Law of Conservation of Mass - Examples, FAQs

Law of Conservation of Mass - Examples, FAQs

Vishal kumarUpdated on 02 Jul 2025, 04:31 PM IST

The Law of Conservation of Mass is a core objective in physics and states that in any physical or chemical change, the mass of the system remains constant, attribute mass, virginity or cause, within any closed system, such mass can neither be created nor destroyed. This law is essential in the explanation of various phenomena. From the simplest laboratory chemical processes to the most complex geophysical processes such as the hydrological cycle, this law can be appreciated. For example, a simple cooking exercise, where the combined weight of all ingredients is the same as the weight of the cooked dish and the steam coming off it serves as a demonstration of this principle in practice. These concepts and others like them help to explain the universe in physics and chemistry, which is why these concepts established and upheld mass conservation.

Law of Conservation of Mass - Examples, FAQs
law of conservation of mass

Law of Conservation of Mass

The Law of Conservation of Mass states that "mass can neither be created nor be destroyed in a reaction." The total mass shall always be retained from the start of the reaction till the end.

According to this law, matter cannot be created nor destroyed, also known as the law of indestructibility of matter.

Law of Conservation of Mass Formula

The formula for the law of conservation of mass is given by,

$$
\begin{aligned}
& \frac{\delta \rho}{\delta t}+\nabla \cdot(\rho v)=0 \\
& \rho \text { is density } \\
& \mathrm{t}=\text { time }
\end{aligned}
$$
$\nabla$ = divergence

$v=$ flow velocity

Law of Conservation of Mass Examples

  • Combustion process: Wood burning is a mass conservation process because it contains oxygen, carbon dioxide, water vapor, and ashes.
  • Chemical reactions: To make one molecule of H2O (water) with a molecular weight of 10, hydrogen with a molecular weight of 2 is combined with oxygen with a weight of 8 preserving mass.
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Frequently Asked Questions (FAQs)

Q: What role does the Law of Conservation of Mass play in understanding the formation of stars and planets?
A:
The Law of Conservation of Mass is crucial in astrophysics. It explains how matter in nebulae coalesces to form stars and planets. While some mass may be converted to energy in stellar processes, the total mass-energy of the system is conserved.
Q: How does the Law of Conservation of Mass relate to the concept of mass spectrometry?
A:
Mass spectrometry relies on the Law of Conservation of Mass. It measures the mass-to-charge ratio of ions, allowing scientists to determine the composition of a sample. The total mass of all fragments equals the mass of the original molecule.
Q: How does the Law of Conservation of Mass apply to the process of cellular respiration?
A:
In cellular respiration, the total mass of reactants (glucose and oxygen) equals the total mass of products (carbon dioxide and water). While energy is released, no mass is lost; it's simply rearranged into different molecules.
Q: What implications does the Law of Conservation of Mass have for the field of forensic science?
A:
In forensic science, the Law of Conservation of Mass is crucial for analyzing crime scenes and evidence. It ensures that all matter at a crime scene is accounted for, helping investigators trace the origins and transformations of physical evidence.
Q: How does the Law of Conservation of Mass relate to the concept of yield in chemical reactions?
A:
The concept of yield in chemical reactions is based on the Law of Conservation of Mass. The actual yield of a product can be compared to the theoretical yield (calculated assuming complete conversion of limiting reagent) to determine the reaction's efficiency.
Q: Can the Law of Conservation of Mass explain why the mass of a plant increases as it grows?
A:
Yes, the increase in a plant's mass as it grows demonstrates the Law of Conservation of Mass. The plant gains mass by incorporating matter from its environment: carbon dioxide from the air, water and minerals from the soil, all converted into plant biomass through photosynthesis.
Q: What role does the Law of Conservation of Mass play in understanding the nitrogen cycle?
A:
The Law of Conservation of Mass is fundamental to the nitrogen cycle. It ensures that the total amount of nitrogen in the biosphere remains constant as it cycles through various forms (atmospheric N₂, ammonia, nitrates) and between organisms and the environment.
Q: How does the Law of Conservation of Mass relate to the concept of stoichiometry in chemistry?
A:
Stoichiometry, which deals with the quantitative relationships between reactants and products in chemical reactions, is based on the Law of Conservation of Mass. It allows chemists to calculate the amounts of reactants needed or products formed in a reaction.
Q: Can the Law of Conservation of Mass help explain the formation of sedimentary rocks?
A:
Yes, the Law of Conservation of Mass applies to the formation of sedimentary rocks. The mass of sediments that form the rock equals the mass of eroded material from the source rocks, minus any dissolved minerals carried away by water.
Q: How does the Law of Conservation of Mass relate to the concept of limiting reagents in chemical reactions?
A:
The concept of limiting reagents is based on the Law of Conservation of Mass. The reagent that's completely consumed determines the amount of product formed, ensuring that mass is conserved and no excess atoms are created or destroyed.