Question

An astronaut gets thirsty on the moon. So, he makes water by mixing hydrogen and oxygen. Will the mass ratio of hydrogen to oxygen present in the water that he made on moon will be same as that on the earth?

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

Answer 1

The correct option is B

It will be the same.

According to 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.
$2H_2$ +$O_2$ $\to 2H_{2}O$

For eg: The chemical formula of water is $H_{2}O$, which means water requires only 2 molecules of hydrogen and 1 molecule of oxygen irrespective of its location. The ratio of mass of hydrogen to that mass of oxygen is always 1:8, whatever be the source of water.