Koya UniversityFaulty of Engineering

School of Chemical & Petroleum EngineeringChemical Engineering department

Laboratory of petroleum and gas properties

EXPERIMENT NUMBER TWOHydrometer

Instructor: Mr. Abdulmajid & miss CheemanAuthor Name: Aree Salah Tahir

Experiment Contacted on: 22/oct/2013Report Submitted on: 29/oct /2013

Group: A

The aim of this experiment:

The objective of this lab is to measure and study density and specific gravity of different liquids by using hydrometer. This gives information how light or heavy a crude oil is.

Theory:

Hydrometer is considered the simplest and the fastest method

in determination of specific gravity of a liquid

The operation of the hydrometer is based on the Archimedes principle that a solid suspended in a fluid will be buoyed up by a force equal to the weight of the fluid displaced. Thus, the lighter the liquid (that is, the less its specific gravity), the deeper the body sinks because a greater amount of liquid is required to equal the body's weight.

A hydrometer is usually made of glass and consists of a cylindrical stem and a bulb weighted with mercury or

lead shot to make it float upright .

The liquid to be tested is emptied into a tall container, often a graduated cylinder.

The hydrometer is gently lowered into the liquid until it floats freely.

The point at which the surface of the liquid touches the stem of the hydrometer is noted

Hydrometers usually contain a scale inside the stem, so that the specific gravity can be read directly .

It is important to know that most hydrometers are calibrated on

15 0C. The actual density can be calculated by

Thermal expansion coefficient of acetone = 0.00143 / 0C

Density of water at 15 0C is 0.999099 g/cm3

EQUIPMENT and COMPONENTS USED

Graduated cylinder: Thermometer:

Hyderometer:

1.Funnel: Tested liquid (Acetone) :

The procedure:1: Fill the cylinder with acetone.

2: Read the temperature of the liquid by the thermometer Tactual . 3: Down the hydrometer into the sample slowly and carefully.

4: Keep the hydrometer floating in center of the cylinder and from the wall.

5: ) After stabilization of the hydrometer, note the point where the surface of the liquid touches the stem.

Calculations:

Tactual=24.4 Treference=15.5 spgr=0.785

T= Tactual- Treference∆ = 24.4-15.5

= 8.9cᵒ

s.p.g.r=ρaceton/ρreference

0.785 = ρaceton/0.999099

ρ aceton=0.784292715 g/cm3

ρ=0.784292715/(1+0.00143*8.9)

ρ=0.77444 g/cm3

Discussion:1: Compare your result (density of acetone)

with any references?

Ans: In the case of using another liquid ,the using of the kind of the hydrometer will change ,if the liquid was heavier than water we will use another different leveled hydrometer from the lighter.

2: Compare your result (density of acetone) with the previous obtained results (Density by bottle method).

Ans: finding density by bottle is less accurate than finding density by hydrometer , it doesn’t mean that hydrometer has a perfect result . it needs a long time to make the hydrometer stand and maybe the distance between the hydrometer and the cylinder

will not be that what we want .