Question

Question #ce668

Answer 1

`1.7 * 10^22` molecules of `"H"_2"O"`

Explanation:

Given `"0.5 g"` of `"H"_2"O"` and using the molar mass of water

`M_( "H"_2"O") = "18.01528 g/mol"`

you have

`(0.5cancel("g"))/(18.01528cancel("g")"/mol") = "0.02775 moles"`

There are `6.022 xx 10^23` particles in a mole.

`(6.022 * 10^23"molecules H"_ 2"O")/(1cancel("mol")) * 0.02775cancel("moles") = 1.7 * 10^22"molecules H"_2"O"`