Unit 6: Chemical Reactions
Unit 6:Chemical Reactions(Chapter 11)1
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Reactions: The Chemistry of ChangePart 1: Pre-QuizDIRECTIONS: Before watching the video, circle the word that correctly completes the sentence.How much do you already know about chemical reactions?1. Chemical reactions that give off heat are called (exothermic/endothermic) reactions.2. (Cellular Respiration/Photosynthesis) occurs in plants and is responsible for all life on earth.3. The substances that react in a chemical reaction are called (reactants/products).4. The substances produced in a chemical reaction are called (reactants/products).5. The symbol,, in a chemical reaction is read as (“yields”/ “makes”).6. In chemical equations, the (subscripts/coefficients) indicate the relative proportions of reactantsand products.7. A (oxidizing agent/catalyst) is a substance that speeds up a chemical reaction without beingpermanently altered.8. During chemical reactions, matter (is/is not) created or destroyed.9. To balance a chemical equation, (subsctipts/coefficients) are added to the equation.10. (Decomposition/composition) occurs when a compound breaks down into two or more simplersubstances.Part 2: Video QuestionsDIRECTIONS: While watching the video, fill in the blanks with the correct word(s).1. True or False. The combustion of fuel is an example of a chemical reaction.2. A complex series of chemical reactions called occurs in plantsand is responsible for all life on earth.3. Cellular occurs in animals and converts the light energyof the chemical energy stored in plants and other animals into the energy necessary to fuel growth,locomotion, reproduction, and other critical function.4. Chemical reactions called reactions give off heat.5. Other reactions called reactions absorb heat and cool theimmediate environment.6. True or False. During all chemical reactions, a chemical change takes place that produces newsubstances with properties different than those of the original substances.7. The original substances in a chemical reaction are called .3
8. The new substances produced by a chemical reaction are called .9. What 1700’s French chemist realized that the mass of the reactants is equal to the mass of theproducts?10. While the mass of the reactants and products is always equal, the levels are not.11. In a chemical equation, the arrow that is found between the reactants and products is read as“ ”12. The small numbers found to the lower right of the element symbols are called .13. indicate the relative proportions of reactants and products.14. True or False. Subscripts are always changed to balance a chemical equation.15. Chemical reactions can largely be broken down into three major types of reactions:16. occurs when two or more compounds or elements are combined together toform a new compound.17. List two products that synthetic polymers are used in:and18. occurs when a compound breaks down and releases two or moreelements or compounds.19. A is a substance that speeds up a chemical reaction without beingpermanently altered.20. In a replacement reaction, two compounds that separate into positiveand negative ions in a solution switch partners and form two new compounds.21. List two factors that affect the speed and strength of a chemical reaction.and22. It is possible to speed up a reaction by increasing the of one or bothreactants.23. True or False. Many chemical reactions occur in nature.4
