LIQUID DENSITY AND VISCOSITY

Report of Physical Chemistry Lab Activity

Arranged to fulfill one of the assignment in Report of Industrial Process given by Ir. Ninik Lintang, MSc

By

Rita Inayah NIM 131424025

Wynne Raphaela NIM 131424027

1- A Chemical Engineering Cleaner Production

STUDY PROGRAM D-IV CHEMICAL ENGINEERING CLEANER PRODUCTION

CHEMICAL ENGINEERING DEPARTEMENT

POLITEKNIK NEGERI BANDUNG

2014

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ABSTRACT

Density and viscosity characteristics or properties of a substance commonly used to identify the

type of substance. Density and viscosity of fluids have been known and used for determining

other characteristic of substance (fluid), such as mass of substance (fluids), and determining flow

rate. This lab activity purposed to compare the value of water, NaCl solution, and aquadest

density between literature and the value based on this lab activity. Based on practicum the value

of water density is 1 gram/cm3, NaCl solution 1,032 gram/cm3, dan aquadest 0,91 gram/cm3. The

value of viscosity water as parameter is 0,008 ρ cgs, NaCl solution 0,0071 ρ cgs, dan aquadest

0,00815 ρ cgs. The conclusion of determine density and viscosity that is the value earned by

experiment approximated by literature.

Keyword : density, viscosity, water, aquadet, NaCl solution.

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I. INTRODUCTION

I.1 Background

we often use some kind fluid for any purposes. Every fluid has it’s own characteristics

respectively. The characteristics which are normally used for determining the type of fluid,

usually used density or viscosity.

The mass of an object (fluid) is a measure mass per unit volume of the objects. higher the

density of an object, also greater the mass per volume. There is a type of fluid that has a

characteristic quantity a little but has a heavy mass. An example is mercury, mercury has a mass

per unit volume (density) 13,6 gram/cm3, compare with water that has mass per unit volume

(density) 1 gram/cm3. Mean each 1 cm3 mercury has a 13,6 gram of mass, meanwhile water has 1

gram of mass. That show the mercury getting viscous than water.

Based on measurements of the viscosity of the fluid resistance of modified either by pressure or

voltage. On the issue of everyday (and only for fluids), the viscosity is the internal friction or

Thickness. Therefore, the water is thin, having a lower viscosity, meanwhile thick mercury has a

higher viscosity. Simply put, the lower the viscosity of a fluid, the greater the fluid movement

from also.

Density and viscosity of the fluid in such a fluid between different underlying authors to specify

and find density and viscosity of the fluid in physical chemistry lab experiments.

1. 2 Purpose of Experiment

After conducting the experiment, students are expected to

Determine the density of a substance in the liquid state.

Determine the viscosity of a liquid

Calculate the viscosity of a liquid-based experiments

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1. 3. Theory

1. 3.1 Density

Fluid density can depend on many factors such as the temperature of the fluid and the

pressure that affects the fluid. But its influence very slightly so that the mass of a fluid is

expressed as constants/fixed numbers. Density (ρ) is a derivative magnitude obtained by

dividing the mass of an object or substance by its volume. Mathematically the formula of

density is:

ρ = mv ............................................................................... (1)

description:

ρ = density (g/cm3)

m = mass of substance (gram)

V a= volume of substance (cm3)

The units of density in ”CGS”[centi-gram-seconds]‘ is : gram per centimeter cubic (g/cm3).

The density units of international standard is kilogram per meter cubic (kg·m-3)

Example the density of pure water is 1 g/cm3 or equal 1000 kg/m3

The function of density is to told the kind of any substance. Each substance has a different

density.

1. 3. 2 Viscosity

A fluid is a substance that can flow which gas or liquid. One of the properties of fluid is

viscosity . The viscosity of the fluid is block the fluid to flow. Sometimes viscosity is called

fluid’s viscous. Viscous fluid flow in a pipe is longer than a less viscous fluid.

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Coefficient value of fluid viscosity is influential with temperature. At high temperature

viscosity value will be decrease. So, fluids will be getting dilute at high temperature. This

table show viscosity value of fluid at various temperature.

Table 1. viscosity value of fluid at various temperature.

Fluids temperature (°C ) Coefficient of viscosity

ŋ(mPa.s)

water

0

20

40

60

1,80

1,00

0,85

0,60

blood 37 4,0

Machinery oil 30 200

Gliserin 0

20

60

10.000

1.410

81

air 20 0.018

An instrument used to measure the viscosity of a fluid is called viscometer. There

is two fundamental principal to measure coefficient value of viscosity. That is

measurement method based on the rate of fluid flow in vertical capillary pipe. The

instruments used in accordance with this method is ostwald viscometer, based on

Poiseuille's law. poiseuille’s law written :

∆P = 8 ɳ Lπr 4 I v ................................................................................ (2)

description :

P = pressure

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ɳ = coefficient of viscosity

L= the length of the capillary pipe that traversed the fluid

I v = volume’s flow rate

Based on Poiseuille's law, Ostwald viscometer can be determined with the fluid viscosity

if h, , α, L, dan V can be measured. poiseuille's equation becomes :

