Chapter 4: Chemical Quantities And Aqueous Reactions
Chemistry 1A: Chapter 4Page 1Chapter 4: Chemical Quantities and Aqueous Reactions:Homework: Read Chapters 4. Work out sample/practice exercisesKeep up with assignments in LabCheck MasteringChemistry.com assignment and complete before due dateReaction Stoichiometry: Chemical arithmetic.Stoichiometry is the study ofnumerical relationships between chemical quantities in a chemical reaction. Using ratiosfound in balanced chemical reactions to solve quantitative problems.Convert to moles, mole to mole ratio, convert to desired result.Practice:1.a)Balance the following unbalanced equation:BaO (s) b)2.HCl (aq) BaCl2 (aq) H2O (l)There are 2 moles of BaO and 2 moles of HCl, which is the limiting reactant?Balance the equation below and calculate the mass in grams of water vaporproduced when 56.0 g of pure hydrogen gas burns in an unlimited supply of oxygen.H2 (g) O2 (g) H2O (g)
Chemistry 1A: Chapter 43.Page 2How many mg of solid iron (III) chloride (FeCl3) result when 15.5 milligrams ofsolid iron (Fe) is reacted with an excess of chlorine gas (Cl 2). Start by balancing theequation.Yields:Actual or Experimental Yield that produced in a lab environment.Theoretical Yield the highest (maximum) possible yield assuming 100%perfection using up all of the limiting reactant.Percent Yield π΄ππ‘π’ππ οΏ½πππ πππππx 100%Limiting reactants:The limiting reactant is completely consumed producing the least amount ofproduct. It runs out first and limits the amount of product.It produces the lowest (maximum) theoretical yield. Limiting reactantproblems occur when two values for reactants are given.Excess reactants:Excess reactants are not completely consumed in the reaction.Practice:4.a)Balance the following unbalanced equation:Ca (s) b)c)d)H2O (l) Ca(OH)2 (aq) H2 (g)How many grams of H2O would be required to react with 8.00 g of calcium?Solve for the theoretical mass of hydrogen gas produced.When the reaction described above was carried out in the lab, 0.346 grams ofhydrogen gas was obtained. Calculate the percent yield for this reaction.
Chemistry 1A: Chapter 45.a)Balance the following unbalanced equation:P4 (s)b)c)d)Page 3 F2 (g) PF5 (g)Calculate the theoretical mass in grams of phosphorus pentafluorideproduced from12.6 grams F2 and 9.00 g phosphorus.What is the limiting reactant from the reaction above?What is the % yield of the reaction above if 15.8g of PF 5 were experimentallyproduced in a lab starting with the given amounts above?Solution Concentrations:Homogenous mixtures are called solutions. The major component that keeps itssame state is called the solvent. The minor component, the one that may have achange in state, is the solute.Dilute solutions have a small amount of solute, concentrated solutions have a largeamount of solute compared to the solvent.Molarity (moles of solute)/(liter of solution)Molarity can be used as a conversion factor to solve for moles instoichiometry problemsSolution Dilution: M1V1 M2V2When diluting solutions it is best to use a volumetric flask and safest tostart with some solvent, then add the concentrated amount, followed bymore solvent to reach the desired total volume.Note: Volumes are not always additive: for example 50 ml of waterplus 50 ml of ethanol only produce 95 ml volume total due to somedifferences in density and intermolecular attractionsOther concentrations for solutions include: mass percent, volume percent,mass/volume percent, ppm, ppb, normality, molality, mole fraction.
