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MOLECULAR FORMULA B24W8 MM 56 1 1 M O L E C U L E M O L E C U L E EMPIRICAL FORMULA B3W1 MM 7 The main tasks of Chap Balance Equations—easiest 8 M A N Y M A N Y M O L E C U L E S M O L E C U L E S Balancing equations CH4 + O2 → CO2 + 2 H2 O A + sign shows that the compounds combine form the products on the right of the arrow. The arrow is read as “reacts to yield” Example Classify Equations—easy Methane and oxygen = Combustion Predicting reactions from word problems – challenging C (s) + O2 (g) CO2 (g) Carbon (solid) reacts with diatomic oxygen (gas) to yield carbon dioxide (gas) Methane + Oxygen → Total Ionic Equations--challenging + - + - Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq ) - + AgCl (s) + NO3 (aq) + Na (aq) When balancing a chemical reaction you may An equation is balanced when total number of atoms of each element occur 1. the same number of times 2. on both sides of the equation. Law of conservation of mass. add coefficients in front of the compounds to balance the reaction, you may not change the subscripts. Changing the subscripts changes the compound. 1 Symbols of Conditions Solid (s) gas (g) Liquid (l ) Aqueous solution (aq) Change of temperature (∆) Produces, Yields ( ) Reversible Reaction ( ) Compound above arrow: catalyst 4 basic steps to balancing A coefficient in front of a formula multiplies everything in the formula by that number. 2H2O 1. Write the unbalanced formula 2. Count up atoms on both sides 3. Pick an unequal element and increase the coefficient on the smaller side 4. Repeat step 3 until all atoms are equal on each side of equation 4NaOH 4 Al(s) + 3 O2(g) ---> ---> Al2O3(s) 4 Al(s) + 3 O2(g) ---> 2 Al2O3(s) This equation means 4 Al atoms + 3 O2 molecules ---produces---> 2 molecules of Al2O3 AND/OR 4 moles of Al + 3 moles of O2 ---produces---> 2 moles of Al2O3 2 Write and balance the chemical equation : Carbon Tetrahydride gas (methane) reacts with oxygen gas To yield carbon dioxide gas and liquid water 1) What are the formulas of the reactants and products? Balancing Trick Do Carbon and Others First Do Hydrogen Do Oxygen last REACTANT PRODUCT Methane: CH4 Carbon dioxide: CO2 Oxygen gas: O2 Water: H2 O 2) Write the general formula of the reaction CH4(g) + O2 (g) → CO2 (g) + H2O(l) CH4 (g) + O2 (g) → CO2 (g) + H2 O(l) CH4 (l) + O2 (g) → CO2 (g) + H2 O(l) Count the number of each element on both sides For H: What number do you multiply the 2 H on the product by to equal 4 Hs on the reactant side? 2 CH4 (g) + O2 (g) → CO2 (g) + 2 H2 O(l) ELEMENT REACTANT PRODUCT C H 1 4 1 2 So now there are 4 H’s on both sides Now there are 2 O on the reactant side and 4 O on the product side O 2 3 For O: what number do you multiply the 2O on the reactant side to get 4O? 2 C is balanced H is off by 2 and O is off by 1 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2 O(l) ELEMENT REACTANT PRODUCT C 1 1 H 4 4 O 4 4 Reaction is balanced CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2 O(l) An iron bar rusts. The solid Iron reacts with Oxygen gas (in the air) to make Iron (III) Oxide (rust). If O xy gen is diatomic, What w ill be the