Question

How many atoms of hydrogen are there in 18 g of water?

Answer 1

`~~1.2*10^24` atoms of hydrogen

Explanation:

Water has a molar mass of `18.01528 \ "g/mol" ~~ 18 \ "g/mol"`.

So, in `18 \ "g"` of water, there will be

`(18cancel"g")/(18cancel"g""/mol")=1 \ "mol"`

Since water has a chemical formula of `H_2O`, there will be `2` moles of hydrogen in every mole of water.

In one mole of water, there will exist approximately `6.02*10^23` water molecules.

So, there will be a total of `6.02*10^23*2~~1.2*10^24` hydrogen atoms.