Chemistry 1A: Chapter 4Page 4Practice:6.Calculate the Molarity of a solution made from 30.0 grams of sucrose (C12H22O11)added to enough water to make 300 ml total solution.7.Describe quantitatively and qualitatively how one should safely prepare 600 ml of1.0 M H2SO4 (aq) solution from 18.0 M H2SO4 stock solution.8.How many grams of hydrogen gas will be theoretically formed by the reaction of10.0 ml of 6.00 M HCl with excess zinc?Zn (s) HCl (aq) ZnCl2 (aq) H2 (g) unbalanced
Chemistry 1A: Chapter 4Page 5Titrations:In a titration, a substance in a solution of known concentration is reacted withanother of unknown concentration. A burette is used to add a known volume to aflask with an indicator that will change (endpoint) when the reactants reach theirstoichiometric ratio (equivalence point).Practice:9.Solve for the molarity concentration in a 10.0 ml portion of acetic acid solution(HC2H3O2) that required 39.6 ml of 0.202 M NaOH solution to reach theequivalence point in a titration.
Chemistry 1A: Chapter 4Page 6Gas Stoichiometry:Molar volume at STP for any ideal gas is 22.4 L/molSTP standard temperature (0 C) and pressure (1 atmosphere)Practice:10. Pure iron may be prepared from iron(III) oxide and carbon monoxide:Fe2O3 (s) CO (g) Fe (s) CO2 (g)a) Balance the unbalanced equation above.b) Calculate the maximum theoretical mass in grams of Fe produced from 40.0 Lof carbon monoxide at STP from the reaction above.Dissolving a SoluteWhen mixing a solute with the solvent, attractions between the like substances mustbreak while attractions between solute-solvent are formed. If the new solute-solventattractions are strong enough, the solute will dissolve.Water is a polar molecule withuneven distribution ofelectrons: (more on the oxygen -, less on the hydrogen )When ionic compoundsdissolve in water, each ion isattracted to the polar water andsurrounded by a solvent cage ofwater. The result is a solutionwith free moving chargedparticles that may conductelectricity.Materials that dissolve in water to form a solution that will conduct electricity arecalled electrolytes.
Chemistry 1A: Chapter 4Page 7Electrolytes in Aqueous Solution:Strong Electrolytes will largely dissociate into its ions in an aqueous solution andare written as separated ions in the ionic reactions.Examples: Strong acids, Strong Bases, Soluble salts.Strong Acids: HCl, HBr, HI, HNO3, H2SO4, HClO4, HClO3Strong Bases: soluble hydroxides from Group 1A (not including H)and Group 11A, not including the top two) LiOH, NaOH, KOH,RbOH, Ca(OH)2, Sr(OH)2, Ba(OH)2Soluble Salts: Ionic compounds that contain the cations from Group1A; Li , Na , K , Rb , Cs , or ammonium ion, NH4 . A compound isprobably soluble if it has the anion; Cl-1, Br-1, I-1 except with Ag ,Hg2 2, or Pb 2, and most compounds that include NO3-1, ClO4-1,C2H3O2-1, Soluble with most SO4-2 except Ba 2, Hg2 2, or Pb 2.Weak Electrolytes will partially dissociate into its ions in an aqueous solution, butare written as compounds in an ionic equation. Weak electrolytes are the weakacids and weak bases such as HC2H3O2 or NH3Nonelectrolytes will stay in their formula in an aqueous solution. Nonelectrolytesare the insoluble salts, gases, liquids, and other solids.Writing Molecular, Ionic, and Net ionic equations:Example: For the double displacement reaction of lead (II) nitrate reactingwith aluminum chloride.Whole equation: UnbalancedPb(NO3)2 (aq) AlCl3 (aq) PbCl2 (s) Al(NO3)3 (aq)Total ionic equation: UnbalancedPb 2(aq) NO3-1(aq) Al 3(aq) Cl-1(aq) PbCl2 (s) Al 3(aq) NO3-1(aq)Identify the spectator ions and leave them out when writing the net ionic eq.Net ionic equation: UnbalancedPb 2 (aq) Cl-1 (aq) PbCl2 (s)
