Laporan Praktikum KI2241 Energetika Kimia Percobaan N-1 PENENTUAN VOLUM MOLAR PARSIAL
Nama
: Fry Voni Steky
NIM
: 10514034
Kelompok
:4
Tanggal Percobaan
: 17 Februari 2016
Tanggal Pengumpulan
: 24 Maret 2016
Asisten
: Muhammad Reza (20514060)
LABORATORIUM KIMIA FISIK PROGRAM STUDI KIMIA FAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM INSTITUT TEKNOLOGI BANDUNG 2016
Penentuan Volum Molar Parsial
I.
Tujuan Percobaan
1. Menentukan volum molar parsial larutan Natrium Klorida sebagai fungsi rapat massa
II.
Teori Dasar
Variabel termodinamika dapat dibedakan menjadi dua jenis yaitu variabel ekstensif dan variabel intensif. Kedua variabel tersebut secara matematis dapat dinyatakan sebagai fungsi homogen berderajat n. Fungsi ini kemudian didiferensiasi dan menghasilkan persamaan yang dikenal sebagai teorema Euler untuk fungsi homogen berderajat n.
N1
Nj=1 +
N2
Nj=1 +
... =
− f(N , N , ..., N ) 1
2
i
Terdapat tiga sifat termodinamika molar parsial, yakni :
Volum molar parsial dari komponen-komponen dalam larutan
Entalpi molar parsial
Energi bebas molar parsial Sifat-sifat molar parsial di atas dapat ditentukan dengan beberapa metode
diantaranya yaitu metode analitik, metode grafik, metode intersep dan metode molar nyata. Pada percobaan ini akan ditentukan nilai volum molar parsial dari larutan NaCl dan MgCl2 sebagai fungsi konsentrasi melalui pengukuran rapat massa. Demikian, pada percobaan ini akan digunakan piknometer untuk mengetahui nilai rapat massa zat yang kemudian akan dialurkan dengan persamaan matematis menggunakan metode volum molar nyata dan dapat diperoleh nilai volum molar parsial larutan NaCl
∅
dan MgCl2. adalah volum molar nyata suatu zat.
=
+−+ +−
III.
Data Pengamatan
Truang = 26oC [NaCl]induk = 3 M VNacl (mL)
[NaCl] (M)
Wpz (gram)
5
0,3
43,35
10
0,6
43,64
15
0,9
43,95
20
1,2
44,24
25
1,5
44,57
Wpikno kosong = 16,89 gram Wpikno + air = 43,03 gram
IV.
Perhitungan
Diketahui massa jenis air pada suhu 26 oC = 0,99681 g/mL a) Penentuan volume piknometer (Vp) Vpikno
=
b) Penentuan NaCL (
=
+− = ,−, = 26,2237 mL ,
)
+− = ,−, = 1,0090 g/mL ,
[NaCl] (M)
(g/mL)
0,3
1,0090
0,6
1,0201
0,9
1,0319
1,2
1,0429
1,5
1,0555
c) Penentuan mol NaCl (mol) Untuk larutan NaCl dengan konsentrasi 0,3 M
× , ×, =
nz
=
= 0,007867 mol [NaCl] (M)
Mol NaCl (mol)
0,3
0,007867
0,6
0,015734
0,9
0,023601
1,2
0,031468
1,5
0,039336
d) Penentuan massa zat terlarut (Wt) dan massa pelarut (Ws) Untuk larutan NaCl dengan konsentrasi 0,3 M Wt = mol NaCl x Mr NaCl = 0,007867 x 58,44 = 0,4597 gram Ws = Wpz – Wpk – Wt = 43,35 – 16,89 – 0,4597 = 26,0003 gram [NaCl] (M)
Massa zat terlarut (gram)
0,3
0,4597
0,6
0,9195
0,9
1,3792
1,2
1,8390
1,5
2,2988
[NaCl] (M)
Massa pelarut (gram)
0,3
26,0003
0,6
25,8305
0,9
25,6808
1,2
25,5110
1,5
25,3812
e) Penentuan mol pelarut (ns) Untuk larutan NaCl dengan konsentrasi 0,3 M ns =
= , = 1,4429 mol ,
[NaCl] (M)
Mol pelarut (mol)
0,3
1,4429
0,6
1,4334
0,9
1,4251
1,2
1,4157
1,5
1,4085
Φ
f) Penentuan volume molar nyata ( ) Untuk larutan NaCl dengan konsentrasi 0,3 M
Φ = z1 .[ 1 ( . )] 1 .[58,44 1 (43,3543,03)] Φ = 1,0090 0,007867 43.03 .16,89 =57,86326 mL/mol [NaCl] (M)
Volum molar nyata zat (mL/mol)
0,3
57,86326
0,6
57,23621
0,9
56,58142
1,2
55,98532
1,5
55,31610
g) Kurva
Φ terhadap akar mol zat Grafik
