chapter 4 reactions in aqueous solutions. types of chemical reactions chemical reactions discussed...
TRANSCRIPT
![Page 1: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/1.jpg)
Chapter 4
Reactions in Aqueous Solutions
![Page 2: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/2.jpg)
Types of Chemical Reactions
• Chemical Reactions discussed in College Chemistry can be broken down into 3 main categories– Precipitation reactions– Acid-Base reactions– Oxidation-Reduction (redox) reactions
![Page 3: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/3.jpg)
Types of Chemical Reactions
• Precipitation Reactions: A process in which an insoluble solid (precipitate) drops out of the solution.– Clear solutions of two ionic compounds when
mixed form a cloudy solution (cloudiness indicates solid)
![Page 4: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/4.jpg)
Types of Reactions
• Acid–Base Neutralization: A process in which an acid reacts with a base to yield water plus an ionic compound called a salt.– The driving force of this reaction is the
formation of the stable water molecule.
![Page 5: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/5.jpg)
Types of Reaction
• Metathesis Reactions (Double
Displacement Reaction): These are
reactions where two reactants just
exchange parts.
AX + BY AY + BX
![Page 6: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/6.jpg)
Types of Reactions
• Oxidation–Reduction (Redox) Reaction: A process in which one or more electrons are transferred between reaction partners.– The driving force of this reaction is the
decrease in electrical potential.
![Page 7: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/7.jpg)
Precipitation Reactions
• Develop the reaction equation
• Balance the reaction equation
• Predict the state of matter of each species present
![Page 8: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/8.jpg)
Precipitation Reactions and Solubility Rules
• To predict whether a precipitation reaction will occur must be able to predict whether a compound is soluble or not– Solubility rules
![Page 9: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/9.jpg)
Solubility Rules
• Salts - soluble:• All alkali metal and ammonium ion salts
• All salts of the NO3–, ClO3
–, ClO4–, C2H3O2
–,
and HCO3– ions
![Page 10: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/10.jpg)
Solubility Rules
• Salts which are soluble with exceptions:• Cl–, Br–, I– ion salts except with Ag+, Pb2+, &
Hg22+
• SO42– ion salts except with Ag+, Pb2+, Hg2
2+,
Ca2+, Sr2+, & Ba2+
![Page 11: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/11.jpg)
Solubility Rules
• Salts which are insoluble with exceptions:
• O2– & OH– ion salts except with the alkali metal ions,
and Ca2+, Sr2+, & Ba2+ ions
• CO32–, PO4
3–, S2–, CrO42–, & SO3
2– ion salts except with
the alkali metal ions and the ammonium ion
![Page 12: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/12.jpg)
Precipitation Reactions and Solubility Rules
• Predict the solubility of:
– (a) CdCO3 (b) MgO (c) Na2S
(d) PbSO4 (e) (NH4)3PO4 (f) HgCl2
![Page 13: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/13.jpg)
Precipitation Reaction
• Precipitation reactions only occur if a solid is produced as a product.
• If all products are aqueous compounds then no reaction has taken place.
![Page 14: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/14.jpg)
Electrolytes in Aqueous Solution
• To discuss aqueous reactions, must understand how different compounds interact with water
• Electrolyte – substance that when added to water dissociates to form ions allowing for conductivity– Strong electrolytes – completely dissociate– Weak electrolytes – partially dissociate– Non-electrolyte – no dissociation in water
![Page 15: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/15.jpg)
Aqueous Reactions and Net Ionic Equations
• Molecular equations – substances involved in chemical reaction have been written using full formulas
• Complete ionic equation – shows every species as it truly appears in the reaction vessel (aqueous strong electrolytes are shown as ions)
• Net ionic equation – shows what is truly taking place in the reaction (all spectators are removed)– Must have a net ionic reaction for the reaction to occur as written
![Page 16: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/16.jpg)
Complete Ionic Equation
• AgNO3(aq) + KI(aq) → KNO3(aq) + AgI(s)
![Page 17: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/17.jpg)
Net Ionic Equation
• Shows species that undergo a change during the reaction– Obtained by removal of spectator ions.
![Page 18: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/18.jpg)
Additional Examples
• Reaction of magnesium acetate and sodium hydroxide in solution.
• Reaction of lead nitrate with potassium dichromate in solution.
