Define the law of multiple proportions. Explain it with two examples. How does this law point to the existance of atoms ?

Define the law of multiple proportions. Explain it with two examples.

1.	Define the law of multiple proportions. Explain it with two examples. How does this law point to the existance of atoms ?
Answer» Solution :Law ofmultiple proportions was first studied by Dalton in 1803 which may defined as follows : When two or more ELEMENTS combine to form two or more chemical compounds, then the MASSES of one of the elements which combine with a fixed mass of the other, bear a simple RATIO to one another . e.g., hydrogen combines with OXYGEN to form two compounds, namely, WATER and hydrogen peroxide. `{:("Hydrogen",+,"Oxygen",rarr,"Water",),(""2g,,""16g,," " 18g,):}` `{:("Hydrogen",+,"Oxygen",rarr,"Hydrogen peroxide",),(" 2g",," 32 g",,"34 g",):}` Here, the masses of oxygen which combine with a fixed mass of hydrogen bear a simple ratio, i.e., `16:32` or `1:2` . As we know that, when compounds mixed in different proportion, then they form different compounds. In the aboveexamples when hydrogen is mixed with different proportion of oxygen, then they form water or hydrogen peroxide. It shows that there are constituents which combine in a definiteproportion. These constituents may be atoms. Thus, law of multiple proportions shows existence of atoms which combine into molecules.