ɳ= π hg α4

8 LVρt ......................................................................... (3)

description :

ρ = density of fluid;

t = the flow of liquid from a to b;

α = radius of pipe capillar;

h = the distance between the small and larges balls.

if viscosity value ( alcohol) =c ρxtx and water’s viscosity = c ρwtw so alcohol’s viscosity ɳ Against

the viscosity of water ɳ w is :

ɳ x=ρ x t x

ρw twx ɳw ...................................... (4)

the coefficient of viscosity of water is determined through interpolation of data from the table at

the suitable temperature. Ostwald’s viscometer used for measuring coefficient of fluid’s viscosity

, mainly dilute fluids. Viscous fluid should not use this instruments because time required need

of viscous fluid to down through capillary pipes longer than dilute fluids.

Beside ostwald’s viscometer, a methods to measure viscosity there also Stokes methods, Stokes

methods is to determine a speed of an spherical object in a fluids and can determine a coefficient

of fluid’s viscosity. When a force’s resultant that is work at the ball are equal nol (0), so the ball

had a constant rate and the equation is :

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ɳ=2 r2 g9 v ( ρ− ρ0 ) ......................................................... ( 5 )

description :

v = rate or speed,

ρ = ball’s density,

ρ0 = fluid’s density

if distance between AB = h, time from A to B is t, diameter is d and mass is m, so equation 6

becomes :

ɳ= ¿3 h [ m

πd−

d2 ρ0

6 ] ............................................................. ( 6)

This viscosimeter experiment device more suitable for determining the coefficient of

viscous fluid viscosity. An example of this is the equipment for measuring the coefficient of

viscosity of glycerol, oil, or oil. Principle of the calculation based on the speed of the fluid,

the ball is in terminal through data in the form of time for certain crossroads.

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II. EXPERIMENT METHODS

2.1 Experiment Methodology

2.2 Tools and Materials

Tabel 2. Experiment’s Tools

Tools Specification Quantity

picnometer 25 ml 2

Glass funnel - 2

Chemical glass 100 ml 2

Ostwald’s

viscometer

- 2

stopwatch - 1

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determine the density of

water taps, NaCl solution, and aquadest.

used methode to calculate the

density is by used

picnometer and viscosity by

used Ostwald's viscometer

calculate the value of density

and viscosity

compare with literature

The suction ball - 1

scale - 1

Spray bottle - 1

Stirrer stick - 1

Tabel 3. Experiment’s Materials

Material Quantity

Aquadest ± 200 ml

Water taps ± 200 ml

Salt (NaCl) ± 5 gram

2. 3 Physical and Chemical Properties of Materials

2.3. 1 Aquades

1. IUPAC Name : Dihydrogen monoxide2. Other name : Hydroxylic acid, Hydrogen Hydroxide3. Molecular formula : H2O4. molar mass                      : 18.01528(33) g mol-1

5. Kinds                               : liquids6. color                               : no color7. Density                             : 1000 kg m-3, liquid (4 °C), 917 kg m-3, solid8. Melting point                         :  0 °C9. boiling point                         : 100 °C10. Viskositas                          : 0,001 Pa at temperature 200C11. Molecular shapes                 : hexagon12. Momen dipole                   : 1,85 D

2.3.2 NaCl

1. Molecular formula : NaCl

2. molar mass : 58,44 g mol-1

3. Kinds : solid

4. color                              : white

5. Density                            : 2,165 gr/ ml

6. Melting point                     :  801 °C

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Check the volume and temperature-

piknometer tool

Clean and dry the appliance piknometer

Weigh the empty weight piknometer and

noting the empty weight

fiill piknometer with liquid filling as many as

25 ml

Weigh piknometer filled with liquids and record

the total weight of

Calculate the difference in weight of contents

and empty weight*Repeat steps for other

fluids (water and salt water faucet )

7. boiling point                         : 1413 °C

8. solubility                        : cool water and hot water, gliserol, ammonia, HCl, slightly

soluble in alcohol (Nirka, 2013)

2.3 Flowsheet

2.4.1 determine the density of fluid

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2.4.2 Determine the Viscosity using Ostwald Methods

2.5 Safety

Wear a lab coat and closed shoes

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Check the volume and temperature-

piknometer tool

Clean and dry the appliance piknometer

Weigh the empty weight piknometer and

noting the empty weight

Piknometer with liquid filling as many as 25 ml

Weigh piknometer filled with liquids and record

the total weight of

Calculate the difference in weight of contents

and empty weight*Repeat steps for other

fluids (water and salt water faucet )

Prepare viskometer

Oswald

Fill viskometer oswald up to the

specified limit

Draws a number of volumes of

liquid with dropper and bulb

Start the stopwatch when the liquid down

until the sign limits

Turn off the stopwatch to mark the next

limit

Recorded the time

Repeat steps 1-6 for salt water and

aquades

Clean the tool used by the specified solvents to avoid damage

Store tools properly to avoid damage (Ngatin, 2012)

