What are moles in chemistry?

First write a balanced chemical equation: 2K + Br2 - - - > 2KBR Find the limiting reactant by using the moles of each element and determining which one gives you the smallest number of moles of potassium bromide. 2.92 mol K (2 mol KBr/2 mol K) = 2.92 mol KBr 1.78 mol Br2 (2 mol KBR/1 mol Br2) = 3.56 mol KBr potassium is your limiting reactant so the max. number of moles of KBr that can be produced is 2.92 mol of KBr

It's the weight of avogadro num from atoms