Chemistry 103OutlineMolar Mass from Periodic TableSlide 4The MoleConcept ReviewChemical ReactionChemical’s Shorthand - Chemical RxnBalancing PracticeStoichiometryMoles in EquationsMole to Mole problemsSlide 13Slide 14Reaction InterpretationMoles-to-Grams or Grams-to-MoleChemical StoichiometrySlide 18Slide 19Slide 20Grams-to-Mole“gram to gram” calculationsCalculating the Mass of a ReactantSlide 24Mass calculations“gram to gram” continued….Learning CheckChemical ReactionsLimiting ReactantReacting AmountsReaction EquivalentSlide 32Slide 33Limiting ReactantsChecking CalculationsSlide 36Limiting Reactants Using MassChemistry 103Lecture 15OutlineI. Chemical Reactions - balancing (review)II. Stoichiometry - Limiting ReactantIII. Classification of Reaction TypesMolar Mass from Periodic TableMolar mass •Is the atomic mass expressed in gramsAvogadro’s NumberSolution = 6.022 x 1023Avogadro’s number is equal to 1 moleMakes working with large numbers easierThe Mole Molar mass 1 mole 6.022 x 1023 Mass in grams Individual particlesConcept ReviewDo 7.0g of CO and 7.5 g of C2H6 contain the same number of C atoms? (Prove your answer mathematically)A. YES B. NOChemical ReactionIn a chemical reaction,Old bonds are broken and new bonds are formed Atoms in the reactants are rearranged to form one or more different substancesFe and O2 form rust (Fe2O3)Chemical’s Shorthand - Chemical RxnFe (s) + O2(g) --------> Fe2O3 (s)2Fe(s) + O2(g) --------> Fe2O3(s)4Fe(s) + O2(g) --------> 2Fe2O3(s)4Fe(s) + 3O2(g) --------> 2Fe2O3(s)BALANCED!!!!!Balancing Practice Li3N(s) -------> Li(s) + N2(g) Mg + H3PO4 ------> Mg3(PO4)2 + H2 MgCl2 + AgNO3 ------> Mg(NO3)2 + AgClStoichiometryChemical Stoichiometry: using mass and quantity relationships among reactants and products in a chemical reaction to make predictions about how much product will be made.We can read the equation in “moles” by placing the word “mole” or “mol” between each coefficient and formula.4Fe(s) + 3O2(g) 2Fe2O3(s)4 mol Fe + 3 mol O2 2 mol Fe2O3 Moles in EquationsMole to Mole problemsUsing the balanced chemical reaction, how many moles of O2 will react with 4.28 moles of CS2 to produce CO2 and SO2? CS2 + O2 ------> CO2 + SO2 (unbalanced)Mole to Mole problemsWhen 4.28 moles of CS2 reacts according to the balanced chemical equation below, how many moles of CO2 will be produced? CS2 + 3O2 ------> CO2 + 2SO2Mole to Mole problemsWhen 4.28 moles of CS2 reacts according to the balanced chemical equation below, how many moles of SO2 will be produced? CS2 + 3O2 ------> CO2 + 2SO2Reaction InterpretationUsing the balanced chemical reaction, how many moles of O2 will react with 4.28 moles of CS2 to produce CO2 and SO2? CS2 + 3O2 ------> CO2 + 2SO2BEFOREAFTERMoles-to-Grams or Grams-to-MoleChemical Stoichiometry2H2 + O2 ----> 2H2Omole to mole comparisons: How many moles of O2 are needed to produce 1.39 moles of H2O?Chemical Stoichiometry2H2 + O2 ----> 2H2Omole to gram or gram to mole comparisons:How many moles of O2 are needed to produce 7.4g of H2O?Chemical Stoichiometry2H2 + O2 ----> 2H2Omole to mole comparisons: How many moles of O2 are needed to exactly react with 4.28 moles of H2?Chemical Stoichiometry2H2 + O2 ----> 2H2Omole to gram or gram to mole comparisons:How many moles of O2 are needed to exactly react with 12.4g of H2?How many grams of O2 are needed to produce 0.400 mol Fe2O3?4Fe(s) + 3O2(g) 2 Fe2O3(s)A) 38.4 g O2B) 19.2 g O2 C) 1.90 g O2Grams-to-Mole“gram to gram” calculationsThe reaction between H2 and O2 produces 13.1 g water. How many grams of O2 reacted?2H2(g) + O2(g) 2H2O(g) Plan: g H2O mole H2O mole O2 g O2Calculating the Mass of a ReactantThe reaction between H2 and O2 produces 13.1 g water. How many grams of O2 reacted?2H2(g) + O2(g) 2H2O(g) Before: x g After: 13.1 gPlan: g H2O mole H2O mole O2 g O2Calculating the Mass of a ReactantMass calculationsHow many grams of CS2 are needed to completely react with 6.0g of O2 according to the following reaction?CS2 + 3O2 ------> CO2 + 2SO2“gram to gram” continued….One way to remove gaseous carbon dioxide from the air in a spacecraft is to let canisters of solid lithium hydroxide absorb it according to the following reaction: 2LiOH(s) + CO2(g) ------> Li2CO3(s) + H2O(l)How many grams of LiOH must be used to produce 10.0g of Li2CO3?Learning CheckAcetylene gas C2H2 burns in the oxyacetylene torch for welding. How many grams of C2H2 are burned if the reaction produces 75.0 g CO2? 2C2H2(g) + 5O2(g) 4CO2(g) + 2H2O(g)A) 88.6 g C2H2B) 44.3 g C2H2C) 22.2 g C2H2Chemical ReactionsLimiting Reactant &Percent YieldLimiting ReactantA limiting reactant in a chemical reaction is thesubstance that: •Is used up first•Stops the reaction•Limits the amount of product that can formReacting AmountsIn a table setting, there is 1plate, 1 fork, 1 knife, and 1 spoon.How many table settings arepossible from 5 plates, 6 forks, 4spoons, and 7 knives?What is the limiting item?Reaction Equivalent 1plate + 1fork + 1knife + 1spoon ----> 1place settingBEFORE 5 6 7 4 0AFTER 1 2 3 0 4 LRReacting AmountsIn a table setting, there is 1plate, 2 forks, 1 knife, and 1spoon.How many table settings arepossible from 5 plates, 6 forks, 4spoons, and 7 knives?What is the limiting item?Reaction Equivalent 1plate + 2fork + 1knife + 1spoon ----> 1place settingBEFORE 5 6 7 4 0AFTER 2 0 4 1 3 LRLimiting ReactantsWhen 4.00 mol H2 is mixed with 2.00 mol Cl2,how many moles of HCl can form? H2(g) + Cl2(g)  2HCl (g) 4.00 mol 2.00 mol ??? MolSTEPS:•Calculate the moles of product from each reactant, H2 and Cl2.•The limiting reactant is the one that produces the smallest amount of product.Checking CalculationsInitially H2 4.00 molCl2 2.00 mol2HCl 0 molReacted/Formed-2.00 mol -2.00 mol +4.00 molLeft after reaction 2.00 mol Excess 0 mol Limiting 4.00 molLimiting ReactantIf 4.80 grams Ca mixed with 2.00 grams N2, which is the