![Page 19: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/19.jpg)
Acids, Bases and Neutralization Reactions
• Acid / Base Definitions– Arrhenius
• Acid – donates a H+ (H3O+)
• Base – donates an OH-
– Bronsted-Lowry • Acid – donates a H+
• Base – H+ acceptor
![Page 20: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/20.jpg)
Acids, Bases and Neutralization Reactions
Strong Acids (all)
Hydrochloric acid – HCl (aq)
Hydrobromic acid – HBr (aq)
Hydroiodic acid – HI (aq)
Sulfuric acid – H2SO4 (aq)
Nitric acid – HNO3 (aq)
Perchloric acid – HClO4 (aq)
Weak Acids (examples)
Acetic acid – HC2H3O2 (aq)
Cyanic acid – HCN (aq)
Phosphoric acid – H3PO4 (aq)
Organic acids – contain ending group
–COOH
Strong Bases (all)
Lithium hydroxide – LiOH (aq)
Sodium hydroxide – NaOH (aq)
Potassium hydroxide – KOH (aq)
Calcium hydroxide – Ca(OH)2 (aq)
Strontium hydroxide – Sr(OH)2 (aq)
Barium hydroxide – Ba(OH)2 (aq)
Weak Bases (examples)
Ammonia (ammonium hydroxide) – NH3 (aq) actually NH4OH (aq)
Organic amines – contain ending group
-NHx
![Page 21: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/21.jpg)
Electrolytes in Aqueous Solution
• To discuss aqueous reactions, must understand how different compounds interact with water
• Electrolyte – substance that when added to water dissociates to form ions allowing for conductivity– Strong electrolytes – completely dissociate– Weak electrolytes – partially dissociate– Non-electrolyte – no dissociation in water
![Page 22: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/22.jpg)
Acids, Bases and Neutralization Reactions
• Neutralization Reactions– Complete ionic reactions
• Strong electrolytes (strong acids and bases) will dissociate entirely
• Weak electrolytes are not shown as dissociated
– Net ionic for strong acids reacting with strong bases will always be for the formation of water
![Page 23: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/23.jpg)
Acids, Bases and Neutralization Reactions
• Neutralization Reaction: produces salt & water.
– HA(aq) + MOH(aq) H2O(l) + MA(aq)
• Write ionic and net ionic equations for the following:
– (a) HBr(aq) + Ba(OH)2(aq)
– (b) HCl(aq) + NH3(aq)
![Page 24: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/24.jpg)
Neutralization Reactions
• 2HBr (aq) + Ba(OH)2 (aq) → BaBr2(aq) + 2 H2O (l)
![Page 25: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/25.jpg)
Neutralization Reactions
• HCN (aq) + NaOH (aq) → NaCN (aq) + H2O (l)
![Page 26: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/26.jpg)
Problem
• Select the correct set of products for the following reaction.
Ba(OH)2(aq) + HNO3(aq) →
– A. BaN2(s) + H2O(l)
– B. Ba(NO3)2(aq) + H2O(l)
– C. Ba(s) + H2(g) + NO2(g)
– D. Ba2O(s) + NO2(g) + H2O(l)
– E. No reaction occurs
![Page 27: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/27.jpg)
Problem
• Select the net ionic equation for the reaction between lithium hydroxide and hydrobromic acid.
LiOH(aq) + HBr(aq) → H2O(l) + LiBr(aq)
– a. LiOH(aq) → Li+(aq) + OH-(aq)– b. HBr(aq) → H+(aq) + Br-(aq)
– c. H+(aq) + OH-(aq) → H2O(l)
– d. Li+(aq) + Br-(aq) → LiBr(aq)
– e. Li+(aq) + OH-(aq)+ H+(aq) + Br-(aq) → H2O(l) + LiBr(aq)
![Page 28: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/28.jpg)
Oxidation-Reduction Reactions
• Redox reactions are those involving the oxidation and reduction of species (element or ion of an element).
• Oxidation and reduction must occur together. They cannot exist alone.
• Two important types– Single displacement reactions (activity series)– Combustions – reaction of a substance with O2
![Page 29: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/29.jpg)
Oxidation Reduction Reactions
OxidationIsLoss (of electrons)
Anode Oxidation
Reducing Agent
![Page 30: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/30.jpg)
Oxidation Reduction Reactions
Reduction
Is
Gain (of electrons)
Cathode Reduction
Oxidizing Agent
![Page 31: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/31.jpg)
Redox Reactions
• Assigning Oxidation Numbers: All atoms have an
“oxidation number” regardless of whether it carries an
ionic charge.
1. An atom in its elemental state has an oxidation number
of zero.
2. An atom in a monatomic ion has an oxidation number
identical to its charge.
![Page 32: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/32.jpg)
Redox Reactions
3. An atom in a polyatomic ion or in a molecular compound usually has the same oxidation number it would have if it were a monatomic ion.
– A. Hydrogen can be either +1 or –1.
