2Inquiry ActivityUsing 20 white balls (H), make 10 diatomic molecules. Make diatomic molecules using the yellow balls as well.Without looking, have someone choose 10 molecules at random.Out of the chosen molecules, pair up the reactants using the following chemical equation: Y W2 2YW3Pair up reactants until you run out of one of the reactants. This is your limiting reagent.Repeat the activity and see if you get the same results
3Review – Balance these equations N2 + H2 NH3H2S O2 SO H2OH I2 HI
4StoichiometryStudy of the amount of substances consumed or produced in a chemical reaction– Requires Balanced Equations!Reactants Products
5Reactants and Products Reactants and Products SOMETIMES the same StoichiometryReactants and ProductsALWAYS the sameReactants and Products SOMETIMES the sameNumber of AtomsMassNumber of moleculesMolesVolumeN H2 NH3Atoms N H = N HMass 28g g = gNumber ofmolecules 1 molecule molecules moleculesMoles 1mole moles molesVolume L L L
6What is conserved in each reaction. Atoms. Mass. Number of Molecules What is conserved in each reaction? Atoms? Mass? Number of Molecules? Moles?H O2 H2OH I2 2HIC2H2 + O2 CO2 + H2O
7CalculationsMole ratio: Conversion factor using the coefficients of balanced chemical equationsUsed to convert between moles of reactant and moles of productN H2 2NH31 mol 3 mol 2molSo…..1 mol N2 2 mol NH3 3mol H23 mol H2 1 mol N2 2 mol NH3
8How many moles of ammonia (NH3) are produced when 0 How many moles of ammonia (NH3) are produced when 0.6mol nitrogen (N2) reacts with hydrogen (H2)?Write the chemical reaction:What conversion do you use to get from N2 to NH3?Solve
9Al O2 Al2O3How many moles of aluminum are needed to form 3.7mol of aluminum oxide?How many moles of oxygen are required to react completely with 14.8mol Al?How many moles of Al2O3 are formed when 0.78 mol O2 reacts with aluminum?
10Mole – Mass Calculations Calculate the number of grams of NH3 produced by the reaction of 5.40g hydrogen with an excess of nitrogen.What is the chemical reaction?Conversiongram hydrogen mol hydrogen mol NH3 gram NH3
11CaC H2O C2H Ca(OH)2How many grams of acetylene gas (C2H2) are produced by adding water to 5.00g CaC2?How many moles of CaC2 are needed to react completely with 49.0g H2O?
12ALYWAYS CONVERT THROUGH USING MOLES!!! Other conversions…Number of particles mol6.02x1023 particlesVolume of gas at STP mol22.4LSo you should be able to convert:mass-mass mol-molmass-mol mol-number of particlesmol-volume of gas at STPALYWAYS CONVERT THROUGH USING MOLES!!!
13How many molecules of oxygen are produced when 29 How many molecules of oxygen are produced when 29.2g of water is decomposed? H2O H O2How many grams of nitrogen dioxide must react with water to produce 5.0x1022 molecules of nitrogen monoxide?NO H2O HNO NO
14How many liters of nitrogen dioxide are produced when 34L of oxygen reacts with excess nitrogen monoxide?NO O2 NO2
15How much do you actually get? In any reaction, the amount of product formed is limited by the amount of reagents….Limiting Reagent: -determines the amount of product that can be formed-is completely used up in the reactionExcess Reagent: reactant is not completely used up
16What is the limiting reagent when 80g of Cu reacts with 25g of S in the following reaction? Cu S Cu2SBalance the equationConvert grams to molesWhat is the mole ratio between Cu and S?Take the given mole quantity for one reagent (#2), multiply it by the mole ratio (#3) to find how many moles of the other reagent are neededCompare moles needed to moles you have to find which one is limiting
17What is the limiting reagent if 6.0g HCl reacts with 5.0g Mg? If 2.70mol of C2H4 is reacted with 6.30mol O2, what is the limiting reagent?C2H O2 CO H2OWhat is the limiting reagent if 6.0g HCl reacts with 5.0g Mg?Mg + HCl MgCl H2
18Limiting reagents can be used to find out how much product is actually made. What is the maximum number of grams of Cu2S that can be formed when 80.0 g Cu reacts with 25.0g S?Cu S Cu2SWhat is the limiting reagent?Use the limiting reagent to calculate the amount of product
19How many grams of water can be produced by the reaction of 2 How many grams of water can be produced by the reaction of 2.40mol C2H2 with 7.4mol O2?C2H2 + O2 CO H2OIf 2.7mol C2H4 is reacted with 6.3mol O2, how many moles of water are produced?C2H O2 CO H2O
20Things happen in lab…Theoretical yield: the maximum amount of product that could be formedActual yield: the amount of product that is actually formed in labPercent Yield = Actual yield x 100%Theoretical yield
21What is the percent yield if 13. 1g CaO is actually produced when 24 What is the percent yield if 13.1g CaO is actually produced when 24.8g CaCO3 is heated?CaCO3 CaO + CO2