ~ l ' g r \00 0S;;S-9

Q:4 1 2--) IO


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If II 1 --L -=- S >I l 6 I ~ - - - - armf j

-0 It H ] j

Electro Chemistry Booklet Solution Subjective

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