On heating of 4.9g of `KClO_(3),1.92g" of "O_(2)` is evolved and 2.97g of `KCl` is obtained as a residue show that these data illustrate the law of conservation of mass.

Explanation

Reaction: `underset(2.9g)(2KClO_(3)) to underset(2.97g)(12KCl)+underset(1.92g)(3O_(2)uarr)`
Total mass of the reactant `(KClO_(3))=4.9g`
Total mass of the products `O_(2)+KCl =(1.92+297)g`
=4.89g
`therefore`Difference in mass between the reactant and products
=(4.9-4.89)g=0.01g.
this small difference is due to experimental error. other-wise these data illustrate law of conservation of mass.