Oh_Gee Full Member 10+ Year Member Joined Nov 15, 2013 Messages 1,738 Reaction score 1,189 Sep 7, 2014 #1 Members don't see this ad. will the reactant with less moles always be the LR? do the coefficients of the reactants matter?
Members don't see this ad. will the reactant with less moles always be the LR? do the coefficients of the reactants matter?
Cawolf PGY-2 10+ Year Member Joined Feb 27, 2013 Messages 3,469 Reaction score 2,287 Sep 7, 2014 #2 The substrate that is used up first. So it depend on coefficients. For example, 10A + B -----> A10B If there are 10 moles of A and 5 moles of B, the LR will be A even though it has more moles. The reaction will use 10 moles of A and only 1 of B, leaving 4 moles of B. Upvote 0 Downvote
The substrate that is used up first. So it depend on coefficients. For example, 10A + B -----> A10B If there are 10 moles of A and 5 moles of B, the LR will be A even though it has more moles. The reaction will use 10 moles of A and only 1 of B, leaving 4 moles of B.
Oh_Gee Full Member 10+ Year Member Joined Nov 15, 2013 Messages 1,738 Reaction score 1,189 Sep 7, 2014 #3 Cawolf said: The substrate that is used up first. So it depend on coefficients. For example, 10A + B -----> A10B If there are 10 moles of A and 5 moles of B, the LR will be A even though it has more moles. The reaction will use 10 moles of A and only 1 of B, leaving 4 moles of B. Click to expand... so if you were given grams of A and B and you calculated that you have 1 mol A and 3 mols B, A would still be the LR? and .1 mols of A10B will be made? Upvote 0 Downvote
Cawolf said: The substrate that is used up first. So it depend on coefficients. For example, 10A + B -----> A10B If there are 10 moles of A and 5 moles of B, the LR will be A even though it has more moles. The reaction will use 10 moles of A and only 1 of B, leaving 4 moles of B. Click to expand... so if you were given grams of A and B and you calculated that you have 1 mol A and 3 mols B, A would still be the LR? and .1 mols of A10B will be made?
Cawolf PGY-2 10+ Year Member Joined Feb 27, 2013 Messages 3,469 Reaction score 2,287 Sep 7, 2014 #4 Yup exactly. You can calculate your moles and then use dimensional analysis to check for the limiting reagent. Given 1 mol A and 3 mol B 1 mol A * (1 mol A10B/10 mol A) = .1 mol A10B 3 mol B * (1 mol A10B/1 mol B) = 3 mol B You can only go as far as your weakest link! So then we can say that a reaction creating .1 mol A10B * (1 mol B/1 mol A10B) = .1 mol B will be used So we started with 3 mol B and used .1 mol B = 2.9 mol B remaining. Upvote 0 Downvote
Yup exactly. You can calculate your moles and then use dimensional analysis to check for the limiting reagent. Given 1 mol A and 3 mol B 1 mol A * (1 mol A10B/10 mol A) = .1 mol A10B 3 mol B * (1 mol A10B/1 mol B) = 3 mol B You can only go as far as your weakest link! So then we can say that a reaction creating .1 mol A10B * (1 mol B/1 mol A10B) = .1 mol B will be used So we started with 3 mol B and used .1 mol B = 2.9 mol B remaining.