Question

How do you find the number of molecules or ions of 4.5 mol `BCl_3`?

Answer 1

The number of MOLECULES of `BCl_3` is `4.5` `xx` `N_A`, where `N_A` is Avogadro's number.

Explanation:

In one mole of stuff (atoms, molecules, eggses), there are `N_A` individual items of that stuff.

So, there are `4.5` `xx` `N_A` `BCl_3` molecules; i.e. `4.5` `xx` `6.022xx10^23` `~=` `27 xx 10^23` individual molecules of `BCl_3`. How many actual ATOMS in this molar quantity of `BCl_3??`