Define the law of conservation of mass and law of constant proportion?

Law of conservation of mass:

• This law was given by Antoine Laurent Lavoisier.
• According to this law, mass can neither be created nor be destroyed but can be transformed from one form to another.
• This law also states that during the chemical reaction the total mass of reactants is equal to the total mass of products. This means the total mass before and after a chemical reaction remains constant.

Law of constant proportion:

• This law was given by Proust.
• According to this law in a chemical substance, the elements are always present in a fixed proportion by their mass.
• For example, any water molecule is always made up of two hydrogen atoms and one oxygen atom in a ratio1:8.