Mensuration is a very integral process in the day to day activities in most practical fields in both, the corporate and academic field. Density and volume are both important terms. Both of them are quantifiable quantities that describe the physical properties of an object. However, it is necessary for the object that is to be measured for both of these properties to have mass. Mass is an essential component for the calculation of various physical quantities and not just density and volume.

**Density vs Volume**

The difference between density and volume is that density tells how closely are the molecules packed in an object while volume tells us about the physical space occupied by an object.

Density is defined as the amount of mass that is present in an object for a given volume. Density is used to establish and understand the relationship between mass and volume. Physically, it tells us how closely are the molecules of the substance are packed to each other. A high density means that the molecules are packed closely.

Volume, on the other hand, is defined as the amount of physical space that an object occupies. Volume comes in handy for practical use in planning activities when we use it to determining how much space something is going to occupy. Volume is an essential measure for liquids since they do not have a definite shape, and hence can not be measured in terms of area.

**Comparison Table Between Density and Volume**

Parameters of Comparision | Density | Volume |

Definition | It is the amount of mass present in a given volume of space. | Volume is the space occupied by an object. |

Nature | Intensive in nature. | Extensive in nature. |

SI unit | Kilograms per cubic meter (kg/m^{3}) | Cubic meter (m^{3}) |

Formula | mass/volume | length^{3} |

Relation with Temperature | Decreases with an increase in temperature. | Increases with an increase in temperature. |

**What is Density?**

Density is a measure of mass per unit volume. This is the most standard definition of density and is in fact the simplest too. In everyday life, when we talk about how dense an object is, or how dense a liquid is, we mean to say that the individual molecules are packed very closely in the liquid. And when the molecules are packed closely, it means that more molecules can fit in a given amount of space.

When more molecules are able to fit in the given amount of space, it automatically results in more mass being occupied in that amount of space. We measure space in terms of volume, as it is a three-dimensional quantity, and so, more mass in a given amount of space results in more mass in a given amount of volume. To standardize this measurement, we take into account the mass present in a unit quantity of volume and this leads us to derive the formula for Density. The formula for density is

D = m/V

Where,

- D = Density
- M = Mass
- V = Volume

Density decreases as temperature increases. This can be understood as when the temperature increases, the energy in the molecules of the substance increase and hence tend to drift away from each other, and thus, it increases the volume of the substance. Since, density is inversely proportional to volume, so as volume increases, density decreases. This decrease is highest in gases, followed by liquids and then solids.

Density is an important day to day physical quantity, which comes into use in a number of ways. The most well-known use of density is trying to determine whether an object will float in water or not. This is more prevalent in the shipping industry, as they need to keep the density of the shipment lower than the density of water.

Another use is the making of consumer products like condensed milk, where the density of the product matters. Having a general idea of density helps in a similar number of day-to-day cases.

**What is Volume?**

Volume is the physical three-dimensional space that is occupied by an object. When we are dealing with the volume of stuff that needs to act as containers, we often use the term capacity instead. Volume is an important quantity and very frequently used on a daily basis.

We use volume when we need to buy a bottle of water, we use volume when we need to buy a refrigerator. We keep the volume of the boot space of a car in mind when we purchase a car. Volume is very crucial in some cases like the making and designing of an airplane or the designing of a ship.

The formula for volume is as follows:

V = L^{3}

Where,

- V = Volume
- L = Length

Length is a basic fundamental quantity, and since we take the cube of mass to calculate volume, hence volume is a three-dimensional quantity.

For simple objects, whose sides are easy to calculate, such as a cube or a cuboid, in those cases, the calculation of volume is really simple.

- In the case of a cube, the formula for volume is (length of a side)
^{3}. - In the case of a cuboid, the formula for volume is (length X breadth X height)

In either case, the dimension results to be L^{3}.

**Main Differences Between Density and Volume**

- The main difference between density and volume is that density tells us how much mass is present in a given amount of space, and volume tells us about the space occupied by an object.
- Density is intensive in nature, which means that it is an internal property of the substance. Volume is extensive.
- SI unit of density is Kilograms per cubic meter (kg/m
^{3}) while the SI unit of volume is cubic meter (m^{3}). - The formula for density is (mass/volume). The formula for volume is (length)
^{3}. - Density decreases with an increase in temperature, while volume increases with an increase in temperature.

**Conclusion**

Density and Volume are both two very significant quantities that are measured and applied in the field of academics, engineering, etc. There are some cases where these two units might seem confusing to people and hence might be used in a wrong manner. However, it is important to know the difference properly when using these terms for academic or official use.

**References**

- https://acsess.onlinelibrary.wiley.com/doi/abs/10.2136/sssabookser5.1.2ed.c13
- https://www.spiedigitallibrary.org/conference-proceedings-of-spie/2359/0000/Volume-visualization/10.1117/12.185241.short?SSO=1

Table of Contents