The Chemistry of ChangeAcross:Down:1.Natural Gas, CH42.Type of reaction that absorbs heat and cools offthe immediate surroundings.7.Type of respiration process that is made up of anumber of reactions rather than a single reaction.3.Form of energy produced by a combustionreaction.Type of reaction in which one substance breaksdown into two or more simpler substances.4.Biological catalysts that speeds up reactions in thebody.5.The heart of chemistry.11. While the mass of reactants and products is alwaysequal, the levels are not.6.Small numbers that indicate the number of atomspresent in a compound.12. Combustion of fuels in automobiles and jet enginesare examples of chemical .8.Large molecules made by covalently bondingtogether simpler molecules; many plastics arecomposed of these.9.10. Dissolved in water.15. NH316. Substance that speeds up a reaction but is notconsumed in the reaction.17. Product formed from the reaction between ametallic oxide and water; a metallic hydroxide.18. Substance found on the left side of an equation.20. A horizontal arrow in a chemical equation can beread as .22. Anything that occupies space and has mass; incannot be created or destroyed.10. Product formed from the reaction between anonmetallic oxide and water.13. Numbers used to balance chemical equations.14. Another word for a composition reaction in whicha new substance is synthesized by a combinationof two or more reactants.19. Product formed in both complete and incompletecombustion reactions.21. Type of product represented by a down arrow onthe right side of an equation.23. Substances formed in a chemical reaction.24. Type of chemical reaction that gives off heat.25. Charged particles.29. Type of product represented by an up arrow onthe right side of the equation.26. Type of replacement reaction in which two solubleionic compounds “switch partners” to form aprecipitate or molecular compound.27. Solid formed in a double replacement reaction.28. Type of replacement reaction in which an elementreplaces a less reactive element in an ioniccompound.5
NamePeriodThe Chemistry of Change6
Balancing Chemical ReactionsConsider this reaction:2H2 O2 2H2OReactant: A starting substance in a chemical reaction.List the reactant(s):Product: A substance resulting from a chemical reaction.List the product(s):Consider this reaction:H2 Cl2 HClReactant SideProduct SideHow many H atoms?How many H atoms?How many Cl atoms?How many Cl atoms?Total atomsTotal atoms Does it follow the conservation of mass? Are the total atoms of each elementequal on both sides of the equation?We will use coefficients to balance this equation. Note that coefficients are not thesame as subscripts. When balancing reactions, we CANNOT change subscripts.H2 Cl2 HCl How many atoms of each element are present in the compound, Fe2(SO4)3?FeSO How many atoms of each element are present in the compound, 3Fe2(SO4)3?FeSO7
Do you remember the 7 diatomic molecules? You can only write these elements asdiatomic molecules when they are by themselves: Example: if they are in the compound HCl, you cannot write H2Cl2!!!!Balancing Chemical Equations is trial and error, but there are a few guidelines to follow:1. First, balance the atoms of elements and those that appear only once on eachside of the equation by using coefficients. NEVER change the subscript of aformula!2. Balance H atoms and O atoms after atoms of all other elements have beenbalanced.DIRECTIONS: Balance the following chemical reactions:a.)Zn HCl ZnCl2 H2b.)CH4 O2 CO2 H2Oc.) KC2H3O2 Na2S K2S NaC2H3O28
DIRECTIONS: Write a balanced chemical equation for the following reactions.d.) Bromine combines with nitrogen to produce nitrogen tribromide.e.) Solid sodium reacts with powdered sulfur to produce sodium sulfide.f.) Aqueous solutions of sulfuric acid and sodium hydroxide react to form aqueoussodium sulfate and water.g.) Benzene (C6H6) burns in air to produce carbon dioxide and water.9
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Balancing Chemical EquationsDIRECTIONS: balance the equations below by writing the correct coefficient on the space provided, even if it is a“1”. For problems 1 – 9, write the word equation on the space provided.1. N2 H2 ----- NH32. KClO3 ----- KCl O23. NaCl F2 ----- NaF Cl24. H2 O2 ----- H2O5. AgNO3 MgCl2 ----- AgCl Mg(NO3)26. AlBr3 K2SO4 ----- KBr Al2(SO4)37. FeCl3 NaOH ----- Fe(OH)3 NaCl8. P O2 ----- P2O59. HCl CaCO3 ----- CaCl2 H2O CO211