ionically bonded formula Fe 3+ + (O 2) = 3+ 2- Fe(s) + O2 (g) → Fe2O3 (s) 3 Fe(s) + O2 (g) → Fe(s) + O2 (g) → Fe2 O3 (s) Fe2O3 (s) For Fe: What number do you multiply the Fe on the reactant side to equal 2 Fe on the product side? 2 Count the number of each element on both sides ELEMENT REACTANT PRODUCT Fe O 1 2 2 3 2Fe(s) + O2 (g) → Fe2 O3 (s) So now there are 2 Fe on both sides Now there are 2 O on the reactant side and 3 O on the product side For O: what number do you multiply the 2 O on the reactant side to get 3 O? 3 Fe is off by 1 and O is off by 1 2Fe(s) + 3O2 (g) → Fe2 O3 (s) HOMEWORK ANSWERS 2Fe(s) + 3O2 (g) → Fe2 O3 (s) For O: what number do you multiply the 3O on the Product side to equal 6O on reactant side? 2 For Fe: what number do you change the 2Fe on the Reactant side to get 4Fe on the product side? 4 4Fe(s) + 3O2 (g) → 2Fe2 O3 (s) ELEMENT REACTANT PRODUCT Fe 4 4 O 6 6 2 Reaction is balanced Balance these skeleton equations: Balance these skeleton equations: a) b) Mg + HCl → MgCl2 + H2 Ca + N2 → Ca3N2 a) b) Mg + 2HCl → MgCl2 + H2 3Ca + N2 → Ca3N2 c) d) e) f) NH4NO3 → N2O + H2O BiCl3 + H2S → Bi2S3 + HCl C4H10 + O2 → CO2 + H2O O2 + C6H12O6 → CO2 + H2O c) d) e) f) NH4NO3 → N2O + 2H2O 2BiCl3 + 3H2S → Bi2S3 + 6HCl 2C4H10 + 13O2 → 8CO2 + 10H2O 6O2 + C6H12O6 → 6CO2 + 6H2O g) h) i) NO2 + H2O → HNO3 + NO Cr 2(SO4) 3+ NaOH → Cr(OH) 3+ Na2SO4 Al4C3 + H2O → CH4 + Al(OH) 3 g) h) i) 3NO2 + H2O → 2HNO3 + NO Cr 2(SO4) 3+ 6NaOH → 2Cr(OH) 3+ 3Na2SO4 Al4C3 + 12H2O → 3CH4 + 4Al(OH) 3 4 Lead (II) Nitrate liquid dissociates when heated to yield Lead (II) Oxide solid, Nitrogen Dioxide gas and Oxygen gas. Pb(NO3)2 → PbO (l ) (s) + NO2 ( g) + O2 Silver Nitrate and Iron (III) Chloride undergo a double displacement reaction. Predict the products and balance the equation. ( g) AgNO3 + FeCl3 → 2Pb(NO3)2 AgCl + Fe(NO3)3 → 2PbO(s) + 4NO2(g) + O2(g) (l ) 3AgNO3 + FeCl3 → 3AgCl + Fe(NO3)3 Types of Reactions There are 6 types of chemical reactions we will talk about: 1. 2. 3. 4. 5. 6. Combustion reactions Synthesis reactions Decomposition reactions Single Displacement reactions Double Displacement reactions Acid Base Reactions (Not In Book) You need to be able to identify the type of reaction study page 284 Combustion Reactions • In general: CxH y + O2 CO2 + H 2O • Products in combustion are ALWAYS carbon dioxide and water. (although inTotal burning does cause some by-products like carbon monoxide) • Combustion is used to heat homes and run automobiles (octane, as in gasoline, is C8H 18) Balance the chemical equation for combustion of pentane 1. Combustion Reactions Combustion reactions occur when a hydrocarbon reacts with oxygen gas. This is also called burning!!! In order to burn something you need the 3 things in the “fire triangle”: 1) A Fuel (hydrocarbon) 2) Oxygen to sustain burn 3) Something to start the reaction (spark) (AKA a catalyst) Example balancing chemical equations Step 1 . Insert 1 in front of the most complicated looking chemical compound. 1 C 5H12 + O2 --> CO2 + H 2O Step 2 . To balance C's, 5 must be inserted in front of C O 2. 1 C 5H12 + O2 --> 5CO2 + H 2O Step 3 . To balance H 's, 6 must be inserted in front of H 2O . 