2 Foldable Obtain 3 sheets of paper. Stagger the pages about ¾ of an inch.Fold over so you have multiple flaps.
3 Titles of Pages Stoichiometric Calculations Mole to Mole Mole to Mass / Mass to MoleMass to MassLimiting ReactantPercent Yield
4 Page 1 - Top Open your book, on the top flap, write the following: Steps in all stoichiometric calculations:Write a balanced equationIdentify the known and unknown, what do you have and what are you trying to find?Set up the problem with the given informationIdentify the mole ratioCheck your answer, does it make sense?
5 Page 1 – Bottom – Mole to Mole Mole of A to Mole of BEx. How many moles of H2O are produced from 5.0 moles of H2?Balanced Eq: 2H2 + O2 2H2OKnown: 5.0 mol H2, Unknown: mols of H2O= 5.00 mol H2O5.0 mol H22 mol H2O2 mol H2Mole Ratio
6 Page 2- Bottom – Mass to Mole Mole of A to Mass of BMass of A to Mole of BHow many grams of NaCl are produced from 5 moles of Na?Balanced Eq: 2 Na + Cl2 2 NaClKnown: 5 moles of NaUnknown: grams of NaClHow many moles of NaCl are produced from 35 g of Cl2?Balanced Eq: 2 Na + Cl2 2 NaClKnown: 35 g Cl2Unknown: moles NaCl5 mol Na2 mol NaCl58.44 g NaCl35 g Cl21 mole Cl22 mol NaCl2 mol Na1 mol NaCl70.90 g Cl21 mole Cl2Mole Ratio= 0.99 mol NaCl= g NaCl
7 Page 3 – Bottom- Mass to Mass Mass of A to Mass of BEx. How many grams of NO2 are produced from 250 g of N2 gas?Balanced Eq: N2 + 2O2 2NO2Known: 250 g of N2Unknown: grams of NO2= g NO246.01 g NO2250 g N21 mol N22 mol NO228.02 g N21 mol N21 mol NO2Molar MassMole Ratio
8 Page 4 – Bottom – Limiting Reactants Same as all the other problems, you just have to do two of them.If you have 25 g of N2 and 35 g of O2, how many grams of NO2 is produced, which one is the limiting reactant? The excess reactant?Do the problem with N2 first.Balanced Eq: N2 + 2O2 2NO2Known: 25 g N2, Unknown: g NO2= g NO2Now do the same problem with O2Same balanced equationKnown: 35 g O2 ,Unknown: g of NO2= g NO225 g N21 mol N22 mol NO246.01 g NO235 g O21 mol O22 mol NO246.01 NO228.02 g N21 mol N21 mol NO232.00 g O22 mol O21 mol NO250.32 g NO2 is producedNO2 is the excess reactant, it will be left over after the reaction.O2 is the limiting reactant, this reactant will determine how much product is made.
9 Page 5 – Bottom - % YieldDone the same way if you need to figure out the amount of product use the limiting reactant steps.We will use the same balanced equation: N2 + 2O2 2NO2We know that g NO2 is produced.The amount of product you calculate from the limiting reactant problem is the theoretical yield.50.32 g NO2 = theoretical yieldEx. Problem: When this experiment was performed in the lab, the chemist was able to produce g of NO2.48.45 g NO2 = actual yield%Yield = actual yieldX 100theoretical yield% Yield =X 10050.32= 96.3 %