## HW Question M.5

Isabel Bellon 4F
Posts: 30
Joined: Fri Sep 28, 2018 12:27 am

### HW Question M.5

How do we know that BrF3 is the excess reactant in this problem? I thought ClO2 was the excess reactant due to 12 moles of it vs. 5 moles of BrF3?

Gary Qiao 1D
Posts: 66
Joined: Fri Sep 28, 2018 12:26 am

### Re: HW Question M.5

BrF_3 is the excess because although there are 12 moles of ClO_2 present to react with only 5 moles of BrF_3, the chemical equation
(6 ClO_2(g) + 2 BrF_3(l) --> 6 ClO_2F(s) + Br_2(l)) shows that 6 moles of ClO_2 would react with 2 of the moles of BrF_3 for one reaction. After two reactions, 12 moles of ClO_2 would all be used up while only 4 moles of BrF_3 would be used in the two reactions. This leaves 1 mole of BrF_3 excess.

Fayez Kanj
Posts: 62
Joined: Fri Sep 28, 2018 12:18 am
Been upvoted: 1 time

### Re: HW Question M.5

Hello!

A quick and easy way to determine the limiting reactant is to first calculate the number of moles of each reactant, then divide the number of moles of each reactant by its respective stoichiometric coefficient. The smallest number will indicate which reactant is limiting and is not present in enough of a quantity

Hope that helps! :)