1 C 5H12 + O2 --> 5CO2 + 6 H2O Step 4 . To balance O's, 8 must be inserted in front of O 2 . 1 C 5H12 + 8O2 = 5CO2 + 6H2O E rase 1 from the equation: C 5H 12 + 8O2 = 5CO2 + 6H2O 5 2 The Videos that play with this are found in TheSPEAR (transfer file) 1_24\SHS CHEM\STADIUM CHEM\DEMO Chemystery\Demos Not Used\Chem Comes alive Combustion Reactions Example: The Combustion of Pentane C5H12 C 5H12 + 8 O2 Combustion Reactions The Combustion of Pentyne C5H10 2 C 5H10 + 15 O2 10 5 CO2 +10 5 H2O 5 CO2 + 6 H2O F or O : w hat number do y ou multiply the 15 on the product side to get and even number ( odd even technique)? A n ev en x odd w ill alw ays be even an odd x ev en = even S o multiply the ev en (2) by 15 and the odd (15) x2 and the. C heck y our table to see that all are balanced. F or C and H : G o back and balance C and H . As Long as O does N ot C hange it w ill be balanced as w ell. C heck y our table to see that all are balanced. 6 Combustion Reactions The Combustion of Propane C3H8 C 3H8 +5 O2 3 CO2 + 2. Synthesis Reactions • Synthesis reactions occur when two substances (generally elements) combine and form a compound. 4 H2O reactant + reactant 1 product • Basically: A + B AB • • Example:2 H2 + O2 2 H2O Example: C + O2 CO2 C heck y our table to see that all are balanced. Decomposition Reactions Decomposition Reactions C + O2 2 H2 + O2 CO2 2 H2O 2 C + O2 Synthesis Reactions Solid Potassium reacts with chlorine gas to form solid 2 CO Synthesis Reactions potassium chloride salt. 2 K (s) + Cl2 (g) 2 KCl (s) Reaction of Sulfur + Copper(II) S(s) + Cu(s) CuS(s) 7 Synthesis Reactions JOD The last words of a chemist: 1. First the acid, then the water... 2. And now the detonating gas problem. 3. This is a Totally safe experimental setup. 4. Where did I put my gloves? 5. Oh no, wrong beaker... 6. The fire alarm is just being tested. 7. Now you can take the safety glass away... 8. I can just feel it how long 45 seconds are! 9. Something is wrong here... 10.. Trust me - I know what I am doing. Reaction of Aluminum + Bromine 2 Al(s) + 3 Br 2(l) 2 AlBr 3(s) Synthesis Reactions JOD What type of math does the chemistry owl like to use for balancing formulas? Owlgebra N2 + 4 H2 2 NH4 3. Decomposition Reactions • Decomposition reactions occur when a compound • • • Synthesize Nitrogen Tetrahydride Decomposition Reactions Another view of a decomposition reaction: breaks up into simpler structures Reactant Product + Product AB A + B 8 Decomposition Reactions Decomposition Reactions 2 NI3 2 HgO 2Hg + O2 Decomposition Reactions N2 + 3 I2 4. Single Displacement Reactions • Single Displacement Reactions occur when one element replaces another in a compound. A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-). • element + compound product + product • 2 H2O 2 H2 + O2 A + BC AC + B (if A & B are metals) OR D + BC BD + C (if D& C are nonmetals) (remember the cation always goes first!) Single Displacement Reactions Another view: Single Displacement Reactions Li Sodium chloride solid reacts with fluorine gas SDR 2 NaCl(s) + F2(g) 2 NaF(s) + Cl2(g) Aluminum metal reacts with aqueous copper (II) nitrate SDR 2 Al(s) + 3 Cu(NO3)2(aq) 3 Cu(s) +2 