58.5 ) Φ 58 ( t a Z 57.5 a t a y 57 N r a 56.5 l o M 56 m u l o 55.5 V 55
y = -23.085x + 60.029 R² = 0.9863
0
0.05
0.1
0.15
0.2
0.25
Akar mol zat (mol)
Dari kurva regresi hasil plot Volum molar nyata zat dan akar mol zat diperoleh persamaan regresi y = -23,085x + 60,029 .Sesuai dengan persamaan y =
√ dan c adalah volum molar nyata (Φ ). Sehingga = 23,085 dan (Φ ) = 60,029. diperoleh nilai √ o
mx + c dimana m adalah
o
h) Penentuan volume molar parsial Volum molar parsial zat (Vz) Untuk larutan NaCl dengan konsentrasi 0,3 M
=Φ 2. (Φ √ ) , = 57,86326mL/mol , 23,085 = 57,8578 mL/mol [NaCl] (M)
Volum molar parsial zat (mL/mol)
0,3
57,8578
0,6
57,2203
0,9
56,5521
1,2
55,9398
1,5
55,2522
Volum molar nyata air (Vr)
= 18,02 / = 18.0777 / = 0.99681 gram/mL Volum molar parsial air (Va) Untuk larutan NaCl dengan konsentrasi 0,3 M
= 2 (Φ ) √ 0.007867 = 18,0777 / 2 1.4429 23,085 = 18.08328 mL/mol
[NaCl] (M)
Volum molar parsial air (mL/mol)
0,3
18,08328
0,6
18,09359
0,9
18,10707
1,2
18,12321
1,5
18,14163
V.
Pembahasan
VI.
Kesimpulan
Didapat volum molar parsial larutan Natrium Klorida sebagai berikut.
VII.
[NaCl] (M)
Volum molar parsial NaCl (mL/mol)
0,3
57,8578
0,6
57,2203
0,9
56,5521
1,2
55,9398
1,5
55,2522
Daftar Pustaka
Atkins, P.W. 1993. Kimia Fisik . Jakarta : Erlangga Levine, Ira N.2009. Physical Chemistry Sixth Edition. New York: Mc Graw-Hill. G,W, Castellan, Physical Chemistry, edisi kedua, Addison Wesley, Massachussets, 1971, hal, 347-350 http://old.iupac.org/goldbook/BT07273.pdf
VIII.
Lampiran
A. CRC (Data Nilai Rapat Massa Air pada Berbagai Temperatur)
STANDARD DENSI TY OF WATER This table gives the density ρ of water in the temperature range from 0°C to 100°C at a pressure of 101325 Pa (one standard atmosphere). From 0°C to 40°C the values are taken from the IUPAC publication in Reference 1 and refer to standard mean ocean water (SMOW), free from dissolved salts and gases. SMOW is a s tandard water sample of high purity and known isotopic composition. Methods of corr ecting for different isotopic compositions are discussed in Reference 1. The remaining values are taken from the NI ST Chemistry WebBook, Reference 2. Note that the IUPAC values refer to the IPTS-68 temperature scale, while the NIST values are based on the ITS90 scale (where the normal boiling point is 99.974°C). The conversion between these scale s can be found in Sec. 1. The difference between the scales leads to a difference in the density of water of about 20 ppm in the neighborhood of 100°C and much less at lower temperatures. References 1. Marsh, K. N., Ed., Recommended Reference Materials for theRealization of Physicochemical Properties, Blackwell Scientific Publications, Oxford, 1987. 2. Lemmon, E.W., McLinden, M.O., and Friend, D.G., “Thermophysical Properties of Fluid Systems” in NIST Chemistry WebBook, NIST Standard Reference Database Number 69, Eds. P.J. Linstrom and W.G. Mallard, June 2005, National Institute of Standards and Technology, Gaithersburg MD, 20899 (http://webbook.nist.gov). 3. Wagner, W., and Pruss, A., “The IAPWS for mulation 1995 for the thermodynamic properties of ordinary water substance for general and scientific use”, J. Phys. Chem. Ref. Data 31, 387-535, 2002. 4. Saul, A., and Wagner, W., “A Fundamental Equation for Water Cov ering the Range From the Melting Line to 1273 K at Pressures up to 25000 MPa”, J. Phys. Chem. Ref. Data 18, 1537-1564, 1989
