1st 2nd law

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FACULTY OF CHEMICAL & NATURAL RESOURCES

ENGINEERING

THERMODYNAMICS & MATERIAL ENGINEERING

LABORATORY

TAJUK UJIKAJI :- First And Second Law Of Thermodynamics

KOD MATAPELAJARAN :- SKF 2711

NAMA PELAJAR

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/KUMPULAN&1 5&( SESI 2&&'52&1& SEMESTER &2

TARIKH UJIKAJI 2nd Fe6rary 2&1& MAKMAL Thermodynamics

NAMA PENSYARAH r. !r8 4ahiyah Ahmad Khairdin

UNTUK KEGUNAAN MAKMAL

TARIKH TERIMACOP MAKMAL

T/T PENERIMA

CACATAN PENERIMA

ULASAN PENSYARAH

PERKARA YANG DINILAI

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CONTENT

+a9e

1. Tit8e 12. Introdction 1

. Theory 2

(. Aarats

). +rocedre

,. 0es8ts (

7. iscssion ,

%. ;onc8sion 7

'. 0eferences 7

1&. Aendi< %

3

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031 TITLE

1st and 2nd Law of Thermodynamics

,31 In+%)u.+'%n

,30 A4STRACT

Thermodynamics can 6e defined as the science of ener9y. ner9y can 6e

=iewed as the a6i8ity to case chan9es. One of the most fndamenta8 8aws of natre is

the conser=ation of ener9y rinci8e. It sim8y stated that drin9 an interaction>

ener9y can chan9e form one form to another 6t the tota8 amont of ener9y remains

constant. That is> ener9y can not 6e created or destroyed. Thermodynamics can he8

s in order to redict whether the wor? can haen or not. There are for 8aws of

thermodynamics> @ero 8aw> 1st 8aw> 2nd 8aw and rd 8aw of thermodynamics. 4t> in this

e<eriment we st in=esti9ate the 1st and 2nd 8aw of thermodynamics.

,3, O4JECTI5ES

1. To investigate the 1st and 2nd Law of Thermodynamics, which are:

• 1st Law: Energy can be neither created nor destroyed during a

process it can on!y change forms.

• 2nd Law: Energy wi!! move from the p!ace that has higherenergy density to the p!ace that has !ower energy density.

2. To show the student of the 1st Law of Thermodynamics and the concept

of the 2nd Law of Thermodynamics.

3. To prove the 1st and 2nd Law of Thermodynamics.

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631 THEORY

The 1st Law of Thermodynamics state that the energy cannot be created

nor be destroyed, but the energy can change form. "n other words, we can

say that the tota! amount of energy remains constant.

General Energy Equation:

ner9y in B ner9y ot

2 - 1 B C - 3

3here>

1 B Initia8 interna8 ener9y of the system.

2 B Fina8 interna8 ener9y of the system.

C B #eat rate.

3 B 3or? done.

For this e<eriment> the ener9y 6a8ance was sed in order to ca8c8ate the heat that

had 6een sed. The ener9y 6a8ance for this system is:

in B ot B ∆system

∆system B &

∆system B ∆hot water D ∆co8d water B &

m;$ T2 E T1*hot water B m;$ T2- T1 *co8d water B &

2nd Law of Thermodynamics can 6e e<ress 6y two statement 6e8ow:

The Kelvin-Planck Statement

It is imossi68e for any de=ice that oerates on a cyc8e to recei=e heat from a sin98ereser=ior and rodce a net amont of wor?.

The Clausius Statement

It is imossi68e to constrct a de=ice that oerate in a cyc8e and rodced no effect other

than the transfer of heat from a 8ower- temeratre 6ody to a hi9her temeratre 6ody.

#rom both statement we can conc!ude that the c!ausius statement is more

accurate or signi$cant to our e%periment. This statement state that the energy

wi!! be more prone to move from the higher density of energy to ther !ower

density of energy without needs to ma&e any wor&. By &nowing the 2nd Law of

2

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Thermodynamics, we can predict whether the process wi!! happen or not by

app!ying the entropy concept.

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731 APPARATUS

'eater, thermometer, stopwatch, big bea&er, sma!! bea&er and e!ectronic

ba!ance.

"31 PROCEDURE

1. 4oth sma88 and 6i9 6ea?er was wei9hed sin9 the e8ectronic 6a8ance.

2. The 6i9 6ea?er was fi88ed with co8d water and the mass of 6oth 6ea?er and water was

9ot 6y wei9hed 6oth of it on the e8ectronic 6a8ance.

. The mass of water was otted down 6y s6statin9 the =a8e of mass for 6ea?er fi88ed

with water with the =a8e of mass for emty 6ea?er.

(. The sma88 6ea?er was a8so fi88ed with water and was heated nti8 the temeratre of

the water reached '&o;. On the same time> the temeratre of the co8d water was

measred.