Chemistry 1A: Chapter 4Page 8Chemical Reactions:Evidence of chemical reactions:Examples formation of a solid, or formation of gas, light given off, change intemperature, etc.Driving forces of chemical reactions:1)Transfer of electrons occurs in redox (oxidation-reduction) reactions2)Formation of solid3)Formation of gas4)Formation of water or a weak electrolyte (weak acid or weak base)5)Other driving forces not listed may occurClassifying Chemical Reactions:Types of Chemical Reactions:(D-D) double displacement: AB CD AD CB(P) precipitation: a solid is formed(N) neutralization or acid-base: water is formed(G) gas evolution: gas is formed(Syn) synthesis or combination: A B AB(D) decomposition: AB A B(R) redox or oxidation-reduction: electrons are transferred(C) combustion: add O2 gas, possible products include: CO2, H2O, NO2, SO2.(SR) single replacement: A BC AC B or BA CThe more active metal will have a partner, less active is alone.Activity series: Au Hg Ag Cu H2 Pb Sn Ni Cd Fe Cr Zn Mn Al Mg Na Ca K Li
Chemistry 1A: Chapter 4Page 9Classifying and Predicting Products and Chemical Reactions:The following examples will help you classify the type of reaction and predict theexpected products. Refer to the solubility rules to determine if solid forms.(D-D) double displacement: AB CD AD CBA double displacement reaction starts with two ionic compounds in which the ionsexchange to produce new balanced ionic compounds. Always write the cationbefore the anion and verify that the net charge of a compound is zero. Ioniccompounds may be acid, base, or salt. Oxidation charges do not alter in doubledisplacement reactions so this type will never be a redox reaction.(NR) When all ionic products are strong electrolytes, there is NO REACTION.FeBr3 (aq) 3 LiNO3 (aq) 3LiBr (aq) Fe(NO3)3 (aq)NRDriving forces for double displacement reactions include (P) Precipitation, formation of solid(N) Neutralization or Acid-Base Reaction, formation of water(G) gas evolution, formation of a gas(WE) formation of a weak electrolyte, a soluble weak acid or weak base(P)Formation of a new solid in a double displacement reaction when there isno solid on the reactant side is called PRECIPITATION.Ni(NO3)2 (aq) Na2S (aq)(N) NiS (s) 2 NaNO3 (aq)DD,PFormation of water in a double displacement reaction is calledNEUTRALIZATION (also known as Acid-Base reaction)3 KOH (aq) H3PO4(aq) K3PO4 (aq) 3 H2O (l)DD,N(WE) Formation of a WEAK ELECTROLYTE, generally a weak acid, producedfrom a double displacement reactionAl(C2H3O2)3 (aq) 3 HCl (aq) AlCl3 (aq) 3 HC2H3O2 (aq)DD,WE(G) Gas Evolution:Several common products are in the gas phase. You should recognize the followingas gas products.CO2, SO2, NH3, H2S, H2, N2, O2, F2, Cl2, NO2
Chemistry 1A: Chapter 4P a g e 10Special cases of (G) Gas Evolution in (DD) Double Displacement:There are three common products that further decompose leading to three productsin place of just the two products in a double displacement reaction. They are asfollows.NH4OH (aq) NH3 (g) H2O (l)H2SO3 (aq) SO2 (g) H2O (l)H2CO3 (aq) CO2 (g) H2O (l)The double displacement reactions below show examples of the decomposition ofone of the ionic products. The driving forces include both formation of water and agas, because water is formed these can be labeled DD, N, G reactions. The last oneis DD, N, G and P.K2CO3 (aq) 2HCl (aq) H2CO3 (aq) 2 KCl (aq)K2CO3 (aq) 2HCl (aq) CO2 (g) H2O (l) 2 KCl (aq)Na2SO3 (aq) 2HCl (aq) H2SO3 (aq) 2 NaCl (aq)Na2SO3 (aq) 2HCl (aq) SO2 (g) H2O (l) 2 NaCl (aq)(NH4)2SO4 (aq) Ba(OH)2 (aq) 2 NH4OH (aq) BaSO4 (s)(NH4)2SO4 (aq) Ba(OH)2 (aq) 2 NH3 (g) 2 H2O (l) BaSO4 (s)(Syn) Synthesis or combination: A B ABA synthesis reaction starts with two or more substances and creates a singlecompound product. The reverse of a synthesis reaction is Decomposition.Remember which elements are diatomic elements: H2, N2, O2, F2, Cl2, Br2, I2. Knowthe elements in their pure form: gas, solid, and liquid.a) two elements (metal plus nonmetal) ionic compound.K (s) Cl2 (g) KCl (s)b) metal oxide and water base (metal hydroxide)BaO (g) H2O (l) Ba(OH)2 (aq)c) nonmetal oxide and water acidCO2 (g) H2O (l) H2CO3 (aq)
