Question

What is the mass of `3.54*10^24` molecules of rubidium oxide?

Answer 1

It is a fact that `N_A` `Rb_2O` particles have a mass of `186.94*g`.

Explanation:

Given that `6.02214xx10^24` formula units of `Rb_2O` have a mass of `186.94*g`, the given number of `Rb_2O` formula units have a mass of:

`(3.54xx10^24" formula units of " Rb_2O)/(6.02214xx10^24" formula units "mol^-1*Rb_2O)`

`=`

`??" moles of rubidium oxide"`

So the mass `~=` `1/2` `mol` `xx186.94*g*mol^-1, "i.e. "93*g`.