). The mass of the 6ea?er that contain hot water was immediate8y measred to a=oid

mch heat transfer to the srrondin9s. The mass of the hot water was measred

,. Immediate8y the hot 6ea?er that contain hot water was 8aced in the 6i9 6ea?er that

contain co8d. On the same time> the sowatch was set on.

7. The temeratre for 6oth hot and co8d water was otted down e=ery two mintes nti8

6oth temeratre near8y the same and remain constant.

(

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)

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831 RESULT

830 Ra2 Da+a

ass of hot water : 22'.)9

ass of co8d water : '%'.&9

Time

$ min *

#ot water

Temeratre>

Thot $o; *

;o8d water

Temeratre>

Tco8d $o; *

& %%.& 2'.&

1 7(.& ).&

2 ,,.& 7.&

,1.& 7.&

( )).& %.&

) ).& %.&

, (%.& '.&

7 (%.& '.&

% (7.& '.&

' ().& '.&

1& ((.& '.&

11 (.& '.&

12 (2.& '.&

1 (2.& '.&

1( (2.& '.&

1) (1.& '.&

1, (1.& '.&

17 (1.& '.&

1% (1.& '.&

1' (&.) '.&

2& (&.& '.&

*

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83, Ga*9 % Te*ea+ue !°C$ ;e(u( T'e !'n$

+ ) 1+ 1) 2+ 2)+

1+

2+

3+

(+

)+

*+

,+

-+

+

1++

f/%0 +.+1%3 +.2%2 4 2.2*% 4 31.()

f/%0 +.+2%3 4 +.*%2 .3)% 4 -(.32

Graph of Temperature !e"!#u$% &er$u$ t#me m#'%

hot water

5o!ynomia! /hot water0

co!d water

5o!ynomia! /co!d water0

T#me m#'%

Temperature !e"!#u$%

Ga*9 0: Te*ea+ue 5e(u( T'e

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<31 DISCUSSION

From the 9rah 8otted> there are two trends which can c8ear8y show the theory of

thermodynamics. These theories are inc8din9 6oth the first and second 8aw of

thermodynamics.

The first trend in the 9rah is a ara6o8a cr=e with ne9ati=e 9radient> which can show

that the temeratre of hot water is decreasin9 with time. eanwhi8e> the second trend in

the 9rah is a ara6o8a cr=e with ositi=e 9radient> which shows that the temeratre of

co8d water is increasin9 with time. The chan9es in temeratre for the hot and co8d water

occr nti8 6oth ha=e a8most same temeratre.

This chan9in9 of temeratre can 6e e<8ained 6y the first 8aw of thermodynamics that

the ener9y cannot 6e created or destroyed> 6t on8y can transfer from one form to another.

In this e<eriment> the heat ener9y from hot water is transferred to co8d water and

srrondin9 6t is not destroyed or disaeared. This can 6e ro=ed 6y the fact that the

rise in temeratre of co8d water from 2' =; to ' =; a8tho9h there is no wor? or heatin9 rocess is done on the co8d water. oreo=er> the tota8 of heat 9ain from the co8d

water and the srrondin9 are a8most ea8 to the heat 8ost in hot water.

Frthermore> the second 8aw of thermodynamics which e<8ain the antity and

a8ity of ener9y a8so shown in this e<eriment. It is ro=ed thro9h the heat on8y can 6e

transferred from hi9her temeratre 6ody which is hot water to 8ower temeratre 6ody

which is co8d water and srrondin9. The heat ener9y is imossi68e to transfer from the

co8d water to increase the temeratre of hot water withot any wor? s8ied to the co8d

water system. #ence> this has c8ear8y shown that the direction of heat transfer is on8y

from the hi9her temeratre 6ody to 8ower temeratre 6ody> if there is no wor? done.

4esides that> the rate of temeratre chan9e for 6oth hot and co8d water is decreasin9

with time. In other words> the heat transfer rocess occrs 6etween the hot and co8d water

is faster at the 6e9innin9 of the e<eriment and 9ettin9 s8ower with time. The difference

of co8d water and hot water are a8most @ero at the end of the e<eriment. In order to

e<8ain it> we can say that the rate of heat ener9y transferrin9 6etween the systems and

srrondin9 is direct8y roortiona8 to the difference of temeratre 6etween the systems

and srrondin9.

From the ener9y ana8ysis ca8c8ated> the heat ener9y of amont (,.1&?/ transferred

from hot water to co8d water and srrondin9. #owe=er> there are on8y (1.(22?/ of heatener9y was transfer to water> and it means the heat ener9y 8osin9 to the en=ironment is in

amont of (.7&%?/.

Since the difference 6etween the chan9e of ener9y of co8d and hot water is not ea8 to

@ero> which is not the same as stated in theory> hence there ha=e some errors occr drin9

the e<eriment. The errors that occrred are inc8din9:

1. The ara88a< error may occr when readin9 the temeratre from thermometer.

This error wi88 case the readin9s are not accrate.

