1. Stoichiometry

2. The Haber Process N2 (g) + H2 (g) -> NH3 (g)
hydrogen gas and nitrogen gas combine to form ammonia gas
Skeleton equation:
N2 (g) + H2 (g) -> NH3 (g)
Pix:
Balanced equation:
N2 (g) + 3H2 (g) -> 2NH3 (g)

4. N2 (g) + 3H2 (g) -> 2NH3 (g)
How many grams of hydrogen would we need to convert 10.0 g of nitrogen into ammonia?
How many grams of ammonia can be made?
OFF RAMP: change moles of what you want back into grams
ON RAMP: change grams of what you have into moles
BRIDGE: change moles of one material into moles of another

5. N2 (g) + 3H2 (g) -> 2NH3 (g) 10.0 g N2 x 1 mole N2 28.0 g N2
How many grams of hydrogen would we need to convert 10.0 g of nitrogen into ammonia?
N2 (g) + 3H2 (g) -> 2NH3 (g)
10.0 g ?
ON RAMP: change grams of what you have into moles
BRIDGE: change moles of one material into moles of another
OFF RAMP: change moles of what you want back into grams
10.0 g N2 x 1 mole N2
28.0 g N2
x 3 mol. H2
1 mol. N2
x g H2
1 mol. H2
= 2.16 g H2 needed to react with 10.0 g N2

6. How many grams of ammonia can be made from 10.0 g nitrogen?
N2 (g) + 3H2 (g) -> 2NH3 (g)
10.0 g ?
ON RAMP: change grams of what you have into moles
BRIDGE: change moles of one material into moles of another
OFF RAMP: change moles of what you want back into grams
10.0 g N2 x 1 mole N2
28.0 g N2
x 2 mol. NH3
1 mol. N2
x g NH3
1 mol. NH3
= 12.1 g NH3 can be made with 10.0 g N2

7. N2 (g) + 3H2 (g) -> 2NH3 (g) 10.0 g N2 + 2.16 g H2 =12.1 g NH3 ?
Check your answer using Conservation of Mass.
10.0 g N g H2 =12.1 g NH3 ?
12.16 g =12.1 g ?
yes, to within g