THESE NOTES BELONG TO:

NAME ______DATE ______PERIOD 1 2 3 4 5 6 7

LIMITING “REAGENTS”

Bike Shop

in stock: 10 frames 14 wheels

assembly requires __ frame + __wheels 1 bicycle

what limits production? (i.e. what runs out first?)

___ fr ÷ ___ fr/bike = ___ bikes

___ wh ÷ ___ wh/bike = ___ bikes *

·  can only make this many (Why?)

Shake Stoichiometry

ex: strawberry banana milkshake

RECIPE for 1 SHAKE:

1 banana + 5 berries+ 2 scoops i.c. + 8oz milk

10 bananas and plenty of the other stuff yields __ shakes

25 strawberries à ___ shakes

8 scoops ice cream requires ___ strawberries

5 bananas, 36 strawberries, 10 scoops i.c. would need how much milk? ______anything leftover? ______

LIMITING REAGENT-CH12

Industry – must use correct proportions

* prevent waste (profit margin)

* purity of product

Example: production of ammonia

N2(g) + 3H2(g) à 2NH3(g)

Equation tells the proportions of N2, H2, and ammonia.

Coefficients are in a 1:3:2 ratio , (like a recipe)

could represent molecules of each or moles of each

Fill in the following:

1N2(g) + 3H2(g) à 2NH3(g)

_____ mole _____moles ______moles

_____ g ______g ______g

_____ L ______L ______L

QUESTIONS: What will happen if 2.0 mol of H2 and

2.0 mol of N2 are mixed and reaction occurs?

a)  How much ammonia could be produced from all the H2?

b)  How much ammonia could be produced from all the N2?

c)  How much ammonia will be produced from this mix?

d)  Will anything be left over (unreacted)? What & how much?

e)  Which reactant is the “LIMITING REAGENT” (LR) ?

f)  Which reactant is in excess (XS)