Republic of the Philippines
Central Mindanao University
University Town, Musuan, 8710 Bukidnon
Department of Mechanical Engineering
Mechanical Engineering Laboratory 1
Plate No. 6
Determination of Density, Specific Gravity and Viscosity of Liquid Fuels
Submitted by:
Date Performed:
DE LOS SANTOS, ANDREW JR. A.
NOVEMBER 20, 2021
Schedule:
Date Submitted:
TTh 1:00 – 4:00 PM
NOVEMBER 21, 2021
I.
Objectives

To learn what Liquid fuel is and its classifications.

To learn what Density, Specific Gravity and Viscosity of Liquid Fuels are.

To identify the instruments used to measure the Density, Specific Gravity and
Viscosity of Liquid Fuels.
II.
Discussion
LIQUID FUEL
Liquid fuels are those combustible or energy-generating molecules that can be
harnessed to create mechanical energy. Most liquid fuels, in widespread use, are or
derived from fossil fuels such as gasoline, diesel, kerosene, alcohols, and hydrogen.
Liquid fuels have lower ash contents and are easier to upgrade, because it removes
unwanted impurities such as nitrogen and sulfur. Liquid fuel can be burned in pools or
sprays and vaporizes in two modes.
TYPES OF LIQUID FUELS
PETROLEUM
Petroleum is a naturally occurring
liquid found beneath the earth’s surface
that can be refined into fuel. Petroleum is
used as fuel to power vehicles, heating
units, and machines, as well as it can be
converted
into
plastics
and
other
materials. It’s been created by the
decomposition of organic matter over
millions of years. Petroleum is formed
when large quantities of dead organisms,
primarily
underneath
zooplankton
sedimentary
and
rock
algae,
are
subjected to intense heat and pressure.
COAL TAR
Coal tar is a complex mixture of
hydrocarbons produced by the pyrolysis of
coal. It is a dark viscous liquid primarily used
in the manufacture of other chemicals. Coal
tar constituents may be absorbed via
inhalation, ingestion, or dermal contact. Coal
tar is derived from coal. It is a byproduct of
the production of coke, a solid fuel that
contains mostly carbon, and coal gas.
SHALE OIL
Shale oil is the product of the thermal
reaction and decomposition of kerogen
present in oil shales. Shale oil is a highquality crude oil that lies between layers of
shale rock, impermeable mudstone, or
siltstone.
ALCOHOL
Alcohol, any of a class of organic compounds
characterized by one or more hydroxyl groups
attached to a carbon atom of an alkyl group
(hydrocarbon
chain).
Alcohols
may
be
considered as organic derivatives of water in
which one of the hydrogen atoms has been
replaced by an alkyl group, typically represented
by R in organic structures.
PROPERTIES OF LIQUID FUELS
DENSITY
Density is defined as the ratio of the mass of the fuel to the volume of the fuel at a
reference temperature of 15°C. Density is measured by an instrument called a
hydrometer. The knowledge of density is useful for quantitative calculations and
assessing ignition qualities. The unit of density is kg/m3.
SPECIFIC GRAVITY
This is defined as the ratio of the weight of a given volume of oil to the weight of
the same volume of water at a given temperature. The density of fuel, relative to water,
is called specific gravity. The specific gravity of water is defined as one. Since specific
gravity is a ratio, it has no units. The measurement of specific gravity is generally made
by a hydrometer. Specific gravity is used in calculations involving weights and volumes.
VISCOSITY
The viscosity of a fluid is a measure of its internal resistance to flow. Viscosity
depends on the temperature and decreases as the temperature increases. Any numerical
value for viscosity has no meaning unless the temperature is also specified. Viscosity is
measured in Stokes / Centistokes. . The measurement of viscosity is made with an
instrument called a Viscometer. Viscosity is the most important characteristic in the
storage and use of fuel oil. It influences the degree of pre-heating required for handling,
storage and satisfactory atomization.
INSTRUMENTS USE TO MEASURE THE PROPERTIES OF LIQUID FUELS
HYDROMETER
Hydrometer is a device for measuring
some characteristics of a liquid, such as its
density (weight per unit volume) or specific
gravity (weight per unit volume compared
with water). The device consists essentially
of a weighted, sealed, long-necked glass
bulb that is immersed in the liquid being
measured; the depth of flotation gives an
indication of liquid density, and the neck can
be calibrated to read density, specific
gravity, or some other related characteristic.
VISCOMETER
Viscometer,
instrument
for
measuring the viscosity (resistance to
internal flow) of a fluid. In one version,
the time taken for a given volume of fluid
to flow through an opening is recorded.
In the capillary tube viscometer, the
pressure needed to force the fluid to flow
at a specified rate through a narrow tube
is measured.
III.
Materials

