Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The...
-
Upload
maura-soper -
Category
Documents
-
view
213 -
download
0
Transcript of Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The...
![Page 1: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/1.jpg)
www.cengage.com/chemistry/cracolice
Mark S. CracoliceEdward I. Peters
Mark S. Cracolice • The University of Montana
Chapter 8Chemical Reactions
![Page 2: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/2.jpg)
Evidence of Chemical Change
Evidence of Chemical Change
1. Color change
2. Formation of a solid
3. Formation of a gas
4. Absorption or release of heat energy
5. Emission of light energy
![Page 3: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/3.jpg)
Evidence of Chemical Change
Color change
![Page 4: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/4.jpg)
Evidence of Chemical Change
Formation of a solid
![Page 5: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/5.jpg)
Evidence of Chemical Change
Formation of a gas
![Page 6: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/6.jpg)
Evidence of Chemical Change
Evolution of heat and light
![Page 7: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/7.jpg)
Evidence of Chemical Change
Emission of light
![Page 8: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/8.jpg)
Evidence of Chemical Change
Heat transfer as evidence
of physical change
Many physical changes are accompanied by heat transfer, so be cautious in using this form of evidence of a chemical change.
![Page 9: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/9.jpg)
Evolution of a Chemical Equation
When solid potassium is added to liquid water, a reaction occurs, producing hydrogen gas, potassium hydroxide
solution, and heat:
![Page 10: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/10.jpg)
Evolution of a Chemical Equation
Chemists have developed a standardized shorthand
method for describing chemical reactions, such
as the reaction of sodium and water, in writing.
State Symbols and Their Meanings
Symbol Meaning
(s) solid
(l) liquid
(g) gas
(aq) aqueous (dissolved in water)
![Page 11: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/11.jpg)
Evolution of a Chemical Equation
Solid potassium K(s)
plus +
liquid water H2O(l)
yields
hydrogen gas H2(g)
plus +
potassium hydroxide solution KOH(aq)
![Page 12: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/12.jpg)
Evolution of a Chemical Equation
The equation
K(s) + H2O(l) H2(g) + KOH(aq)is said to be unbalanced because the number of atoms of each
element is not the same before and after the chemical change.
An equation is balanced when the number of atoms of each element is the same before and after the chemical change
2 K(s) + 2 H2O(l) H2(g) + 2 KOH(aq)
![Page 13: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/13.jpg)
Interpreting Chemical Equations
The particulate-level interpretation of a chemical equation:
2 H2(g) + O2(g) 2 H2O(g)
Two molecules of hydrogen react with one oxygen molecule
to form two water molecules.
![Page 14: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/14.jpg)
Interpreting Chemical Equations
The particulate-level interpretation of a chemical equation:
![Page 15: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/15.jpg)
Interpreting Chemical Equations
The molar-level interpretation of a chemical equation:
2 H2(g) + O2(g) 2 H2O(g)
Two moles of hydrogen react with one mole of oxygen
to form two moles of water.
![Page 16: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/16.jpg)
Writing Chemical Equations
1. Write the formulas of the given reactants to the left of an arrow and the formulas of the products to the right.
2. Balance the equation by adding coefficients, but do not change the qualitative description of the reaction by adding, removing, or altering any chemical formula.
![Page 17: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/17.jpg)
Combination Reactions
Combination ReactionTwo or more substances combine to form a single product:
![Page 18: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/18.jpg)
Combination Reactions
Example:
Potassium combines with oxygen to form potassium oxide.
Solution:
Write the qualitative description:
K + O2 K2O
Balance the O:
K + O2 2 K2O
Balance the K:
4 K + O2 2 K2O
![Page 19: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/19.jpg)
Combination Reactions
Reactants: Any combination of elements and/or
compounds
Reaction type: Combination
Equation type: A + X AX
Products: One compound
![Page 20: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/20.jpg)
Decomposition Reactions
Decomposition ReactionA compound breaks down into simpler substances:
![Page 21: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/21.jpg)
Decomposition Reactions
Example:
Water is decomposed into its elements.
Solution:
Write the qualitative description:
H2O (l) H2 (g) + O2 (g)
Balance the O:
2 H2O (l) 2 H2 (g) + O2 (g)
![Page 22: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/22.jpg)
Decomposition Reactions
Example:
Calcium carbonate (limestone) is decomposed into carbon dioxide and calcium oxide (lime).
