chemical reactions
DESCRIPTION
Chemical Reactions. Chapter 9. Chemical Reactions. chemical reaction- The process by which one or more substances are rearranged to form different substances Evidence that a chemical reaction may have occurred: Change in temperature Change in color Odor Gas bubbles - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/1.jpg)
Chemical ReactionsCHAPTER 9
![Page 2: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/2.jpg)
chemical reaction- The process by which one or more substances are rearranged to form different substances
Evidence that a chemical reaction may have occurred:– Change in temperature– Change in color– Odor – Gas bubbles– Appearance of a solid
Chemical Reactions
![Page 3: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/3.jpg)
Activity
In your notebook complete the thinking map by Identifing three examples of chemical reactions you have seen, heard, or
smelled in the last 24 hours. Think about activities at home, at school, or outside.
Depict each example Include any evidence you have that a chemical reaction was occurring.
![Page 4: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/4.jpg)
Representing Chemical Reactions
Chemists use statements called equations to represent chemical reactions.
•Reactants are the starting substances.•Products are the substances formed in the reaction.
![Page 5: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/5.jpg)
Activity
Label the chemical state each symbol below identifies in a chemical equation.
(s) _________________________________________________________ (g) _________________________________________________________ (aq) _________________________________________________________ (l)
__________________________________________________
![Page 6: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/6.jpg)
Representing Chemical Reactions
Word equations aluminum(s) + bromine(l) → aluminum bromide(s) reads as “aluminum and bromine react to produce aluminum bromide”
Skeleton equations use symbols and formulas to represent the reactants and products) Al(s) + Br(l) → AlBr3(s)
Both word and skeleton equations lack information about how many atoms are involved in the reaction.
![Page 7: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/7.jpg)
Chemical equation- a statement that uses chemical formulas to show the identities and relative amounts of the substances involved in a chemical reaction.
Representing Chemical Reactions
![Page 8: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/8.jpg)
Activity
In your notebook on the next page Recreate the following table
Organize types of equations that can express a chemical reaction. In the second column, list the elements (words, coefficients, etc.) that are used to create each equation. In the third column, rank each equation from 1 to 3, giving a 3 to the equation that provides the most information,
and a 1 to the equation that provides the least information.
![Page 9: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/9.jpg)
Balancing Chemical Equations
This figure shows the balanced equation for the reaction between aluminum and bromine.
![Page 10: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/10.jpg)
Coefficient- in a chemical equation is the number written in front
of a reactant or product, - describing the lowest whole-number ratio of the
amounts of all the reactants and products
Balancing Chemical Equations
![Page 11: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/11.jpg)
Balancing Chemical Equations
The most fundamental law in chemistry is the law of conservation of mass.•Balanced equations show this law.
![Page 12: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/12.jpg)
Classify chemical reactions.
metal: an element that is a solid at room temperature, a good conductor of heat and electricity, and is generally shiny
Identify the characteristics of different classes of chemical reactions.
Classifying Chemical Reactions
![Page 13: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/13.jpg)
synthesis reaction
combustion reaction
decomposition reaction
single-replacement reaction There are four types of chemical
reactions: synthesis, combustion, decomposition, and replacement reactions.
double-replacement reaction
precipitate
Classifying Chemical Reactions
![Page 14: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/14.jpg)
Chemists classify reactions in order to organize the many types.
A synthesis reaction is a reaction in which two or more substances react to produce a single product.
Classifying Chemical Reactions
Types of Chemical Reactions
A + B → AB
![Page 15: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/15.jpg)
When two elements react, the reaction is always a synthesis reaction.
Classifying Chemical Reactions
Types of Chemical Reactions (cont.)
![Page 16: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/16.jpg)
In a combustion reaction, oxygen combines with a substance and releases energy in the form of heat and light.
Heated hydrogen reacts with oxygen to produce heat and water in a combustion reaction. This is also a synthesis reaction.
Classifying Chemical Reactions
Types of Chemical Reactions (cont.)
![Page 17: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/17.jpg)
A decomposition reaction is one in which a single compound breaks down into two or more elements or new compounds.
Decomposition reactions often require an energy source, such as heat, light, or electricity, to occur.
Classifying Chemical Reactions
Decomposition Reactions
AB → A + B
![Page 18: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/18.jpg)
A reaction in which the atoms of one element replace the atoms of another element in a compound is called a single replacement reaction.
A + BX → AX + B
Classifying Chemical Reactions
Replacement Reactions
![Page 19: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/19.jpg)
A metal will not always replace a metal in a compound dissolved in water because of differing reactivities.
An activity series can be used to predict if reactions will occur.
Classifying Chemical Reactions
Replacement Reactions (cont.)
![Page 20: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/20.jpg)
Halogens frequently replace other halogens in replacement reactions.
Halogens also have different reactivities and do not always replace each other.
Classifying Chemical Reactions
Replacement Reactions (cont.)
![Page 21: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/21.jpg)
Double replacement reactions occur when ions exchange between two compounds.
Classifying Chemical Reactions
Replacement Reactions (cont.)
This figure shows a generic double replacement equation.