Al(NO3)3(aq) H Lithium metal reacts with Calcium Oxide SDR 2 Li(s) + CaO(s) Li2O(s) + Ca(s) 9 Activity Series The activity series for predicting the products of Metal Displacement (and nonmetal) reactions. Single Replacement Rxns To determine if a Single Replacement Reaction really happens, use the ACTIVITY SERIES reference sheet. If an element is higher on the chart, it will become a compound. If the higher element is already in a compound, then NO reaction occurs Most activ e (most strongly reducing) metals appear on top, least activ e metals appear on the bottom. Li K Ca Na Mg displace H2 from acids only can't displace H2 KOH(aq) + H2(g) Ca(s) + 2 H2O() Ca(OH)2(s) + H2(g) Al 2 Na(s) + 2 H2O() Mn 2 NaOH(aq) + H2(g) 2O(g) Zn displace H2 from steam or acids 2 Li(s) + 2 H2O() 2 LiOH(aq) 2 K(s) + H2(g) + 2 H2O() 2 Fe Ni Li Mg(s) + 2 H 2 Al(s) + +6H2(g) Mg(OH)2(s) H2O(g) 2 Al(OH)3(s) + Mn(s) + 2 H2O(g) The nonmetal activity series. Most active (most strongly oxidizing) nonmetals appear on top, and least active nonmetals appear on the bottom. Cl2 O2 Mn(OH)2(s) + H2(g) 2O(g) Zn(s) + 2 H Br2 Pb Zn(OH)2(s) + H2(g) 2O(g) I2 H2 Fe(OH)2(s) Ni(s) + 2+ H2(g) H+(aq) Cu 2+ Ni (aq) + H2(g) Ag Sn(s) + 2 H+(aq) Pt 2+ Sn (aq) + H2(g) + Au 2Cu+Mg(NO 3) 2 Strongest oxidizing agent F2 Sn Ag + H2O NO RXN Fe(s) + 2 H H Pb(s) + 2 H weakest oxidizing agent S (aq) 2+ Pb (aq) + H2(g) 2HCl + F2 2HF + Cl2 Ag + H2O NO RXN 2Al + MnO Mn + Al2O3 KBr + O2 K2O + Br2 Cu + H2O NO RXN Au + CaO NO RXN Metals with lower ionization energies and lower Electronegativity are more active, they lose electrons more easily. 3 H2(g) E xamples of Reactions That Don’t Work, or Work Mg + 2CuNO 3 A strip of copper placed into a zinc sulfate will not react Single Displacement Reactions Does Carbon Dioxide solid react with Mg? 2 Mg + CO2 → 2 MgO + C Shortcut to MAGCO2.lnk Ag + SnO NO RXN 10 If X- ends in -ide --- acid name becomes HydroX-ic acid HC l HBr HF Hydrobromic Hydrochloric Acid ACID REVIEW HydroFlouric Acid Acid 2. if X- ends in -ate --- acid name becomes acid ( No Hydro-) HNO3 H2SO 4 HC lO 3 Nitric Sulfuric 3. if X- ends Acidin -ite --- acid Acidname becomes ous acid HNO 2 H2SO 3 HC l02 Nitrous Acid Sulfurous Acid X-ic Chloric Acid X- Chlorous Acid ACID NAMING RACE 12)HNO2 Phosphoric Acid Chlorous Acid Nitrous Acid 13)HC2H3O2 15)H3PO3 Acetic Acid Phosphorous Acid 16)H2CrO4 17)HCO3 Chromic Acid Carbonic Acid Hydrosulfic Acid 11)H3PO4 12)HClO2 18) H2S 19) HNO3 20) HI Single Displacement Reactions Sodium SDR with Hydrochloric Acid 2 Na + 2 HCl 2 NaCl + H2 Nitric Acid Hydroiotic Acid Single Displacement Reactions Potassium reacts with nitric acid SDR 2 K + 2 HNO3 2 KNO3 + H2 4. Double Displacement Reactions • Double Displacement Reactions occur when a metal replaces a metal in a compound and a nonmetal replaces a nonmetal in a compound • Compound + compound product + product AB + CD AD + CB Zinc reacts with sulfuric acid SDR Zn + H2SO4 Zn + H2SO4 ? ZnSO4 + H2 11 Double Displacement Reactions • Think about it like “foil” in algebra, first and last ions go together + inside ions go together • Example: Double Displacement Reactions Reaction of Sodium Hydroxide + Cobalt (II) Chloride 2 NaOH (l) + CoCl2 (l) 2 NaCl + Co(OH)2 AgCl(s) + NaNO3(aq) AgNO3(aq) + NaCl(aq) Shortcut to AGNONAOH.lnk • Another example: K2SO4(aq) + Ba(NO3)2(aq) 2 KNO 3(aq) + BaSO 4(s) Double Displacement Reactions Double Displacement Reactions Reaction of Sodium Hydroxide + Silver Nitrate Sodium Iodide with Mercury (II) Chloride 2 AgNO 3(aq) + 2 NaOH(aq) Ag2O(s) + 2 NaNO 3(aq) + H2O(l) HgCl2(aq) + 2 NaI(aq) HgI2(s) + 2 NaCl(aq) Shortcut to Sodium Iodide and HgCl.lnk Shortcut to AGNONAOH.lnk WHAT DO YOU NOTICE IN THESE REACTIONS Single Replacement Rxns To determine if the reaction occurs, use the ACTIVITY SERIES. Double Replacement Rxns Two Ionic Compounds switch partners. are mixed. If the products are both aqueous ionic compounds, then no reaction occurs. 12 How to use Solubility Rules. Soluble = dissolves in water=(aq)=aqueous Insoluble= doesn’t dissolve in water = Solid = (s) = cloudy = precipitate = ppt C— DR—Double Combusion Replacement AB SR SR S DR SR C D S SR—Single Replacement S—Synthesis D—Decomp AB—Acid Base HCl + NaOH → NaCl + H2O ZnS + 2 HCl → ZnCl2 + H2S 2 HCl + Zn → ZnCl2 + H2 2 H2 + O2 → 2 H2O 3 Ca(OH)2 + 2 H3PO4 → Ca3(PO4)2 + 6 H2O 8 Al + 3 Fe3O4 → 4 Al2O3 + 9 Fe C5H12 + 8 O2 → 5 CO 2 + 6 H2O 2 H2O2 → 2 H2O + O2 CaO + CO2 → CaCO3 Solubility Rules: see Table p 288 HOW DO WE KNOW (s) In A queous Solution (AKA Water) : A ll compounds of Group 1 and NH4+ are soluble. A ll nitrates are soluble. A ll halogens , except those of Ag+ and Pb 2 + are soluble. A ll sulfates, except those of Group 2, Ag+, and Pb2+ ar e soluble. A ll carbonates, except those of Group 1 and NH4+, ar e soluble. Write the compound formed from these ions: Soluble or Not CaCO3 NO NH4Cl YES PbBr2 NO AgSO4 NO CaNO3 YES MgSO4 YES Al(NO3)3 YES Na2CO3 YES K2O YES (NH4)2CO3 YES ZnSO4 CaCl CuNO3 MgCO3 CuSO4 MgNO3 K2CO3 AgCl YES YES YES NO YES YES YES NO # Cations Cation # Anions 2 NH4 1 SO4 2 Fe 3 + 3 S2- Fe2 S 3 1 Cu2 + 2 C2 H3 O2 - Cu(C2 H3 O2 )2 + Anion 2- Formula (NH4 )2 SO4 Determine the # of ions needed to make a neutral compound and then write the formula: # Cations Cation Anion Formula NH4 + PO4 3 - (NH4 )3 PO4 Ba 2 + NO3 - Ba(NO3 )2 Al CO3 2 - Al2 (CO3 )3 Sr 2+ OH- Sr(OH)2 3+ # Anions 13 Use the Solubility Rules. Circle the compounds below that would be precipitates (compounds that do not dissolve in water): Mixed Practice State the type and balance the following reactions: BaCl2 + H2SO4 BaSO4 + 2HCl C6H12 + O2 6 CO 9 3. Zn + CuSO4 2 + 6 H2O 4. Cs + Br2 ZnSO4 + Cu 5. 2FeCO3 2 CsBr • K2Cr2O7 Ag3PO4 K2Cr2O7 Ag3PO 4 Fe(NO3)3 CuOH M gCO3 BaSO4 PbCl2 CaCl2 Fe(NO3)3 CuOH MgCO 3 BaS O 4 PbCl 2 CaCl2 1. 2. FeO + CO2 Net Ionic Equations In a precipitation reaction a product of the reaction is only slightly soluble, or insoluble. This product is formed as a solid, also known as a precipitate. Solubility Rules can be used to determine if a product is insoluble (forms a precipitate) p. 284 Sect 4 Net Ionic Equations Three ways to write the same equation (usually with double replacement rxns): 1. Total Molecular Equation 2. Total Ionic Equation 3. Net Ionic Equation Ions in solution that are not used to form the precipitate: spectator ions Completing