Variation of Conductance in Electrolytes

7/25/2019 Variation of Conductance in Electrolytes

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Variation of Conductance with

Temperature in Electrolytes


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CERTIFICATE

This is to certify that Deen Dayal student of Class XII A, MotherDivine Public School has completed the project titled Variation of

Conductance with Temperature in Electrolytes during the academic

year 2008-2009 to ards partial fulfillment of credit for the Chemistry

practical e!aluation of AI""C# 2009, and su$mitted satisfactory report,

as compiled in the follo ing pages, under my super!ision%

Mrs Janet Garrison

&epartment of Chemistry 'other &i!ine (u$lic "chool


3/15

Acknowledgements

There are times when silence speaks so much more loudly than

words of praise to only as good as belittle a person, whose words

do not e press, but only put a !eneer o!er true feelings, which

are of gratitude at this point of time"#

I would like to e press my sincere gratitude to my chemistry

mentor Mrs Janet Garrison, for her !ital support, guidance and

encouragement $ without which this pro%ect would not ha!e comeforth" I would also like to e press my gratitude to the sta& of the

'epartment of Chemistry at (outh )ark Elementary for their

support during the making of this pro%ect"


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Inde

)% Certificate***************************%% +

2% Ac no ledgements***********************%

+% Aim******************************* .

% Apparatus**************************** /

.% Important Terms************************%%

/% Conducti!ity**************************%% 8

% 1actors Affecting #lectrical Conducti!ity************%% 9

8% (rocedure***************************%% )0

9% (hysical Constants*********************** ))

)0% $ser!ation "et )*********************%% )2

))% 3raph of $ser!ation "et)****************% )+

)2% $ser!ation "et2*********************%% )

)+% 3raph of $ser!ation "et2****************% ).

) %4esult***************************** )/

).%Conclusion**************************%% )

)/%(recautions**************************% )8


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) %5i$liography************************** )9

I6T4 &7CTI 6


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AI'

To find the !ariation of conductance ith temperature in

electrolytes

A((A4AT7"

3lass $ea er, Cu" solution, Cu electrodes, n" solution, n

electrodes, rheostat, $attery eliminator, ater, $urner, thermometer,

flas , ammeter, !oltmeter

T # 4:

; Conductance The property of ease of flo of electric current

through a $ody is called conductance%

; !esistance The o$stacle offered to the flo of electric current is

called resistance%

; Electrolysis The operation in hich electricity causes a chemical

reaction is called electrolysis%

; "hm#s $aw This la states that the current flo ing through a

resistance is directly proportional to the potential difference applied

across it


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V = I x R

% &araday#s $aws

o 1irst =a > The mass of a su$stance produced or consumed inelectrolysis is directly proportional to the ?uantity of charge passing

through it%

m (X Q

or, m = @I @t

here, is electrochemical e?ui!alent I is current t is time in

seconds Q is charge%

o "econd =a > The mass of su$stance produced in electrolysis

directly proportional to its e?ui!alent mass% !" # E" = !$ # E$ = !% #

E%&

o Third =a > The mass of a su$stance produced in electrolysis isdirectly proportional to the num$er of electrons per mole needed to

cause desired change in o@idation state%

Conducti!ity

Bhen !oltage is applied to the electrodes immersed into an electrolyte

solution, ions of electrolyte mo!e, and thus, electric current flo s

through the electrolytic solution% The electrolytic solution and the

metal conductors e@hi$it resistance to the passage of the current $oth

of hich o$ey hm


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The reciprocal of resistance is called electrical conductance% The unit of

electrical conductance is 'iemens (' or ohm-) or mho%

If a solution is placed $et een t o parallel electrodes ha!ing cross

sectional area ) and distance * apart then the resistance is gi!en $y

R = " # C

p called Drho


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; Foltage

; 6ature of electrodes

; "iGe of electrodes

; "eparation $et een the electrodes

; Concentration of the electrolytes

; 6ature of the electrolytes

; 4esistance in the circuit

(4 C#&74#

)% The electrolyte chosen is n" and the electrodes are of n%

2% 4eadings for the measurement of conductance are ta en atinter!als of + &C%

+% (roper precautions are ta en to a!oid e!aporation and to eep

other factors constant%

% The !essel and electrodes are remo!ed and the !essel is cleaned

and filled ith n" solution%

.% The electrodes are refitted in their original place so that the

distance $et een them does not change%


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/% Current is passed and hen the !oltmeter and ammeter sho

