Question

How many moles of hydrogen atoms are present in one mole of water?

• A. four
• B. one
• C. three
• D. two

Answer 1

The correct option is D two

A mole is a number just like a dozen or a century. A dozen has 12 things, similarly a mole has 6.023 x ${10}^{23}$ entities (atom, molecule and particles).

1 mole of water contains 6.023 x ${10}^{23}$ $H_{2}O$ molecules.

Each $H_{2}O$ molecule has two H atoms and one O atom. So, 1 mole of water which is 6.023 x ${10}^{23}$ $H_{2}O$ molecules will have 2 x [6.023 x ${10}^{23}$] hydrogen atoms and 6.023 x ${10}^{23}$ oxygen atoms.

So, one mole of water will have two moles of hydrogen atoms and one mole of oxygen atoms.