What is the percentage by mass of hydrogen in ordinary water (H₂O)?

Question

Quizplus · Accepted Answer

To find the percentage by mass of hydrogen in water, we need to know the atomic mass of hydrogen and the molecular mass of water. The atomic mass of hydrogen is 1 and the molecular mass of water is 18 (2 for hydrogen and 16 for oxygen).

So, the percentage by mass of hydrogen in water is calculated as follows:

(2 x 1) / 18 x 100% = 11.1%

Therefore, the best choice is B, which is 11%.

What Is the Percentage by Mass of Hydrogen in Ordinary