IV.
PC/Laptop
Formulas

Density
𝑘𝑔
𝑔
𝑔
Unit: 𝑚3 , 𝑐𝑚3 , 𝑚𝐿
𝜌=

𝑚
𝑉
Specific Gravity
𝑆𝑝𝑒𝑐𝑖𝑓𝑖 𝐺𝑟𝑎𝑣𝑖𝑡𝑦 =

𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑜𝑏𝑗𝑒𝑐𝑡 𝜌𝑜𝑏𝑗𝑒𝑐𝑡
=
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟
𝜌𝐻2 𝑂
Viscosity
Dynamic Viscosity – measures the ratio of the shear stress to the shear rate
for a fluid.
𝜇=
Units:
𝜏
𝛾
𝑑𝑦𝑛.𝑠 𝑘𝑔
𝑐𝑚
, 𝑚∙𝑠 , 𝑐𝑃, 𝑃(𝑝𝑜𝑖𝑠𝑒), 𝑃𝑎 ∙ 𝑠
Kinematic Viscosity – measures the ratio of the viscous force to the inertial
force on the fluid.
𝜈=
Units:
V.
𝑐𝑚2
𝑠
, 𝑐𝑆𝑡(𝑐𝑒𝑛𝑡𝑖𝑠𝑡𝑜𝑘𝑒𝑠),
𝑓𝑡 2 𝑚2
𝑠
,
𝑠
𝜇
𝜌
, 𝑆𝑡(𝑠𝑡𝑜𝑘𝑒𝑠)
Questions
1. The tool used to measure the mass of a substance or object is?
BALANCE
2. What laboratory apparatus is used to measure the volume of a liquid?
BURETTE
3. What is the unit for specific gravity?
DIMENSIONLESS
4. It is necessary to mention the temperature at which specific gravity is
calculated, because
a. Rigidity of the substance changes with temperature
b. Density of the substance changes with temperature
c. Mass of the substance changes with temperature
d. None of the mentioned
5. What is API gravity?
It is to measure how heavy or light a petroleum liquid is compared to water.
6. API gravity is necessary for the calculation of specific gravity of
petroleum products, because
a. Potential energy of petroleum products changes with temperature
b. Mass of petroleum products changes with temperature
c. Volume of the petroleum products changes with temperature
d. None of the above
7. What is viscosity and flow rate?
Viscosity is the resistance of a fluid to a change in shape or movement. Flow rate
is defined as the volume of fluid flowing through an area each second.
8. How is viscosity and density affected when a fluid is heated?
a. Viscosity increases and density increases
b. Viscosity decreases and density increases
c. Viscosity decreases and density decreases
d. Temperature has no effect on viscosity and density
9. Find the density of an unknown liquid in a beaker. The beaker's mass is
165 g when there is no liquid present. With the unknown liquid, the total
mass is 309 g. The volume of the unknown liquid is 125 mL.
Given: 𝑚𝑏 = 165 𝑔
𝑚𝑡𝑜𝑡 = 309 𝑔
𝑚𝑢𝑙 = ?
𝑝𝑢𝑙 = ?
𝑣𝑢𝑙 = 125 𝑚𝐿
Solution:
𝐹𝑜𝑟 𝑚𝑢𝑙 :
𝐹𝑜𝑟 𝑝𝑢𝑙 :
𝑚𝑢𝑙
𝑚𝑡𝑜𝑡 = 𝑚𝑏 + 𝑚𝑢𝑙
𝑝𝑢𝑙 =
𝑚𝑢𝑙 = 𝑚𝑡𝑜𝑡 − 𝑚𝑏
𝑝𝑢𝑙 = 125 𝑚𝐿
𝑚𝑢𝑙 = 309 𝑔 – 165 𝑔
𝑚𝑢𝑙 = 144 𝑔
𝑣𝑢𝑙
144 𝑔
𝑔
𝑝𝑢𝑙 = 1.152 𝑚𝐿
10. The density of gasoline is 736 kilograms per cubic meter. What is its
specific gravity?
Given:
𝑘𝑔
𝑝𝑔 = 736 𝑚3
𝑘𝑔
𝑝𝑤 = 1000 𝑚3
Solution:
𝑆. 𝐺 =
𝑆. 𝐺 =
𝑝𝑔
𝑝𝑤
736 𝑘𝑔/𝑚3
1000 𝑘𝑔/𝑚3
𝑆. 𝐺 = 0.736
VI.
Conclusion
Liquid fuels like furnace oil and LSHS (low sulphur heavy stock) are predominantly
used in industrial applications. The various properties of liquid fuels like density, specific
gravity, and viscosity can be measured by different measuring instruments like
hydrometer and viscometer. Liquid fuels can also be classified as fossil fuel, therefore,
some types of liquid fuels can be found naturally on ground or underneath the earth’s
surface.
VII.
References
 https://www.researchgate.net/publication/293212846_Liquid_fuels_Types_proper
ties_and_production
 https://www.sciencedirect.com/topics/earth-and-planetary-sciences/liquid-fuels
 https://www.investopedia.com/terms/p/petroleum
 https://www.sciencedirect.com/topics/neuroscience/coal-tar
 https://www.sciencedirect.com/topics/engineering/shale-oil
 https://www.britannica.com/science/alcohol
 http://ecoursesonline.iasri.res.in/mod/page/view.php?id=945
 https://www.britannica.com/technology/hydrometer
 https://www.britannica.com/technology/viscometer