State and explain law of definite proportions

Explanation

Law of definite proportions states that, a given compound always contains exactly the same proportion of elements by weight. For example, carbon dioxide may be formed in a number of ways as follows
(i) By burning of coke in air
`underset(("coke"))(C )+ underset(("air"))(O_(2)) overset("heat")rarr CO_(2)`
(ii) By decomposition of lime stone on heating
`CaCO_(3) overset("heat")rarr CaO + CO_(2)`
In the above two samples of `CO_(2)`, ratio of carbon and oxygen is same, ie., `12:32 or 3: 8` by weight.