Question

A sample of pure water whatever the source always contains ......... by mass of oxygen and 11.1% by mass of hydrogen​

Answer 1

Answer:

contains the mass of oxygen

Answer 2

Answer:

Explanation:

According to the law of definite proportions or constant composition, in all the pure samples of a particular chemical compound, the constituent elements are generally combined in the same proportions by mass. The combination is regardless of the mode or origin of the of the compound.

A sample of pure water,whatever the source will be, will always contain 88.8% by mass of oxygen and  11.1% as the mass of hydrogen.

Both the gases are divided in a constant ratio. Since, H2O contains the elements H and O in a fixed ratio by mass, this explains the law of constant composition, thus they are divided in a ratio of 1:8.

Thus, the mass of Oxygen is 88.8%.