Equations Also called “Predicting Products” You have learned to recognize the different types of reactions AND How to Total them. You need to remember: Ion charges from the Periodic table (Ch 5) Writing Ionic formulas correctly (Ch 5) Acid names and formulas(Ch 5) Polyatomic ions(Ch 5) Diatomic elements (Lucky 7) Water ionizes to make H+ and OHUse Activity series for single replacement Use Solubility rules for double replacement 14 Synthesis Reactions Making ONE PRODUCT. Displacement Reactions Also called Replacement reactions Single Displacement/Replacement Activity series used as a reference Net Ionic Equations 1.Only the reactants and product taking part in the precipitation are written in the equation (the reactants as ions, the product as a molecule.) 2. Spectator Ions are not included in the equation 3.It is important to include the states of matter in the chemical equation: (s) for solid, the precipitate (g) for gas (l) for liquid (aq) for substances in aqueous solution Decomposition Reactions ONE REACTANT falls apart. GOAL Ability to to apply solubility rules to double displacement reactions. Net Ionic Equations Equations for precipitation reactions (3): Molecular Equations All reactants and products are written as if they are molecules Ionic Equations All reactants and products that are soluble are written as ions, only the precipitate is written as if it were a molecule Net Ionic Equation Written as for Ionic Equation except that spectator ions are not included in the equation: You have to write all three in net ionic 15 Net Ionic Equations AgNO3 (aq) + NaCl(aq) Net Ionic Equations AgCl(s) + NaNO3(aq) AgNO3 NaCl What happens when you put AgNO3 and NaCl in water? Net Ionic Equations Net Ionic Equations IONIC EQUATIONS IONIC EQUATIONS 3 NaClAgNO NaCl NaCl AgNO3 3 NaCl AgNO NaCl NaCl AgNO 3 AgNO3 AgNO AgNO 3 Na+ 3NaCl + Ag NO3 Cl- NaClAgNO3 NaCl AgNO3 NaCl AgNONaCl 3 Na+ +ClAg+ NO3Ag Cl Na+ Na+ NO3 + Ag NO3ClAgCl Net Ionic Equations Ionic Equations IONIC EQUATIONS AgNO3 (aq) + NaCl(aq) + NO 3NO3 Na Na+ Na+ NO3 + + Na NO3NO3 Na + NO Na+ Na + 3 NO - NO3 Na+ Na AgCl(s) + NaNO3(aq) ionic equation - 3 AgCl(s) + - + - Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq ) - AgCl (s) + NO3 (aq) + Na+ (aq) Ag + (aq) + Cl- (aq) AgCl (s) 16 Total Molecular Eqn Total Ionic Eqns This is what we have been doing. Write the Write the aqueous compounds as separate ions. Be compounds with the ions together. Example: NaCl (aq) + AgNO3 (aq) Keep the solid(insoluble) ions or water molecules AgCl (s) + NaNO3(aq) sure to put the CHARGES ON THE IONS! together. Example: Na+ (aq) + Cl- (aq) + Ag+(aq) + NO3- (aq) AgCl (s) + Na+(aq)+ NO3-(aq) Net Ionic Equations Net Equations TakeIonic the Total ionic equations and remove any ion that is aqueous on both sides. These ions are called Spectator Ions. OR Find the Solid product or water, keep that part AND keep the reactant ions that made the solid or water. Ex:Ag+ (aq) + Cl- (aq) AgCl(s) AgCl(s) Net Ionic Equations 1) Write the (balanced!) molecular equation first - Reaction products: swap cations and anions - Predict solubility (using S olubility rules) Net Ionic Equations AgNO3 (aq) + NaCl(aq) AgCl(s) + NaNO3(aq) 2) Write the Total ionic equation next - (s) compounds don’t ionize - (aq) compounds do ionize ion subscripts in the molecular equation become coefficients in the Total ionic equation! 