Question

Describe law of conservation of matter.

Answer 1

The law of conservation of mass deals with the total mass before a change and the total mass after the change. Thus, when there is a transformation from initial state to final state, then the law of mass conservation relates the mass of initial state with the mass of final state.

Complete answer:
We can also call the law of conservation of matter as the principle of mass conservation. According to this law, for a closed system, there is no change in the mass of the system over a period of time. In other words, the mass of the system remains the same (unchanged, constant) over a period of time. The quantity of the system will not change if no matter is added to the system or if no matter is removed from the system. Thus, as time passes, the quantity of mass remains the same.
A closed system is one in which there is no exchange of either energy or matter.
Therefore, we can say that the mass can neither be created nor destroyed. We can only change one form of mass into another form. This change in form includes rearrangement in the space, or the change in the form of associated entities.
We can consider the phase changes as an example of the law of conservation of mass. If we melt one kilogram of ice, then we will exactly get one kilogram of liquid water. It will not happen that the mass of liquid water obtained is either less than one kilogram or it is more than one kilogram. Similarly, if we condense one gram of steam, we will get exactly one gram of liquid water.

Note: In a chemical reaction, we can use the law of conservation of mass to obtain the mass of products. For example, if we react with two grams of hydrogen with sixteen grams of oxygen, then we will obtain eighteen grams of water. wecan obtain eighteen when we add two and sixteen.