Methods for Measuring Density of Liquids and Solids

Introduction
Density, or more precisely, density of volumetric mass, a substance is its mass per unit volume.
The most commonly used symbol for density is ρ (Greek letters rho in lowercase), although
Latin letters may also be used. Mathematically, density is defined as a mass divided by volume.
In all material circumstances, density is a physical parameter that performs a significant part,
whether solid, fluid or gas. The density of solids and fluids is the focus of this study. This report
explains what "density" is, how these parameters are defined and measured, the density
measurement history, the different accessible techniques and also how to achieve the highest
density outcomes using a good density measurement technology. The general Equation for
calculating density is as given below
ρ= Mass
volume [ k g
m3 ]
The actual density ρ in kg / m3 or g / cm3 of liquid is defined as the mass m divided by its
volume V. The mass is related to weight in vacuum and is not dependent on external conditions
such as buoyancy in air or gravity.
Aims and objectives
The objectives of the report are as listed below
1. Research and analyse the methods listed below used in finding density for liquid and
solids. These methods include;
1.1 measurement of mass and volume then calculate
1.2 displacement
1.3 hydrometer
1.4 pycnometer
1.5 Digital density metre
2. Set out the strengths and weakness of each method
3. Evaluate the suitability of method in finding density for both liquid and solids
Density measuring Methods
The various methods used in measuring density have been discussed as follows1;
1. measurement of mass and volume then calculate
This method generally gives the raw definition of density. It involves measuring the mass and
volume of liquid/solid using the available techniques then calculate the density
1 "Lab 1 - Density Determinations and Various Methods to Measure Volume",
in
Webassign.net, , 2019,
<http://www.webassign.net/question_assets/ucscgencheml1/lab_1/manual.html> [accessed
30 June 2019].

procedure
consider the solid and liquid to be used as show on picture, the first approach is to measure the
masses of the quantities
Figure 1 measuring the mass of the solid and liquid 2
the second activity is to measure the volume of the given solid and liquids
Figure 2 measuring volume of the liquid
Results
solid
Mass of solid rock = 38.718 grams
Volume of solid rock was measured as, volume = 20 cm3
Liquid
Measured Mass of liquid =100grammes
Measured Volume of liquid = 100mm3
Calculations
To find density, we use the formulae provided below
2 "How to Measure Mass & Density", in
Sciencing, , 2019,
<https://sciencing.com/measure-mass-density-7820720.html> [accessed 30 June 2019].

Density ( ρ ) = Mass
volume [ k g
m3 ]
For liquids
ρ=100
100 [ g
cm3 ]
Densityofliquidρ=1 [ g
c m3 ]
For solid
ρ=38.718
20 [ g
cm3 ]
ρ=1.9359 [ g
cm3 ]
Suitability
This method is suitable for measuring density of liquids and solids
advantages
1. can be used for both liquids’ gases, this is because both the mass and volume of
liquids and can be evaluated. The fact that there are so many instruments that can be
used to get the quantities
2. No tech skills needed, just simple mathematics for calculation
Disadvantages
1. Too tedious, since it involves calculations
2. Finding volume for irregular solids makes it not always relevant density in solids
3. The mass of container used in keeping the liquid should be known first, this add more
unnecessary steps needed

2. Displacement
Archimedes began to find density by displacement of water. Density calculation using the
formula D= m μv, where D is the density , m is the mass and v the volume. Find the mass on an
equilibrium scale and use the transfer of water to discover an uneven object quantity. The
volume of displaced water the quantity of water that rises when an object placed in water. The
displaced water is equivalent to the object volume. If a cynically submerged object displaces the
water level from 40 ml to 90 millilitres, the volume shift of 50 ml is equivalent to that of the
cubic centimetres for the object.
Figure 3 finding mass of the object
Example
Procedure
Find mass-A balance scale must be used to detect mass. Most mass scales counter a known mass
with an unidentified object. For example, three beams and real balances, such as the classical
scale seen in an assay desk.
Find volume- use a standard formula to find the volume of ordinary geometric objects. The
volume of the box is equal to the length by width times the height. However, not every object
matches the formula. For objects with this irregular shape, use the water displacement method to
find the volume of the object.