steady readings, they are noted%

% The current is s itched off%

)% It is seen that hile the ammeter reading returns at once to

0 position% The !oltmeter needle pauses for a hile at a

particular reading hich is noted do n%

2% This reading indicates the $ac #'1 in the electrolyte%

)% "imilarly, more sets of reading are ta en, and

resistance is calculated%

2% Thus, the !alue of conductance is calculated%

)% The s itched on circuit readings in !oltmeter and

ammeter are ta en%

2% The current through the electrolyte is changed$y adjusting the rheostat and more sets of

readings are ta en%

+% Thus, the mean !alue of resistance is calculated%

)% A$o!e steps are repeated for Cu" as

electrolyte ith electrodes made of Cu%


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5"#4FATI 6 "#T )

1or n'2 3 electrolyte with n electrodes

"

6o

Temperature

4eadingof

Ammeter

4eadingof

Foltmeter

4esistance

Conductance

I V R = V #" C = " # R

) 2+ )00 mA )%0 F )0 H 0%)00 H -)

2 2/ )00 mA 0%9. F 9%. H 0%)0. H -)

+ 29 ))0 mA 0%89 F 8%09 H 0%)20 H -)

+2 ))0 mA 0%8 F %/+ H 0%)+0 H -)

. +. )20 mA 0%80 F /%// H 0%).0 H -)

/ +8 )2. mA 0% . F /%00 H 0%)/0 H -)

) )+0 mA 0% ) F %/ H 0%)80 H -)

8 )+0 mA 0%/. F .%00 H 0%200 H -)

3raph of $ser!ation "et )

inc "ulphate #lectrolyte

0%)

0%0.


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Temperature in degree CelsiusE

5"#4FATI 6 "#T 2

1or Cu'2 3 electrolyte

"

6o

Temper-ature

4eadingofAmmeter

4eading ofFoltmeter

4esistance Conductance

I V R = V #" C = "#R

) 2. C . mA )% F )8%/ H 0%0.+ H -)

2 28 C . mA )%+. F )8%00 H 0%0.. H -)

+ +) C . mA )%+ F ) %++ H 0%0. H -)

+ C . mA )%2. F )/%/ H 0%0/0 H -)

. +/ C 80 mA )%2 F ).%00 H 0%0// H -)

/ +8 C 80 mA )%). F ) %+8 H 0%0/9 H -)

2 C 80 mA )%)0 F )+% . H 0%0 2 H -)

8 C 8. mA )%)0 F )2%9 H 0%0 . H -)

9 C 8. mA )%0. F )2%+. H 0%080 H -)

)0 9 C 90 mA )%)0 F ))%)) H 0%090 H -)

)) .2 C 90 mA )%90 F )0%00 H 0%)00 H -)

3raph of $ser!ation "et 2

o )c

0%0/


13/15

"

T" "

0%02

o "

4#"7=T

The rele!ant graph sho s that the " # Resistance of an electrolyte

increases at a steady rate as the temperature

increases%

C 6C=7"I 6

n heating a solution, it is no n that !iscosity gradually decreases,

ith decrease in !iscosity, the speed and mo!ement of the ions

increases% In other ords, the conductance of the electrolyte increases

ith increases in temperature% ence, the result of the e@periment

agrees ith reasoning%

(recautions

; Fariation of resistance due to one of the factors should $e ept

constant%

; The electrodes used in each case should al ays $e ept parallel to

each other%

0%0


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; The solution should $e ept undistur$ed throughout the

e@periment%

; 1or each o$ser!ation, three readings are ta en and the mean

!alue is considered%


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5I5=I 34A( :

; Chemistry (4art I 5 Text6oo+ for Class XII7 6ational Council of

#ducational 4esearch and Training

; Concepts of 4hysics $ $y C Ferma 5harti 5ha an (u$lishers J

&istri$utorsE

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Variation of Conductance in Electrolytes