III. RESULT AND DISCUSSION3.1 Observational Data

3.1. 1 Determined of Density

1. NaCl solution (1,2 gram NaCl in 25 ml of water)Density = 1,032 g/cm3

2. Water taps (25 ml)Density = 1,003 g/cm3 ̴

3. Aquadest (25 ml)Density = 1,00 g/cm3 ̴

3.1. 2 Determined Fluid’s Viscosity

1. NaCl solution (1,2 gram NaCl in 25 ml of water)

Viscosity = 0, 00815 p

IV. Water taps (25 ml)Viscosity= 0, 0071 p

V. Aquadest (25 ml)Viscosity = 0,008 ρ cgs (parameter)

3.2 Discussion

Based of experiment density of water taps, NaCl solution, and aquadest 1,003 g/cm3,

1,032 g/cm3, dan 1,00 g/cm3. Based on literature density of water is 0,998 g/ cm3 (liquid at 20 oC), density of NaCl solution (sea water) is 1,020 g/ cm3. The value based on experiment and

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literature have not a significant difference. when experiment the condition of operation at 25 oC

and 927 mbar of pressure, it takes a value of experiments slightly different with literature.

Based of experiments the value of viscosity of aquadest is 0,008 ρ cgs (parametre), water taps is

0, 0071 ρ cgs, and NaCl solution ρ cgs. Based on literature the value of water viscosity (sall

kinds of water ) is 0,008 ρ cgs, NaCl solution (sea water) is 0,009 ρ cgs. The value based on

experiment is slightly different with temperature because of operation condition at experiment is

different with literature.

IV. CONCLUSION

Based on experiment the density of NaCl solution, water taps, and aquadest is 1,0032 g/cm3, 1,003 g/cm3, and 1,00 g/cm3.

Based on experiment the viscosity of NaCl solution, water taps, and aquadest is 0,00815 ρ cgs, 0,0071 ρ cgs, dan 0,0080 ρ cgs (parameter).

The viscosity is influenced by several factors such as temperature, pressure, cohesion and momentum transfer rate of molecul.

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APPENDIX

1. Data Processa. Determine of density

substance : Aquadest (25 ml)

a.Piknometer pyrex

Substance : NaCl solution( 1,2 gram of salt in 25 ml water)

a. Piknometer pyrex

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No Activity Weight (grams)

1. Empty weight piknometer 13, 42

2. Weight piknometer of contents

24, 20

3. Net weight of liquids 10, 78

No Activity Weight (gram)1 Empty weight

picnometer13, 42

2 Weight picnometer of contents

24, 58

3 Net weight of liquids 11, 16

substance : Water taps

a. Piknometer pyrex

b. Determined the value of viscosity

DATA PROCESSES

I. Densitya. Piknometer pyrex1. Aquadest

Waquades= 10,78 gr

Wair(parameter) = 10,81 gr

Density ?

Answer :

ρ = waquadeswwater = 10,78

10,81 = 0, 99 g/cm3

2. NaCl solution

Wair garam= 11,56 grWair(parameter) = 10,81 gr

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No Activity weight (gram)1 Empty weight

picnometer13, 42

2 Weight picnometer of contents

24. 23

3 Net weight of liquids 10, 81

No Zat Waktu waktu waktu Rata-rata

1 Air garam 10, 6 s 12,6 s 13, 4 s 12,2 s2 Air keran 10,6 s 10,53 s 10,36s 10,5 s3 aquades 30,3 s 29,5 s 29,1 s 29,6 s

Density ?

Answer : ρ = w NaCl solutionw water = 11,16

10,81 = 1,032 g/cm3

3. Air keran Wair= 10,81 grWaquades(parameter) = 10,78 gr

Density ?

answer : ρ = wairwv = 10,81

10,78 = 1,003 g/cm3̴ = 1 g/cm3 ̴

2 Viiscosity

The viscosity of the material by the method of comparison using water as a reference

that the viscosity of 0.008 ρ cgs. The value of Aquadest doesn't count because it is

used as a reference of 0.008 ρ cgs.

NaCl solution

ρ = 1,032 g/cm3

t= 1‘’ : 24‘’’= 84 sekon

viskositas ?

answer : yg = ya ρgtgρa ta

= 0,008 .1,032. 84

1. 85 = 0,693 / 85 = 0, 00815 p

a. Taps Water

ρ = 1,003 g/cm3

t= 1‘’ : 17‘’’ = 77 sekon

viskositas ?

answer : yaq = ya ρaq taq

ρa ta

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= 0,008 .0,99 . 77

1. 85 = 0,6098 / 85 = 0, 0071 p

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REFERENCES

Ngatin, Agustinus. 2012. Petunjuk praktikum Kimia Fiska program studi TKPB Politeknik

Negeri Bandung. Bandung : Jurusan Teknik Kimia Polban

Nirka, Ardila. 2013. Volume Molal Parsial. http://kimiadisekitarkita.wordpress.com/2013/06/07 /volume-molal-parsial/ (diakses : 20 September 2013 pukul 14.58 WIB)

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