Chemistry 1A: Chapter 4P a g e 11(D) Decomposition: AB A BA decomposition reaction starts with one reactant and breaks up into two or moresubstances. The reverse of a decomposition reaction is synthesis. Remember thediatomic elements: H2, N2, O2, F2, Cl2, Br2, I2.a) ionic compound two elements (metal plus nonmetal)2 Fe2O3 (s) 4 Fe (s) 3 O2 (g)b) metal carbonate metal oxide and carbon dioxideCaCO3 (s) CaO (s) CO2 (g)c) metal bicarbonate metal carbonate water carbon dioxide2 Al(HCO3)3 (s) Al2(CO3)3 (s) 3 H2O (l) 3 CO2 (g)d) metal connected to halogen with oxygen metal halide oxygenCa(BrO3)2 (s) CaBr2 (s) 3 O2 (g)e) hydrated salt anhydrous salt plus waterCuSO4.5H2O (s) CuSO4 (s) 5 H2O (l)(R) Redox or oxidation-reduction:Redox reactions have a transfer of electrons. An easy what to tell that a redoxreaction takes place is to check for element charges and see if they change fromreactant to product. Some synthesis and decomposition reactions are redox such asthe synthesis (a), and decomposition (a), (d) reactions. All single replacement andcombustion reactions are redox reactions.(C) Combustion: elements burn with O2 gas to produce oxides,Common products include: CO2, H2O, NO2, SO2.NH3 (g) O2 (g) C4H10 (s) O2 (g) C17H24S (s) O2 (g) C12H22O11 (s) O2 (g) (SR) Single Replacement: A BC AC B or BA CThe more active metal will have a partner, less active is alone.Activity series: Au Hg Ag Cu H2 Pb Sn Ni Cd Fe Cr Zn Mn Al Mg Na Ca K LiDo NOT memorize the activity series. The necessary information will begiven to you as needed. Most of the transition metals commonly have a 2charge, except Ag 1, Cr 3, and Au 3
Chemistry 1A: Chapter 4P a g e 12Predict the products if a reaction occurs or write NR for no reaction Zn(NO3)2 (aq) Cu (s) Cu(NO3)2 (aq) Ag (s) AgNO3 (aq) Cu (s) The nonmetal activity levels increase as you go from the bottom to the top of the periodictable:Given that F Cl Br I. Predict the products or write NR NaBr (s) Cl2 (g) NaBr (s) I2 (s) Redox Reactions:Redox reactions exchange electrons. When balancing a reaction (1) electrons lost electrons gained(2) atoms on either side of the reaction must balance(3) total charge on either side of the reaction must balance.Oxidationincreases oxidation numberlose electrons2 Cl-1 Cl2 2 eCl-1 is oxidizedCl-1 is a reducing agentReductionreduces oxidation numbergain electronsK 1 e- KK is reducedK is an oxidizing agentRules for Assigning Oxidation Numbers1)elementszero2)monatomic ionscharge on ion3)oxygenmostly (-2)Exceptions:peroxide, O2-2, (-1) andsuperoxides, O2-1, (-1/2)4)hydrogenmostly ( 1)exceptions:hydrides (-1)5)halogensmostly (-1)Exceptions: ( 1, 3, 5, 7)in a compound with lighter halogens or oxygen6)Compoundssum of oxidation numbers equal zero7)polyatomic ionssum of oxidation numbers equal charge of ion
