Question

to which classes of matter-elements compounds and/or mixtures- do the following laws apply

a.law of mass conservation b. law of definite composition c. law of multiple proportions

Answer 1

a) law of mass conservation :

Matter can neither be created nor destroyed, whether it is an element, compound, or mixture.

so

this law applies to all substances — elements, compounds and mixtures.

b) law of definite composition :

The law of definite composition applies to compounds only,

because it refers to a constant, or definite composition of elements within a compound.

c) law of multiple proportions:

The law of multiple proportions applies to compounds only

because it refers to the combination of elements to form compounds.