Stoichiometry

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: www.geocities.com Balanced equation: N2 (g) + 3H2 (g) -> 2NH3 (g)

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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 http://www.bristoljpg.co.uk/2004/suspension-bridge.jpg

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 2.02 g H2 1 mol. H2 = 2.16 g H2 needed to react with 10.0 g N2

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 17.0 g NH3 1 mol. NH3 = 12.1 g NH3 can be made with 10.0 g N2

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 N2 + 2.16 g H2 =12.1 g NH3 ? 12.16 g =12.1 g ? yes, to within + 0.1 g http://www.pinegloproducts.com/catalog06/productscatalog/864oz/glass_ammoniacleaners/ammonia_pine.gif http://www.channel4.com/4homes/media/0-9/4homes_mag/medium/cleaning_chemfree_simple_md.jpg