`1.80g` of a certain metal burnt in oxygen gave `3.0g` of its oxide `1.50g` of the same metal heated in steam gave `2.50g` of its oxide. Show that these illustrate the law of constant proportion .

Explanation

In the first sample of the oxide,
wt of metal `=1.80g, " wt of oxygen" = (3.0 - 1.80) g = 1.2g`
`:. ("wt. of metal")/("wt.of oxygen") = (1.80g)/(1.2g) = 1.5`
In the second sample of the oxide,
wt of metal `=1.50g` wt of oxgen `= (2.50 - 1.50) g = 1g`
`:. ("wt.of metal")/("wt of oxygen") = (1.50g)/(1g) = 1.5`
Thus in both smaples of the oxide the proportions of the weights of the metal and oxgen are fixed. Hence, the results follows the law of constant proportion
Note This law is not applicable in isotopes .