10. CH4 O2 ----- CO2 H2O11. Na H2O ----- NaOH H212. Ag2O ----- Ag O213. S8 O2 ----- SO314. CO2 H2O ----- C6H12O6 O215. K MgBr2 ----- KBr Mg16. C3H8 O2 ----- CO2 H2O17. Al N2 ----- AlN18. NaCl H2SO4 ----- Na2SO4 HCl19. Al CuSO4 ----- Al2(SO4)3 Cu20. C8H18 O2 ----- CO2 H2O21. Fe(OH)3 ----- Fe2O3 H2O22. C O2 ----- CO23. H2 S ----- H2S24. Al O2 ----- Al2O325. H2 O2 ----- H2O12
Name PeriodClassic chemBalancer/default.htmDIRECTIONS: 1) Balance each equation. If the coefficient is a “1”, write a “1” in the space provided.2) Name the substances printed in BOLD3) Write a fact about each reaction.1. Fe S -- FeSNames:Fact:2. H2 Cl2 -- HClNames:Fact:3. Mg O2 -- MgONames:Fact:4. O2 H2 -- H2OFact:5. HgO -- Hg O2Names:Fact:6. Ca H2O -- Ca(OH)2 H2Names:Fact:7. CH4 O2 -- CO2 H2ONames:Fact:13
8. Na2O2 H2SO4 -- Na2SO4 H2O2Names:Fact:9. N2 H2 -- NH3Names:Fact:10. Al O2 -- Al2O3Names:Fact:11. KMnO4 -- K2O MnO O2Names:Fact:Brain Boggle chemBalancer3/default.htm1. F2 Al2O3 -- AlF3 O2Fact:2. C2H6 O2 -- CO H2OFact:3. NH3 O2 -- NO H2OFact:4. C5H12 O2 -- CO H2OFact:5. C8H18 O2 -- CO H2OFact:14
Name PeriodBalancing Chemical Equations: A Number SearchBalance each chemical reaction below. Find the string of coefficients for each reaction within thenumber search and circle it. Remember, no coefficient actually means “1”. See the example.4329322Example:334676064821272H2 604433780750129391406123706coefficient string: 212Clues1. Na Cl2NaCl2. Fe O2Fe2O33. KClO3KCl O24. NH3 O2NO H2O5. Na H2ONaOH H26. Fe H2OFe3O4 H27. Br2 CaI2CaBr2 I28. Ca(OH)2 H3PO4Ca3(PO4)2 H2O9. Co(OH)3 HNO3Co(NO3)3 H2O10. Al2(SO4)3 Ca3(PO4)2AlPO4 CaSO415
Balancing Equations Practice QuizDIRECTIONS: Write a number, even if it is a “1”, in the spaces to balance the equation. Do notleave any blank.1. Ca AlCl3CaCl2 Al2. Fe O2Fe2O33. ClF NH3NH4Cl NF3DIRECTIONS: Write the correct formulas under the word equation. Be sure to balance theequation.4. lead sulfuric acidplumbic sulfate hydrogen gas5. ferric chloride ammonium hydroxideferric hydroxide ammonium chloride16
Balancing Equations Race17
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TYPES OF CHEMICAL REACTIONSA. CompositionA BAB1. two elementsa binary compounda metal and a nonmetalwrite the metal first followed by the nonmetalcrisscross the charges derived from the periodic table to determine the formulaadd coefficients to balance the equationtwo nonmetalswrite the least electronegative element (the one farther away from fluorine)first followed by the other nonmetalthe least electronegative element has the represent the positive part of themolecule, so assign it a positive charge from the periodic tablei.e. thecolumn it is inassign a negative charge to the second nonmetal (just like you always do) andcrisscross the chargesadd coefficients to balance the equation2. metallic oxide watera base (metallic hydroxide)3. nonmetallic oxide wateran acidsince it is an acid, H 1 is the positive part of the compoundfor the negative part of the compound, write the “-ate” ion that exists between thenonmetal and oxygen (make sure to balance the formula)Balance the equation. IF the oxygens do not balance, adjust the number of oxygensin the acid to balance the equationi.e. change the polyatomic ion to the ite, per,or hypo formulaB. Decomposition ABA B1. binary compoundtwo elements2. basemetallic oxide water3. acidnonmetallic oxide watermake sure you have the correct formula for the acidwrite water as one of the productsbalance only the hydrogens by adding coefficientsadd subscripts to the nonmetal oxide formula to balance the equation (NOTE: this is agimmick that works; it is the only time you will add subscripts to balance an equation)4. metallic carbonatemetallic oxide carbon dioxide5. metallic chloratemetallic chloride oxygen gas6. hydrated saltsalt waterC. Single Replacement A BXB AX ; X AYY AX1. active metal (or H2) ionic compoundnew metal (or H2) ionic compoundwhen an active metal reacts with water, the metal replaces only one of the hydrogensin water, forming a base and hydrogen gas as the products. It is easy to see how thisoccurs if water is written HOH.2. active halogen ionic halidehalogen ionic compoundD. Double Replacement AX BYAY BX1. two soluble ionic compoundstwo new compounds, one of which must be an insolubleionic compound or a molecular compound19
