What is the limiting reactant if 5.00 g H2 is mixed with 10.00 g O2?

Question

 

If 5.00 g of hydrogen reacts completely 44.1 g of water is produced.

 

If 10.00 g of oxygen reacts completely 11.3 g of water is produced.

Answer 1

Hi Austin. Awesome! So this problem actually has the hard problem solved already, which is to calculate how much product will be produced for a COMPLETE reaction of either of the reactants. I'll paste those results below:

5.00 g of H2 reacts completely to make 44.1 g H2O

10.00 g of O2 reacts completely to make 11.3 g of H2O

now, these are theorhetical calculations, because one of these reactants (H2 or O2) will be the limiting reactant, which means the other reactant will NOT lead to producing it's full amount of H2O/product. the actual total of product/H2O produced here would be whatever the limiting would have produced theoretically.

'simply', now, choose the reactant that theorhetically makes LESS product (this is always how to choose your limiting reactant). so, ANSWER = O2, oxygen is the limiting reactant.

fun follow up Q: how much hydrogen is left over?