Chemistry 1A: Chapter 4P a g e 13Balancing Complicated Redox Rxns using the Half Rxn Method (Ch 18):The half reaction method of balancing for the electrochemistry reactions splits apartthe oxidation half reaction from the reduction half reaction and then adds the twotogether for an overall reaction.1)Assign oxidation numbers to each atom.2)Determine what is being oxidized and what is reduced.3)Split the skeleton equation into two half reactions label appropriately as oxidationor reduction reactions.4)Complete and balance each half reaction (This method does not need to use theoxidation numbers)a)balance atoms that change their oxidation numbersb)balance O by adding H2Oc)balance H by adding H d)balance charges by including the electrons as products in the oxidationreaction and electrons as reactants in the reduction reactione)If the solution is basic: add equal OH-1 ions on both sides of the equation tocounter all H ions, every H and OH-1 become H2O essentially removing allH ions from the reaction.5)Combine the two half reactions to obtain overall equationa)Multiply each half reaction by the factor needed tohave equivalentelectrons lost and gained.b)Simplify and reduce to the lowest whole number ratio6)Check balancinga)Do atoms balance?b)Are the sum of charges of reactants equal to those of products?c)Are the same number on electrons lost and gained?Redox: Balance the following.a) Al (s) SO4-2 (aq) Al 3 (aq) SO2 (g)(acidic conditions)b) A breathalyzer detects ethanol in suspected drunk drivers using the reaction belowCr2O7-2 (aq) C2H5OH (l) Cr 3 (aq) C2H4O (l) (acidic conditions)
Chemistry 1A: Chapter 4c) MnO4d) MnO4e) Br 2-1-1P a g e 14 2 MnO2-1 Mn Mn IO3 BrO 3-1 2(acidic conditions) BrIO4-1-1(basic conditions)(basic conditions)Redox Applications: Combustion, Bleaching, Batteries, Metallurgy, Corrosion,Respiration, TitrationRedox Titration: Electrons transfer. Titrate with burette as liquid is slowly addedto a flask. Color changes to indicate endpoint just like acid/base titrations.Example :The indicator, MnO4-1 has an intense dark purple color. For the example below,MnO4-1 is a dark purple reactant in the burette. It will colorlessly react with oxalicacid in the flask until the oxalic acid runs out. At the endpoint, excess MnO4-1 turnsthe flask solution purple.Calcium levels in blood may be determined by adding oxalate ion to precipitate thecalcium oxalate, CaC2O4 Ca 2(in blood) C2O4-2 CaC2O4 (s) (solid is separated out of the blood)followed by dissolving the precipitate in acid CaC2O4 (s) 2H 1 (aq) H2C2O4 (aq) Ca 2and titrating the resulting oxalic acid with KMnO4 (K is a spectator ion which isleft out of the reaction.)5H2C2O4 (aq) 2MnO4-1(aq) 6H 1(aq) 10CO2(g) 2Mn 2(aq) 8H2O(l)How many milligrams of Ca 2 are present in 10.0 ml of blood if 21.08 ml of0.00988M KMnO4 solution is needed?
Chemistry 1A: Chapter 4P a g e 15Memorize the Soluble Solubility Rules:Compounds containing these ions are Exceptions: (when combined withgenerally solubleions on left, compound is insoluble)Li , Na , K , NH4 noneNO3-, C2H3O2-noneCl-, Br-, I-Ag , Hg2 2, Pb 2SO4-2Ag , Ca 2, Sr 2, Ba 2, Pb 2Be able to use the Insoluble Solubility Rules:Compounds containing these ions are Exceptions: (when combined with ionson left, compound is soluble or slightlygenerally insolublesolubleOH-Li , Na , K , NH4 Ca 2, Sr 2, Ba 2S-2Li , Na , K , NH4 , Ca 2, Sr 2, Ba 2CO3-2, PO4-3Li , Na , K , NH4 Practice:11. List elements that are diatomic.12. Name several driving forces for a chemical reaction.13. Name several signs of evidence that would indicate a chemical reaction happened.14. What information can one obtain from a balanced chemical equation?15. a)Complete and balance the double-displacement whole equation.Include the physical states.Na2SO4 (aq) AgNO3 (aq) b)Write the balanced total ionic equation for the above reaction. Includecharges on ions and physical states. Circle the spectator ions.c)Write the balanced net ionic equation for this reaction.d)What is/are the driving force(s) for this reaction?
