Inorganic chemistry

What is the simple definition of density?

How density is measured ? The  density  is the mass per unit volume of a substance. It is calculated by dividing the object’s mass by its volume.

Density = mass / volume

It exists to determine the amount of material that is present in a given volume unit.

What would you understand if they told you that lead has a higher density than aluminum? The explanation is that in a given volume of lead there is more matter than in the same amount of aluminum.

Content Index:

• 1 Features
• 2 Example
• 3 Importance
• 4 Importance of water density

Important Features :

• It represents the mass of a body divided its volume.
• It is usually expressed in gram per cubic centimeter (g / cm 3 ) or kilogram per cubic meter (kg / m 3 ).
• It is a concept widely used in physics and chemistry to analyze substances.
• The density of water is 1 g / cm 3 . In other words, any substance whose density is less than that of water will float and if it is higher it will sink.
• Its mathematical expression is given by ρ = m / v or δ = m / v . Where ρ, δ is the density, m is the mass and v the volume.

Examples :

We can characterize a substance by its density. The density of solids and liquids is expressed in grams per cubic centimeter (g / cm3). Let’s look at the density of some compounds:

• Water  ………………………………… 0.997 g / cm3
• Ethyl alcohol ……………………… 0,789 g / cm3
• Aluminum  ………………………… .. 2.70 g / cm3
• Lead …………………………… ..11.3 g / cm3
• Diamond  …………………………… .3,5 g / cm3
• Whole milk ……………………… .1.03 g / cm3
• Mercury  …………………………… 13.6 g / cm3

Importance :

It is a physical property  of great importance in the characterization, identification and use of substances or materials .

Many chemical processes, such as starch fermentation, acid manufacturing and ammonia oxidation, are controlled by measuring density.

Today, the water content in the hydrated alcohol used as fuel is controlled at the service stations through the density of the hydro-ethanol mixture.

Commercial polymers, such as polyethylene, are commercially characterized by their densities. Simple substances of many chemical elements can be identified by their density values.

Importance of water density

The density of liquid water is equal to 1.0 g / cm3, while the density of ice is equal to 0.92 g / cm3.

The result is that ice floats on water, 92% of its volume below the surface of the water and 8% above the surface.

Water density in relation to ice density  is important for the maintenance of animal and plant life in the oceans.