![Page 22: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/22.jpg)
The solid product produced during a chemical reaction in a solution is called a precipitate.
All double replacement reactions produce either water, a precipitate, or a gas.
Classifying Chemical Reactions
Replacement Reactions (cont.)
ANIMATION
![Page 23: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/23.jpg)
This table shows the steps to write double replacement reactions.
Classifying Chemical Reactions
Replacement Reactions (cont.)
![Page 24: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/24.jpg)
This table summarizes different ways to predict the products of a chemical reaction.
Classifying Chemical Reactions
Replacement Reactions (cont.)
![Page 25: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/25.jpg)
LAB
Looking at some examples of chemical reactions
![Page 26: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/26.jpg)
QUIZ TOMORROW
![Page 27: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/27.jpg)
Which of the following is NOT one of the four types of reactions?
A. deconstructive
B. synthesis
C. single replacement
D. double replacement
Section Check
![Page 28: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/28.jpg)
The following equation is what type of reaction?
KCN(aq) + HBr(aq) → KBr(aq) + HCN(g)
A. deconstructive
B. synthesis
C. single replacement
D. double replacement
Section Check
![Page 29: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/29.jpg)
Describe aqueous solutions.
solution: a uniform mixture that might contain solids, liquids, or gases
Write complete ionic and net ionic equations for chemical reactions in aqueous solutions.
Predict whether reactions in aqueous solutions will produce a precipitate, water, or a gas.
Reactions in Aqueous Solutions
![Page 30: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/30.jpg)
aqueous solution
solute
solvent
Double-replacement reactions occur between substances in aqueous solutions and produce precipitates, water, or gases.
complete ionic equation
spectator ion
net ionic equation
Reactions in Aqueous Solutions
![Page 31: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/31.jpg)
An aqueous solution contains one or more dissolved substances (called solutes) in water.
The solvent is the most plentiful substance in a solution.
Reactions in Aqueous Solutions
Aqueous Solutions
![Page 32: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/32.jpg)
Water is always the solvent in an aqueous solution.
There are many possible solutes—sugar and alcohol are molecular compounds that exist as molecules in aqueous solutions.
Compounds that produce hydrogen ions in aqueous solutions are acids.
Reactions in Aqueous Solutions
Aqueous Solutions (cont.)
![Page 33: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/33.jpg)
Ionic compounds can also be solutes in aqueous solutions.
When ionic compounds dissolve in water, their ions separate in a process called dissociation.
Reactions in Aqueous Solutions
Aqueous Solutions (cont.)
![Page 34: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/34.jpg)
When two solutions that contain ions as solutes are combined, the ions might react.
If they react, it is always a double replacement reaction.
Three products can form: precipitates, water, or gases.
Reactions in Aqueous Solutions
Types of Reactions in Aqueous Solutions
![Page 35: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/35.jpg)
Aqueous solutions of sodium hydroxide and copper(II) chloride react to form the precipitate copper(II) hydroxide.
2NaOH(aq) + CuCl2(aq) → 2NaCl(aq) + Cu(OH)2(s)
Ionic equations that show all of the particles in a solution as they actually exist are called complete ionic equations.
2Na+(aq) + 2OH–(aq) + Cu2+ (aq)+ 2Cl–(aq) → 2Na+(aq) + 2Cl–(aq) + Cu(OH)2(s)
Reactions in Aqueous Solutions
Types of Reactions in Aqueous Solutions (cont.)
![Page 36: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/36.jpg)
Ions that do not participate in a reaction are called spectator ions and are not usually written in ionic equations.
Formulas that include only the particles that participate in reactions are called net ionic equations.
2OH–(aq) + Cu2+(aq) → Cu(OH)2(s)
Reactions in Aqueous Solutions
Types of Reactions in Aqueous Solutions (cont.)
![Page 37: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/37.jpg)
Some reactions produce more water molecules.
No evidence of a chemical reaction is observable.
HBr(aq) + NaOH(aq) → H2O(l) + NaBr(aq)
Without spectator ions H+(aq) + OH–(aq) → H2O(l).
Reactions in Aqueous Solutions
Types of Reactions in Aqueous Solutions (cont.)
![Page 38: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/38.jpg)
Gases that are commonly produced are carbon dioxide, hydrogen cyanide, and hydrogen sulfide.
2HI(aq) + Li2S(aq) → H2S(g) + 2LiI(aq)
Reactions in Aqueous Solutions
Types of Reactions in Aqueous Solutions (cont.)
![Page 39: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/39.jpg)
Another example is mixing vinegar and baking soda, which produces carbon dioxide gas.
HCl(aq) + NaHCO3(aq) → H2CO3(aq) + NaCl(aq)
H2CO3(aq) decomposes immediately.
H2CO3(aq) → H2O(l) + CO2(g)
Reactions in Aqueous Solutions
Types of Reactions in Aqueous Solutions (cont.)
![Page 40: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/40.jpg)
Two reactions can be combined and represented by a single chemical reaction.
SECTION
9.3Reactions in Aqueous
SolutionsTypes of Reactions in Aqueous Solutions (cont.)