3) Write the net ionic equation next - cancel spectator ions The net ionic equation is just a “simplified” form of the total ionic equation 17 Net Ionic Equations Net Ionic Equations T he net ionic equation is constructed from the ionic equation: Ag+ (aq) + NO 3- (aq) + Na+ (aq) + Cl- (aq) AgCl (s) + NO3 - (aq) + Na+ (aq) Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq) AgCl (s) + NO 3- (aq) + Na + (aq) Net Ionic Equations Net Ionic Equations Ag + (aq) + NO 3- (aq) + Na+ (aq) + Cl - (aq ) Ag+ (aq) + NO3 - (aq) + N a+ (aq) + Cl - (aq) AgCl (s) + NO3- (aq) + Na + (aq) AgCl (s) + NO3- (aq) + Na+ (aq) Net Ionic Equations Net Ionic Equations No3- and Na+ are not participating in the reaction + + - + - + - Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq ) - Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq) - - + AgCl (s) + NO3 (aq) + Na (aq) + AgCl (s) + NO3 (aq) + Na (aq) 18 Net Ionic Equations + - + Net Ionic Equations Ag+ and Cl - are reacting to form - Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq ) + - + AgCl (s) + NO3 (aq) + Na (aq) - + - Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq ) - + AgCl (s) + NO3 (aq) + Na (aq) net ionic equation net ionic equation + - Ag (aq) + Cl (aq) Ag+ (aq) + Cl- (aq) Net Ionic Equations Net Ionic Equations Ag+ and Cl - are reacting to form + - + - Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq) AgCl (s) + NO3 + - + - Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq ) + (aq) + Na (aq) - net ionic equation Ag+ (aq) + Cl- (aq) + AgCl (s) + NO3 (aq) + Na (aq) net ionic equation + - Ag (aq) + Cl (aq) AgCl (s) Net Ionic Equations net ionic equation Ag+ (aq) + Cl- (aq) AgCl (s) Pb(NO 3)2 + 2NaI → PbI2 + 2NaNO 3 (aq) (aq) (s) (aq) 19 Net Ionic Equations ANOTHER NET IONIC RXN Lead (II) Nitrate + Sodium Iodide Ba(NO3)2 (aq) + 2NiSO4 (aq) → BaSO4(s) +2 Ni(NO3)2(aq) Ionic Equation Barium Nitrate and Nickel (II) Sulfate Ba(NO3)2 + NiSO4 Ba2+(aq) + 2NO3-(aq) + 2Ni2+(aq) + SO42-(aq) BaSO4(s) + 2Ni+(aq) + 2NO3- (aq) Cancel the “spectator ions” that appear on both sides of the arrow Ba2+(aq) + 2NO3- (aq) + 2Ni2+(aq) + SO42+(aq) → BaSO4(s) + 2Ni2+(aq) + 2NO3- (aq) “Net Ionic” Equation: Pb2+(aq) + 2I-(aq) → PbI2(s) Net Ionic Equation Spectator Ion Spectator Ion Spectator Ion Spectator Ion Precipitate Spectator Ions Precipitate Precipitate Precipitat e Precipitate Net Ionic Equations Net Ionic Equations Silver Nitrate + Potassium Dichromate 2AgNO3 (aq) + K2Cr2O7 (aq) Ag2Cr2O7 (s) + 2KNO3(aq) 2Ag+ (aq) +2NO3-(aq) +2K+(aq) + Cr2O72- (aq) Ag2Cr2O7 (s) +2K+ (aq)+2NO3-(aq) 2 Ag+ (aq) + Cr2O72-(aq) Precipitate Ag2Cr2O7(s) Potassium and nitrate were the spectator ions Copper(II) Sulfate + Sodium Hydroxide CuSO4 (aq) + 2NaOH (aq) Cu(OH)2(s) + Na2SO42(aq) Cu2+ (aq) +SO42-(aq) + 2Na+ (aq) +2OH-(aq) Cu(OH)2(s) + 2Na+(aq) +SO42-(aq) Cu2+ (aq) + 2OH-(aq) Cu(OH)2(s) sodium and sulfate were the spectator ions 20 Net Ionic Equations Net Ionic Equations Copper(II) Sulfate + Barium