Chemistry 1A: Chapter 4P a g e 1616. Crude gunpowders often contain a mixture of solid potassium nitrate and charcoal(solid carbon). When such a mixture is heated until a reaction occurs, a solidresidue of potassium carbonate is produced. The explosive force of thegunpowder comes from the fact that two gases are also produced, carbon monoxideand nitrogen, which increase in volume with great force and speed. Write thebalanced chemical equation for the reaction.17. Balance and Classify in as many ways possible the following reactions.Possible classifications:(R) redox or oxidation-reduction(D) decomposition(N) neutralization(C) combustion(G) gas evolution(D-D) double displacement(SR) single replacement(Syn)synthesis or combination(P) precipitationa)NaI (s) F2 (g) b)NH3 (g) c)N2 (g) d)C4H10 (l) O2 (g)e)As(OH)3 (aq) H2SO4(aq) As2(SO4)3(aq)f)aqueous silver nitrate and solid copper reacts to form aqueous copper (II)nitrate and solid silver.g)solid magnesium chlorate heated produces oxygen gas and solid magnesiumchlorideNaF (s) I2 (s)O2 (g) O2 (g) NO2 (g) H2O (l)N2O5 (g) CO2 (g) H2O (g) H2O (l)
Chemistry 1A: Chapter 4P a g e 17h)A chemical process that uses electricity is called an electrolysis reaction.When an electrical current passes through a concentrated aqueous sodiumchloride solution, several useful products can be isolated: aqueous sodiumhydroxide, chlorine gas, and hydrogen gas. Write the balanced chemicalequation for this process.i)Fe (s)j)
Classifying and Predicting Products and Chemical Reactions: The following examples will help you classify the type of reaction and predict the expected products.
Part One: Heir of Ash Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26 Chapter 27 Chapter 28 Chapter 29 Chapter 30 .
TO KILL A MOCKINGBIRD. Contents Dedication Epigraph Part One Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Part Two Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18. Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26
DEDICATION PART ONE Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 PART TWO Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 .
made in a chemical reaction is related to the amounts of all the other substances in the reaction. β Law of conservation of mass β Balancing equations by balancing atoms The study of the numerical relationship between chemical quantities in a chemical reaction is called stoichiometry. Quantities in Chemical Reactions
Chemical Formulas and Equations continued How Are Chemical Formulas Used to Write Chemical Equations? Scientists use chemical equations to describe reac-tions. A chemical equation uses chemical symbols and formulas as a short way to show what happens in a chemical reaction. A chemical equation shows that atoms are only rearranged in a chemical .
Levenspiel (2004, p. iii) has given a concise and apt description of chemical reaction engineering (CRE): Chemical reaction engineering is that engineering activity concerned with the ex-ploitation of chemical reactions on a commercial scale. Its goal is the successful design and operation of chemical reactors, and probably more than any other ac-File Size: 344KBPage Count: 56Explore further(PDF) Chemical Reaction Engineering, 3rd Edition by Octave .www.academia.edu(PDF) Elements of Chemical Reaction Engineering Fifth .www.academia.eduIntroduction to Chemical Engineering: Chemical Reaction .ethz.chFundamentals of Chemical Reactor Theory1www.seas.ucla.eduRecommended to you b
single real number, these quantities are often called scalars. Other quantities, such as directed distances, velocities and forces , require for their complete specification both a magnitude and direction, these quantities are called vectors. Vectors
Page 1 Unit 1: Relationships Between Quantities UNIT 1: RELATIONSHIPS BETWEEN QUANTITIES Quantities and Units MGSE9-12.N.Q.1 Use units of measure (linear, area, capacity, rates, and time) as a way to understand problems. MGSE9-12.N.Q.2 Define appropriate quantities for the purpose of descriptive modeling.
