Question

An astronaut on the surface of the moon is thirsty. He decides to synthesize water by mixing hydrogen and oxygen. Will the mass ratio of hydrogen to oxygen in water remain the same on moon's surface as that on earth?

• A. It will be different.
• B. It will be same.
• C. On the moon, water will have lighter mass than on earth.
• D. On the moon, water will have heavier mass than on earth.

Answer 1

The correct option is B

It will be same.

According to the law of constant proportion, in a given chemical compound the elements are always present in definite proportions by mass. So the mass ratio of the water will be same irrespective of place.

For example, the chemical formula of water is H₂O, which means water requires only 2 molecules of hydrogen and 1 molecule of oxygen irrespective of its location. The ratio for mass of hydrogen to the mass of oxygen is always 1:8 irrespective of the method or source from which it is obtained.