![Page 41: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/41.jpg)
Reaction 1 HCl(aq) + NaHCO3(aq) → H2CO3(aq) + NaCl(aq)
Reaction 2 H2CO3(aq) → H2O(l) + CO2(g)
Combined equationHCl(aq) + NaHCO3(aq) + H2CO3(aq) → H2CO3(aq) + NaCl(aq) + H2O(l) + CO2(g)Overall equationHCl(aq) + NaHCO3(aq) → H2O(l) + CO2(g) + NaCl(aq)
Reactions in Aqueous Solutions
Types of Reactions in Aqueous Solutions (cont.)
![Page 42: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/42.jpg)
What is the solvent in an aqueous solution?
A. hydrogen
B. sodium ions
C. water
D. alcohol
Section Check
![Page 43: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/43.jpg)
An equation that includes only the particles that participate in a reaction is called:
A. net ionic equation
B. spectator ions
C. complete ionic equation
D. reduced ionic equation
Section Check
![Page 44: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/44.jpg)
Key ConceptsSome physical changes are evidence that indicate a chemical reaction has
occurred.
Word equations and skeleton equations provide important information about a chemical reaction.
A chemical equation gives the identities and relative amounts of the reactants and products that are involved in a chemical reaction.
Balancing an equation involves adjusting the coefficients until the number of atoms of each element is equal on both sides of the equation.
Study Guide
SECTION
9.1Reactions and
Equations
![Page 45: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/45.jpg)
Classifying chemical reactions makes them easier to understand, remember, and recognize.
Activity series of metals and halogens can be used to predict if single-replacement reactions will occur.
Study Guide
SECTION
9.2Classifying Chemical
Reactions
Key Concepts
![Page 46: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/46.jpg)
In aqueous solutions, the solvent is always water. There are many possible solutes.
Many molecular compounds form ions when they dissolve in water. When some ionic compounds dissolve in water, their ions separate.
When two aqueous solutions that contain ions as solutes are combined, the ions might react with one another. The solvent molecules do not usually react.
Reactions that occur in aqueous solutions are double-replacement reactions.
Study Guide
SECTION
9.3Reactions in Aqueous
Solutions
Key Concepts
![Page 47: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/47.jpg)
The law of conservation of mass requires what in a chemical reaction equation?
A. both sides of the equation to contain the same substances
B. the reactants to have the same amount of molecules as the products
C. both sides to have the same amount of atoms of each element
D. the products to have fewer molecules than the reactants
CHAPTER
9 Chemical ReactionsChapter
Assessment
![Page 48: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/48.jpg)
A reaction that gives off heat is what type of reaction?
A. single replacement reaction
B. double replacement reaction
C. synthesis reaction
D. combustion reaction
CHAPTER
9 Chemical ReactionsChapter
Assessment
![Page 49: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/49.jpg)
Ions that are present in a solution and do not participate in a chemical reaction when another substance is added are called ____.
A. spectator ions
B. reactants
C. products
D. net ions
CHAPTER
9 Chemical ReactionsChapter
Assessment
![Page 50: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/50.jpg)
A double replacement reaction produces all of the following except ____.
A. gases
B. solids
C. light
D. water
CHAPTER
9 Chemical ReactionsChapter
Assessment
![Page 51: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/51.jpg)
What type of reaction is the following?
2H2O(l) + energy → H2(g) + O2(g)
A. synthesis reaction
B. decomposition reaction
C. combustion reaction
D. replacement reaction
CHAPTER
9 Chemical ReactionsChapter
Assessment
![Page 52: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/52.jpg)
What type of reaction is the following?
2H2(g) + O2(g) → 2H2O(l)
A. replacement reaction
B. synthesis
C. decomposition reaction
D. double replacement reaction
CHAPTER
9 Chemical ReactionsStandardized Test Practice
![Page 53: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/53.jpg)
A precipitate forms in a double replacement reaction only if:
A. the reactivities of the compounds differ
B. the new compound is denser than water
C. the new compound is soluble in water
D. the new compound is not soluble in water
CHAPTER
9 Chemical ReactionsStandardized Test Practice
![Page 54: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/54.jpg)
A ____ is a statement that uses chemical formulas to show the identities and relative amounts of the substances involved in a chemical reaction.
A. word equation
B. skeleton equation
C. chemical equation
D. balanced equation
CHAPTER
9 Chemical ReactionsStandardized Test Practice
![Page 55: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/55.jpg)
Predict the type of reaction.
LiBr2 (aq) + 2NaOH (aq) → ____
A. synthesis reaction
B. combustion reaction
C. single replacement reaction
D. double replacement reaction
CHAPTER
9 Chemical ReactionsStandardized Test Practice
![Page 56: Chemical Reactions](https://reader035.vdocument.in/reader035/viewer/2022062410/568163ca550346895dd50679/html5/thumbnails/56.jpg)
Which reactions are essentially the opposite of synthesis reactions?
A. single-replacement
B. decomposition
C. combustion
D. double-replacement
CHAPTER
9 Chemical ReactionsStandardized Test Practice