Solubility Chartpositive ionnegative ionsodium, potassium, ammoniumnitrate, acetate, chloratesilver, mercury, leadcarbonate, phosphate, sulfide, hydroxide insolublechloride, bromide, iodidebarium, calcium, strontiumsolubleinsolublesulfateActivitySeries ilvergoldsolublesolubleActivitySeries ofHalogensfluorinechlorinebromineiodine20
Chemical Reactionssymbols used in chemical equationsSYMBOLEXPLANATIONused in place of a single arrow to indicate areversible reactiona reactant or product in the solid state; also used toindicate a precipitate(l)a reactant or product in the aqueous state dissolved in watera reactant or product in the gaseous statealternative to (g), but used only to indicate agaseous product orheatKI21
TYPES OF CHEMICAL REACTIONSA. COMPOSITION: A BABTYPES OF COMPOSTION REACTIONS:1.2 ELEMENTSA BINARY COMPOUNDA. METAL NONMETALMg Ca N2O2BINARY IONIC COMPOUND Write the metal first, then the nonmetal. Assign charges derived from the PT. Use the crisscross method to determine theformula for the binary ionic compound. B. NONMETAL NONMETALBINARY COVALENT COMPOUND H2 Br2Add coefficients to balance the equation.Write the least electronegative nonmetal first, thenthe second nonmetal. Assign the first nonmetal a positive charge equal tothe number of the column that it’s in. Assign a negative charge to the second nonmetaljust like you have always done.S O2 Use the crisscross method to determine the formulafor the binary molecular compound. Add coefficients to balance the equation.22
2.METALLIC OXIDE WATERA BASE (METALLIC HYDROXIDE)What is a metallic oxide?ExamplesWhat are some examples of a base?CaO H2ONa2O 3.H2O Write the metal first, then OH-. Assign a positive charge to the metal. Use the crisscross method to determine theformula for the metallic hydroxide. NONMETALLIC OXIDE WATERAdd coefficients to balance the equation.AN ACIDWhat is a nonmetallic oxide?Examples:What is an acid?Examples:P2O5 H2O Write H followed by the “ate” polyatomic ion thatexists between the nonmetal and oxygen. Use the crisscross method to balance the formula ofthe acid.SO2 H2O Balance all atoms except oxygen. If the oxygenatoms are not balanced, adjust the number ofoxygens in the acid formula to balance the equation(i.e. change the polyatomic ion to the ite form).23
Composition ReactionsNAME PERIODDirections: Predict the products of the following reactions and then balance the equations.1.Li I2 ------ 2.Mg N2 ------- 3.H2 N2 ------- 4.SO3 H2O ------ 5.Mn Cl2 ------ (manganese II)6.Cl2O3 H2O ------ 7.Sr S ------ 8.Pb Cl2 ------ (lead II)9.S O2 ------ 10. K Br2 ------ 11. I2 Cl2 ------ 12. P2 O5 H2O ------ 13. Fe O2 ------ (iron III)14. Cr2O3 H2O ------ 15. Ag O2 ------ 24
B. DECOMPOSITION: ABA BWHAT IS A DECOMPOSITION REACTION?TYPES OF DECOMPOSITION REACTIONS:1.BINARY COMPOUNDMgO2 ELEMENTS Separate the two elements that make upthe compound. (Remember the diatomic2.elements!) KClBASE METALLIC OXIDE WATER Ca(OH)2Balance the equation.Write the formula for water (always 1 of theproducts). Write the metal ion from the base with a chargederived from the PT.NaOH3.ACIDHClO4H2SO3 Write the oxide ion (O 2-). Balance the formula. Balance the equation.NONMETALLIC OXIDE WATER Write the formula for water (always 1 of theproducts. Balance the hydrogens by adding coefficients. Add subscripts to the nonmetal oxide formula tobalance the equation. (NOTE: this is a gimmickthat works; it is the ONLY time you will addsubscripts to balance an equation)25