– B. Oxygen usually has an oxidation number of –2.• In peroxides, oxygen is –1.
– C. Halogens usually have an oxidation number of –1.• When bonded to oxygen, chlorine, bromine, and iodine have
positive oxidation numbers.
![Page 33: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/33.jpg)
Redox Reactions
4. The sum of the oxidation numbers must be zero for a
neutral compound and must be equal to the net charge
for a polyatomic ion.
– A. H2SO4 2(+1) + (?) + 4(–2) = 0 net charge
? = 0 – 2(+1) – 4(–2) = +6
– B. ClO4– (?) + 4(–2) = –1 net charge
? = –1 – 4(–2) = +7
![Page 34: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/34.jpg)
Problem
• Sodium tripolyphosphate is used in detergents to make them effective in hard water. Calculate the oxidation number of phosphorus in Na5P3O10.
– A. +3– B. +5– C. +10– D. +15– E. none of these is the correct oxidation number
![Page 35: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/35.jpg)
Problem
• The oxidation numbers of P, S and Cl in H2PO2
-, H2S and KClO4 are, respectively
– A. -1, -1, +3– B. +1, -2, +7– C. +1, +2, +7– D. -1, -2, +7– E. -1, -2, +3
![Page 36: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/36.jpg)
Redox Reactions
5. Whenever one atom loses electrons (is
oxidized), another atom must gain those
electrons (be reduced).
– A substance which loses electrons (oxidized) is called a
reducing agent. Its oxidation number increases.
– A substance which gains electrons (reduced) is called the
oxidizing agent. Its oxidation number decreases.
![Page 37: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/37.jpg)
Redox Reactions
• For each of the following, identify which species is the reducing agent and which is the oxidizing agent.
• Ca(s) + 2 H+(aq) Ca2+(aq) + H2(g)
• 2 Fe2+(aq) + Cl2(aq) 2 Fe3+(aq) + 2 Cl–(aq)
• SnO2(s) + 2 C(s) Sn(s) + 2 CO(g)
• Sn2+(aq) + 2 Fe3+(aq) Sn4+(aq) + 2 Fe2+(aq)
![Page 38: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/38.jpg)
Problem
• Identify the oxidizing agent in the following redox reaction.
Hg2+(aq) + Cu(s) → Cu2+(aq) + Hg(l)
– A. Hg2+(aq)– B. Cu(s)– C. Cu2+(aq)– D. Hg(l)– E. Hg2+(aq) and Cu2+(aq)
![Page 39: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/39.jpg)
Problem
• Sodium thiosulfate, Na2S2O3, is used as a "fixer" in black and white photography. Identify the reducing agent in the reaction of thiosulfate with iodine.
2S2O32-(aq) + I2(aq) → S4O6
2-(aq) + 2I-(aq)
– a. I2(aq)– b. I-(aq)– c. S2O3
2-(aq)– d. S4O6
2-(aq)– e. S2O3
2-(aq) and I-(aq)
![Page 40: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/40.jpg)
The Activity Series of the Elements
![Page 41: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/41.jpg)
The Activity Series of the Elements
• Activity series looks at the relative reactivity of a free metal with an aqueous cation.
– Fe(s) + Cu2+(aq) Fe2+(aq) + Cu(s)
– Zn(s) + Cu2+(aq) Zn2+(aq) + Cu(s)
– Cu(s) + 2 Ag+(aq) 2 Ag(s) + Cu2+(aq)
– Mg(s) + 2 H+(aq) Mg2+(aq) + H2(g)
![Page 42: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/42.jpg)
The Activity Series of the Elements
Given the following three
reactions, determine the
activity series for Cu, Zn, &
Fe.
Fe(s) + Cu2+(aq) Fe2+(aq) + Cu(s)
Zn(s) + Cu2+(aq) Zn2+(aq) + Cu(s)
Fe(s) + Zn2+(aq) NR
![Page 43: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/43.jpg)
Optional Homework
• Text – 4.24, 4.30, 4.32, 4.34, 4.36, 4.40, 4.42, 4.46, 4.48, 4.52, 4.54, 4.58, 4.60, 4.62, 4.64, 4.66, 4.68, 4.92, 4.100, 4.102, 4.108
• Chapter 4 Homework
![Page 44: Chapter 4 Reactions in Aqueous Solutions. Types of Chemical Reactions Chemical Reactions discussed in College Chemistry can be broken down into 3 main](https://reader035.vdocument.in/reader035/viewer/2022062308/56649cd75503460f9499f24a/html5/thumbnails/44.jpg)
Required Homework
• Assignment 4