CaCO3(s) CaO (s) + CO2 (g)
![Page 23: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/23.jpg)
Decomposition Reactions
Reactants: One compound
Reaction type: Decomposition
Equation type: AX A + X
Products: Any combination of elements and
compounds
![Page 24: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/24.jpg)
Single-Replacement Reactions
Single-Replacement ReactionOne element appears to replace another in a compound:
![Page 25: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/25.jpg)
Single-Replacement Reactions
Example:
Potassium is able to replace hydrogen in water.
2 K(s) + 2 HOH (l) H2 (g) + 2 KOH (aq)
![Page 26: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/26.jpg)
Single-Replacement Reactions
Example:
A copper strip is placed in a solution of silver nitrate.
Solution:
Copper displaces silver from silver nitrate
Cu (s) + 2AgNO3 (aq) Cu(NO3)2 (aq) + 2 Ag (s)
The reverse reaction does not occur
![Page 27: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/27.jpg)
Single-Replacement Reactions
Example:
A magnesium strip is placed in a solution of hydrochloric acid.
Mg (s) + 2HCl (aq) MgCl2 (aq) + H2 (g)
Magnesium displaces hydrogen from acid
![Page 28: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/28.jpg)
Single-Replacement Reactions
Summary:
Single-Replacement Reactions
Reactants: Element (A) plus a solution of an acid
or an ionic compound (BX)
Reaction type: Single-replacement
Equation type: A + BX AX + B
Products: Element (B) must be less active than element A
![Page 29: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/29.jpg)
Double-Replacement Reactions
Double-Replacement ReactionIons of two reactants appear to change partners:
![Page 30: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/30.jpg)
Double-Replacement Reactions
Double-Replacement Reaction between two ionic compounds.
When solutions of two ionic compounds are mixed, positive ions from one compound may combine with negative ions from the other compound to form a solid (precipitate) or a molecular compound (water, weak acid, weak base, gas)
![Page 31: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/31.jpg)
Formation of a precipitate
Formation of silver chloride precipitate from sodium chloride and silver nitrate.
NaCl (aq) + AgNO3 (aq) NaNO3 (aq) + AgCl (s)
Formation of barium sulfate precipitate from barium chloride and sodium sulfate.
BaCl2 (aq) + Na2SO4 (aq) BaSO4 (s) + 2 NaCl (aq)
![Page 32: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/32.jpg)
Neutralization Reactions: Formation of water
Neutralization reaction is a reaction between an acid and a base. One hydrogen ion from acid reacts with one hydroxide ion from a base to form one water molecule.
Neutralization of hydrochloric acid by sodium hydroxide.
HCl (aq) + NaOH (aq) NaCl (aq) + H2O (l)
Reaction between sulfuric acid and solid aluminum hydroxide.
3 H2SO4 (aq) + 2 Al(OH)3 (s) Al 2(SO4)3 (aq) + 3 H2O (l)
![Page 33: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/33.jpg)
Formation of weak acid
Reaction of hydrochloric acid and sodium acetate to form acetic acid (weak acid)
HCl (aq) + NaCH3CO2 (aq) NaCl (aq) + HCH3CO2 (aq)
Reaction between hydrochloric acid and sodium sulfide to form hydrosulfuric acid (weak acid)
Na2S(aq) + 2 HCl (aq) 2 NaCl (aq) + H2S (aq)
![Page 34: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/34.jpg)
Formation of a gas
Reaction between hydrochloric acid and sodium carbonate to form carbon dioxide gas
Na2CO3 (aq) + 2 HCl (aq) 2 NaCl (aq) + H2O(l) + CO2 (g)
![Page 35: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/35.jpg)
Double-Replacement Reactions
Summary:Double-Replacement Reactions
Reactants: Solutions of two ionic compounds,(AX + BY)
Reaction type: Double-replacement
Equation type: AX + BY AY + BX
Products: Two new compounds (AY + BX), one of which may be a solid, water, weak acid, weak base, or a gas
![Page 36: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/36.jpg)
Summary
![Page 37: Www.cengage.com/chemistry/cracolice Mark S. Cracolice Edward I. Peters Mark S. Cracolice The University of Montana Chapter 8 Chemical Reactions.](https://reader035.fdocuments.us/reader035/viewer/2022070306/5519c9c6550346695e8b4a35/html5/thumbnails/37.jpg)
Homework
Homework: 9, 15, 19, 23, 27, 29, 31, 35, 39, 53, 59, 69, 76