4.METALLIC CARBONATEMETALLIC OXIDE CARBON DIOXIDEWHAT IS A METALLIC CARBONATE?EXAMPLES:Write the formula for carbon dioxide (always 1 CaCO3 of the products).Write the metal ion from the metallic carbonate with a charge derived from the PT.Na2CO35. METALLIC CHLORATE Write the oxide ion (O -2); balance the formula Balance the equation.METALLIC CHLORIDE OXYGEN GASWHAT IS A METALLIC CHLORATE?EXAMPLES:WHAT IS A METALLIC CHLORIDE?EXAMPLES:KClO3 Write the formula for oxygen gas (always 1 ofthe products). Write the metal ion from the metallic chloratewith a charge derived from the PT.Mg(ClO3)2 formula 6.HYDRATED SALTWrite the chloride ion (Cl -1); balance theBalance the equation.SALT WATERWHAT IS A HYDRATED SALT?BaCl2 2H2O CuSO4 5H2O Separate the hydrated salt into salt andwater.Keep the coefficients the same.SPECIAL DECOMPOSITION REACTION26
Decomposition ReactionsNAME PERIODDirections: Predict the products of the following reactions and then balance the equations.1. ZnCO3 ------ 2. Ba(ClO3)2 ------ 3. CaCO3 ------ 4. KClO3 ------ 5. H2CO3 ------ 6. Ba(OH)2 ------ 7. HgO ------ 8. NaCl ------ 9. H2SO4 ------ 10. Ag2O ------ 11. Fe(OH)3 ------ 12. PBr5 ------ 13. CuSO4 5H2O ------ 14. H3PO4 ------ 15. NiCO3 ------ (nickel II)27
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Chemical reactions called _ reactions give off heat. 5. Other reactions called _ reactions absorb heat and cool the immediate environment. 6. True or False. During all chemical reactions, a chemical change takes place that produces new substances with properties different than those of the original substances. .
Chemical Reactions Slide 3 / 142 Table of Contents: Chemical Reactions · Balancing Equations Click on the topic to go to that section · Types of Chemical Reactions · Oxidation-Reduction Reactions · Chemical Equations · Net Ionic Equations · Types of Oxidation-Reduction Reactions · Acid-Base Reactions · Precipitation Reactions
Lesson Overview Chemical Reactions and Enzymes Chemical Reactions and Enzymes. Lesson Overview Chemical Reactions and Enzymes Chemical Reactions A chemical reaction is a process that changes , or transforms, one set of chemicals into another by changing the
The Major Classes of Chemical Reactions. 4.6 Elements in Redox Reactions 4.1 The Role of Water as a Solvent 4.2 Writing Equations for Aqueous Ionic Reactions 4.3 Precipitation Reactions 4.4 Acid -Base Reactions. 4.5 Oxidation -Reduction (Redox) Reactions 4.7
Types of Reactions There are five main types of chemical reactions we will talk about: 1. Synthesis reactions 2. Decomposition reactions 3. Single displacement reactions 4. Double displacement reactions 5. Comb
C.P. Chemistry Test Unit 8 Study Guide Chemical Equations and Reactions Recognize evidence of chemical change. Identify the reactants and products in a chemical reaction. Represent chemical reactions with equations. Know what is represented by the symbols: s, l, g, and aq. Categorize chemical reactions by type (synthesis/combination, decomposition,
ii. acid–base neutralization reactions iii. oxidation–reduction or redox reactions. Q.3. What are the important aspects of redox reactions? Ans: Almost every element participate in redox reactions. The important aspects of redox reactions are as follows: i. Large number of natural, biological and industrial processes involve redox reactions .
Topic 8: Chemical Reactions Chemical Equations & Reactions (Chapter 8 in Modern Chemistry) Describing Chemical Reactions A chemical reaction is the process by which one or more substances are changed into one or more different substances. In any chemical reaction, the original substances are known as the
Graphic Symbols N Up 17R Stair direction symbol Indication arrows drawn with straight lines (not curved); must touch object Note Note Note North point to be placed on each floor plan, generally in lower right hand corner of drawings 111/ 2 T The symbols shown are those that seem to be the most common and acceptable, judged by the frequency of use by the architectural offices surveyed. This .