t /°C
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
0.0 0.9998426 0.9999015 0.9999429 0.9999672 0.9999750 0.9999668 0.9999430 0.9999043 0.9998509 0.9997834 0.9997021 0.9996074 0.9994996 0.9993792 0.9992464 0.9991016 0.9989450 0.9987769 0.9985976 0.9984073 0.9982063 0.9979948 0.9977730 0.9975412 0.9972994 0.9970480 0.9967870 0.9965166 0.9962371 0.9959486 0.9956511
0.1 0.9998493 0.9999065 0.9999461 0.9999687 0.9999748 0.9999651 0.9999398 0.9998996 0.9998448 0.9997759 0.9996932 0.9995972 0.9994882 0.9993665 0.9992325 0.9990864 0.9989287 0.9987595 0.9985790 0.9983877 0.9981856 0.9979731 0.9977503 0.9975174 0.9972747 0.9970223 0.9967604 0.9964891 0.9962087 0.9959192 0.9956209
0.2 0.9998558 0.9999112 0.9999491 0.9999700 0.9999746 0.9999632 0.9999365 0.9998948 0.9998385 0.9997682 0.9996842 0.9995869 0.9994766 0.9993536 0.9992184 0.9990712 0.9989123 0.9987419 0.9985604 0.9983680 0.9981649 0.9979513 0.9977275 0.9974936 0.9972499 0.9969965 0.9967337 0.9964615 0.9961801 0.9958898 0.9955906
0.3 0.9998622 0.9999158 0.9999519 0.9999712 0.9999742 0.9999612 0.9999330 0.9998898 0.9998321 0.9997604 0.9996751 0.9995764 0.9994648 0.9993407 0.9992042 0.9990558 0.9988957 0.9987243 0.9985416 0.9983481 0.9981440 0.9979294 0.9977045 0.9974697 0.9972250 0.9969707 0.9967069 0.9964337 0.9961515 0.9958603 0.9955602
ρ/g cm– 3 0.4 0.5 0.9998683 0.9998743 0.9999202 0.9999244 0.9999546 0.9999571 0.9999722 0.9999731 0.9999736 0.9999728 0.9999591 0.9999568 0.9999293 0.9999255 0.9998847 0.9998794 0.9998256 0.9998189 0.9997525 0.9997444 0.9996658 0.9996564 0.9995658 0.9995551 0.9994530 0.9994410 0.9993276 0.9993143 0.9991899 0.9991755 0.9990403 0.9990247 0.9988791 0.9988623 0.9987065 0.9986886 0.9985228 0.9985038 0.9983282 0.9983081 0.9981230 0.9981019 0.9979073 0.9978852 0.9976815 0.9976584 0.9974456 0.9974215 0.9972000 0.9971749 0.9969447 0.9969186 0.9966800 0.9966530 0.9964059 0.9963780 0.9961228 0.9960940 0.9958306 0.9958009 0.9955297 0.9954991
0.6 0.9998801 0.9999284 0.9999595 0.9999738 0.9999719 0.9999544 0.9999216 0.9998740 0.9998121 0.9997362 0.9996468 0.9995443 0.9994289 0.9993010 0.9991609 0.9990090 0.9988455 0.9986706 0.9984847 0.9982880 0.9980807 0.9978630 0.9976351 0.9973973 0.9971497 0.9968925 0.9966259 0.9963500 0.9960651 0.9957712 0.9954685
0.7 0.9998857 0.9999323 0.9999616 0.9999743 0.9999709 0.9999518 0.9999175 0.9998684 0.9998051 0.9997279 0.9996372 0.9995333 0.9994167 0.9992875 0.9991463 0.9989932 0.9988285 0.9986525 0.9984655 0.9982677 0.9980594 0.9978406 0.9976118 0.9973730 0.9971244 0.9968663 0.9965987 0.9963219 0.9960361 0.9957413 0.9954377
0.8 0.9998912 0.9999360 0.9999636 0.9999747 0.9999696 0.9999490 0.9999132 0.9998627 0.9997980 0.9997194 0.9996274 0.9995222 0.9994043 0.9992740 0.9991315 0.9989772 0.9988114 0.9986343 0.9984462 0.9982474 0.9980380 0.9978182 0.9975883 0.9973485 0.9970990 0.9968399 0.9965714 0.9962938 0.9960070 0.9957113 0.9954069
0.9 0.9998964 0.9999395 0.9999655 0.9999749 0.9999683 0.9999461 0.9999088 0.9998569 0.9997908 0.9997108 0.9996174 0.9995110 0.9993918 0.9992602 0.9991166 0.9989612 0.9987942 0.9986160 0.9984268 0.9982269 0.9980164 0.9977957 0.9975648 0.9973240 0.9970735 0.9968135 0.9965441 0.9962655 0.9959778 0.9956813 0.9953760