Nitrate Cu(NO3)2 (aq) ) + BaSO4(s) 2- 2+ (aq) +SO 4 (aq) + Ba Cu(NO3)2(aq) + Ag2SO42(s) CuSO4 (aq) + 2AgNO3 (aq) CuSO4 (aq) + Ba(NO3)2 (aq) Cu2+ Copper(II) Sulfate + Silver Nitrate - (aq) +2NO 3 (aq) Cu2+ (aq) +SO42-(aq) + 2Ag+ (aq) +2NO3-(aq) Cu2+ (aq) +2(NO3) -(aq) + Ag2SO4(s) BaSO4(s) + Cu2+ (aq) +2NO3-(aq) Ba2+ (aq) + SO42- (aq) BaSO4 (s) copper(II) and nitrate were the spectator ions Net Ionic Equations Cu2+ (aq) + 2OH-(aq) Silver and Nitrate were the spectator ions Net Ionic Equations Silver Nitrate + Sodium Hydroxide AgNO3 (aq) + NaOH (aq) Silver Nitrate + Potassium Chloride AgOH (s) + NaNO3(aq) AgNO3 (aq) + KCl (aq) Ag+ (aq) +NO3-(aq) +Na+(aq) + OH- (aq) AgOH(s) +Na+ (aq)+NO3-(aq Ag+ (aq) + OH-(aq) AgOH(s) Sodium and nitrate were the spectator ions Net Ionic Equations Barium Nitrate + Sodium Hydroxide Ba(NO3)2 (aq) + 2NaOH (aq) 2Na(NO3) (aq) + Ba(OH)2 (s) Ba2+ (aq) +2NO3-(aq) + 2Na+ (aq) +2OH-(aq) + 2Na+ (aq) +2NO3-(aq) + Ba(OH)2 (s) Ba2+ (aq) + 2OH- (aq) Cu(H)2(s) AgCl (s) + KNO3(aq) Ag+ (aq) +NO3-(aq) +K+(aq) + Cl- (aq) AgCl (s) +K+ (aq)+NO3-(aq) Ag+ (aq) + Cl-(aq) AgCl(s) Potassium and nitrate were the spectator ions Acids and Bases( H+ and OH-) Rxn (Actually a double displacement) When acids (HA) and Bases (ZOH) mix, the H+ and OH- combine to become H2O(l). This is called a neutralization reaction. The water H2O(l) stays together like insoluble solids. So you keep it in the Net Ionic equation. Ba(OH)2 (s) Na and Nitrate were the spectator ions 21 ACID BASE REACTIONS Acid: A Hydrogen donor ACID BASE REACTIONS One example of an acid-base reaction is the reaction of hydrobromic acid (HBr) with sodium hydroxide(NaOH): Base: A Hydrogen acceptor Ha + bOH ---> ---> H2O + ba HBr + NaOH ---> NaBr + H2O (l) This is a special k ind of double displacement reaction that tak es place when an acid and base react with each other. The H+ ion in the acid reacts with the OH- ion in the base, causing the formation of water. Generally, the product of this reaction is some ionic salt and water. REACTION REVIEW 1) Does your reaction have oxygen as one of it's reactants and an carbon dioxide and water as products? If yes, then it's a combustion reaction 2) Does your reaction have two (or more) chemicals combining to form one chemical? If yes, then it's a synthesis reaction 3) Does your reaction have one large molecule falling apart to make several small ones? If yes, then it's a decomposition reaction 4) Does your reaction have any molecules that contain only one element? If yes, then it's a single displacement reaction REACTION REVIEW 5) Does your reaction have transfer of H + ion then it's an acid-base reaction. 6) If you haven't answered "yes" to any of the questions above, then you've got a double displacement reaction HCl(aq) + NaOH(aq) H2O(l) + NaCl(aq) H+(aq) + Cl-(aq)+ Na+(aq)+OH- (aq) H2O (l) Na+(aq)+Cl-(aq) H+(aq) + -OH(aq) H2O(l) What is the Net Ionic Equation for the reaction: HCl(aq) + NaOH(aq) ? 22 Net Ionic Equations ACID BASE Hydrosulfic Acid + Barium Hydroxide H2S (aq) + Ba(OH)2 (aq) BaS (aq) + 2H2O(l) 2H+ (aq) +S2-(aq) +Ba2+ (aq) + 2OH- (aq) Ba (aq) + S (aq) +2H2O (l) Barium and Sulfur were the spectator ions 23