2. Second8y> the error may occr when not a88 the heat is transferred to the co8d water.

It is ossi68e for the heat to transfer to other 8ower-temeratre 6ody sch as the

srrondin9> the containers and the ta68e srface. The heat ener9y wi88 8ose to thesrrondin9 faster as a res8t of stirrin9 the water.

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. The de=iation from the rea8 =a8e in theory is 6ecase of there are winds or f8ows

of air from the fan. The f8ow of air wi88 e=enta88y case the rate of heat 8ost to

srrondin9 increases. #ence> it wi88 ct down the time for the system to achie=e

ei8i6rim of heat transferred.

In order to minimise the errors mentioned a6o=e> there are some recommendations.There are:

1. First8y> the osition of the eyes sho8d 6e ara88e8 with the meniscs of

thermometer when ta?in9 the readin9. 4y doin9 so> the ara88a< error can 6e

a=oided and the res8t wi88 6e more accrate.

2. Second8y> this e<eriment sho8d 6e condcted in room. This is 6ecase there is

no heat transferred from sn8i9ht to the system. rin9 the e<eriment> the fan

sho8d 6e switched off so that the f8owin9 of srrondin9 air is minimised and the

rate of heat 8ost to srrondin9 can 6e redced.

. Third8y> an ins8ated container for co8d water sho8d 6e sed. This is 6ecase the

ins8ated container wi88 redce the heat 8ost to srrondin9 and wi88 not affect the

res8t of the e<eriment.(. 4esides> the thermometer sho8d not contact with the wa88 of the containers when

ta?in9 readin9s. This is 6ecase the temeratre of the wa88 is different with the

water since it has different heat caacity. The temeratre wi88 rise if

thermometer 9ets contact with the container which contains hot water and cases

the readin9s 6ecome not accrate.

). Last8y> the temeratre of the hot water sho8d 6e 8ower than the 6oi8in9 oint> so

that the mass of water 8oss de to =aorisation can 6e redced to minimm.

>31 CONCLUSION

As a conc8sion> the e<eriment condcted was fo88owin9 the first and second 8aw of

thermodynamics. =en there ha=e deri=ation from acta8 =a8e and e<eriment res8t de

to some errors> 6t it o6eys the second 8aw of thermodynamics. The heat is transferred

from the hi9her-temeratre 6ody $hot water* to 8ower-temeratre 6ody $co8d water*.

The 6oth system a8so achie=e ei8i6rim when the temeratre of co8d and hot water are

a8most the same at the end of e<eriment.

?31 RE@ERENCE

i. 3y8en ".G. Sonnta9 0> and 4or9na??e ;.>Fndamenta8s of Thermodynamics ,th

ed.>/ohn 3i8ey>!ew Yor?.

ii. htt:55www.??mwe6.?m.my5?imia5s?imia5STKK 111.

iii. 3YL! ".G> SOO!TA" 0> and 4O0"!AKK ;.> Fndamenta8 of

Thermodynamic> /ohn 3i8ey> !ew Yor?

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0131 APPENDI

$1* The chan9e in temeratre for hot water:

T2 B (&.& D 27.1) K B 1.1) K

T1 B %%.&D 27.1) K B ,1.1) K

HT B T2 - T1

B $1.1) E ,1.1)* K

B E (%.& K

$2* The chan9e in temeratre for co8d water:

T2 B '.& D 27.1) K B 12.1) K

T1 B 2'.& D 27.1) K B &2.1) K

HT B T2 E T1

B $12.1) E &2.1)* K

B 1&.& K

$* The mass of hot water:

mh B $22'.) 5 1&&&* ?9

B &.22') ?9

$(* The mass of co8d water:

mc B $'%'.& 5 1&&&* ?9

B &.'%' ?9

$)* #eat caacity of water:

; B (.1%7 ?/5?9-K

ner9y chan9es for hot water B mhot; $ T2 E T1 *hot

B &.22') < (.1%7 $ -(% *

B -(,.1&?/

ner9y chan9es for co8d water B mco8d; $ T2 E T1 *co8d

B &.'%' < (.1%7 $ 1& *

B (1.(22 ?/

1+

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$,* "i=en that

∆U system=∆ U hot water+∆ U cold water=0

mh;$ T2 E T1 *hot water D mc;$ T2- T1 *co8d water B &

where> mh: mass of hot water $?9*>

mc: mass of co8d water $?9*>

;: heat caacity of water $?/5?9-K*>

T1 : initia8 temeratre $K*>

T2 : fina8 temeratre $K*

$7* S6stitte the =a8e in the eation

&.22') ?9 < (.1%7 ?/5?9-K < $E (%.& K* D &.'%' ?9 < (.1%7 ?/5?9-K < 1&.& K

B - (.7&% ?/

This res8t is not comati68e with the theory that stated a6o=e> which is ∆ U =¿ & ?/.

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1st 2nd law

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