posted by Kay .
a.) Assume that you had 100 nuts (N) and 75 bolts (B). How many NB molecules could you make by screwing one nut onto each bolt?
b.) How many N2B molecules could you make by screwing two nuts onto each bolt?
for a) there is a 1:1 ratio. The bolts are the limiting reactant (which means you will run out of them before you use up all of the other) therefore you can only have 75 NB molecules.
b) for every N2B you have to have 2 nuts to every 1 bolt which is a 2:1 ratio so you divide the 100 nuts by 2. that will give you 50 nuts which will then become your limiting reactant. So you can make 50 N2B molecules.