Whats is the law of conservation of mass?

15 Answers

sciencesolve's profile pic

sciencesolve | Teacher | (Level 3) Educator Emeritus

Posted on

The law of conservation of mass states that the mass of one element that enters into reaction is equal to the mass of the same element that comes out from the chemical reaction.

The law of conservation of mass is valid in closed system, hence, in case of open systems, depending on energies that enter in of come out, the law of energy holds or not.

Hence, the law of conservation of mass states that mass is constant in a closed system.


thewanderlust878's profile pic

thewanderlust878 | Student, College Freshman | (Level 3) Salutatorian

Posted on

The law of conservation of mass (sometimes referred to as the principle of mass conservation) is as follows:

for any system closed to all transfers of matter and energy (both of which have mass), the mass of the system must remain constant over time, as system mass cannot change quantity if it is not added or removed. 

The law implies that mass can neither be created nor destroyed, although it may be rearranged in space, or the entities associated with it may be changed in form, as for example when light or physical work is transformed into particles that contribute the same mass to the system as the light or work had contributed.

Hope this helps!

sid-sarfraz's profile pic

sid-sarfraz | Student, Graduate | (Level 2) Salutatorian

Posted on

According to the law;

The amount of mass remains constant in;

  • The creation and separation of mixtures
  • No Creation and destruction of matter, only it changes forms 
  • Pure substances can be decomposed 

In other words, the total mass of universe remains constant and can be measured, whether matter is created or destroyed, whether mixtures are created or separated or pure substances decomposed, whatever the reaction but the mass of universe always remains constant.

Wiggin42's profile pic

Wiggin42 | Student, Undergraduate | (Level 2) Valedictorian

Posted on

The law of conservation of mass says that in a closed isolated system during a chemical reaction, mass is neither created nor destroyed; it only changes form. Another way of saying this is that products equal reactants. Whatever amount of matter you started with, that is how much matter you will end up with. There is a similar law for energy.

zumba96's profile pic

zumba96 | Student, Grade 11 | (Level 3) Valedictorian

Posted on

Also known as the principle of mass or matter or mass in a closed system that will remain constant over a period of time. Matter cannot be created or destroyed.

revolution's profile pic

revolution | College Teacher | (Level 1) Valedictorian

Posted on

The main principle of the law of conversation of mass is that mass can neither be created or destroyed, but it can be re-arranged in space or change into different types of particles, or the matter can be changed into different states, like solid, liquid or gas. It is also concluded that the mass of the reactants and the mass of the products must equal to each other, and cannot be completely different, as it would unbalance the chemical reaction.

bobolin's profile pic

bobolin | High School Teacher | (Level 1) eNoter

Posted on

One of the first conservation laws to be discovered was the conservation of mass (or matter). Suppose that you combine a very accurately weighed amount of iron and sulfur with each other. The product of that reaction is a compound known as iron(II) sulfide. If you also weigh very accurately the amount of iron(II) sulfide formed in that reaction, you will discover a simple relationship: The weight of the beginning materials (iron plus sulfur) is exactly equal to the weight of the product or products of the reaction (iron(II) sulfide). This statement is one way to express the law of conservation of mass. A more formal definition of the law is that mass (or matter) cannot be created or destroyed in a chemical reaction. A similar law exists for energy. When you turn on an electric heater, electrical energy is converted to heat energy.

cbaileyenotes's profile pic

cbaileyenotes | eNotes Newbie

Posted on

The law of conservation of mass refers to the classic scientific principle that, during chemical reactions, matter is neither created nor destroyed. In other words, as explained on the website for the International Society for Complexity, Information and Design, "[i]t is a different way of stating that though matter may change form, it can be neither created nor destroyed. The mass of the reactants must always equal the mass of the products."   This scientific principle was discovered in the 1780's by Antoine Lavoisier, though Mikhail Lomonosov had earlier expressed a similar concept. Thus this scientific rule is sometimes referred to as the Lomonosov-Lavoisier law. 

Please note that this term was already defined in enotes as: (n) a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system [syn: conservation of mass, conservation of matter, law of conservation of matter] See: http://www.enotes.com/uxl-science-encyclopedia/conservation-laws

Jyotsana's profile pic

Jyotsana | Student, Grade 10 | (Level 1) Valedictorian

Posted on

Law of Conservation of Mass is a relation stating that in a chemical reaction, the mass of the products equals the mass of the reactants.