Consider the following reaction: 2K(s) + Cl2(g) -> 2KCl(s). If 8 mol potassium reacts with 10 mol chlorine, how much chlorine will be left over after the reaction?

I really do not know how to go about solving this, I am very new to this unit. Thanks!

3 answers

It takes 2K for each Cl2
so, 8 mol K will react with 4 mol Cl2
That leaves 6 moles of Cl2 left over
How could I be so clueless? Thank you so much!
Note that this is a limiting reagent problem. All of the K reacts (that's the limiting reagent) so it takes as much Cl2 as it needs and you have some Cl2 remaining.