Chemical Reactions Produce New Substances With New .

CLASSIFICATION OF EQUATIONS WORKSHEETChemical reactions produce new substances with new properties. The starting materials ina chemical reaction are called reactants while the materials that are formed are called products.When we write an equation we put an arrow in the middle between the reactants and the products; thisarrow is read as yields.Example:Example:Ba(NO3)2 H2SO4 --- BaSO4 2 HNO3The names of the reactants are:The names of the products are:2 Al 3 S --- Al2S3The names of the reactants are:The name of the product is:In order to help students recognize patterns and be able to predict the products of chemicalreactions we classify most chemical reactions as one of four common types of reaction--composition,decomposition, single replacement and double replacement.In composition reactions elements combine to form a compound; or, in some cases, simplecompounds combine to form a more complex compound.EXAMPLES:2 Na S --- Na2SThe names of the reactants are :The name of the product is:H2O SO2 --- H2SO3The names of the reactants are :The name of the product is:

In decomposition reactions compounds are broken apart to form elements; or, in some cases, complexcompounds are decomposed to form simpler compounds.EXAMPLES:2 Al2O3 --- 4 Al 3 O2The name of the reactant is:The names of the products are:H2CO3--- H2O CO2The name of the reactant is:The names of the products are:In single replacement reactions one element takes the place of a second element in a compound.EXAMPLES:Mg 2 AgNO3 --- Mg(NO3)2 2 AgThe names of the reactants are:The names of the products are:Which element was replaced?Which element did the replacing?Cl2 CaI2 --- CaCl2 I2The names of the reactants are:The names of the products are:Which element was replaced?Which element did the replacing?

In double replacement reactions two compounds react with each other--the positive ion of onecompound combines with the negative ion of the second compound and vice versa.Examples:MgCl2 2 AgNO3 --- Mg(NO3)2 2 AgClThe names of the reactants are:The names of the products are:Al(OH)3 3 HNO3 --- Al(NO3)3 3 HOHThe names of the reactants are:The names of the products are:Classify each of the following reactions as composition, decomposition, single replacement ordouble replacement.1. Ba Cl2 --- BaCl22. Zn Cu(NO3)2 --- Zn(NO3)2 Cu3. 2 Ga 3 S --- Ga2S34. 2 NaOH H2SO4 --- Na2SO4 2 HOH5. 2 K 2 HOH --- 2 KOH H26. 2 H2O --- 2 H2 O27. 4 Li O2 --- 2 Li2O8. BaO2 H2SO4 --- BaSO4 H2O29. Br2 2 NaI --- 2 NaBr I210. CaCO3 --- CaO CO2

(You will notice that several elements had a subscript 2 after them in the above equations. There areseven elements that exist as diatomic molecules when they are not in compounds. The sevenelements are: hydrogen-H2, nitrogen-N2, oxygen-O2, fluorine-F2, chlorine-Cl2, bromine-Br2, andiodine-I2. These elements DO NOT have to be in twos in compounds--you continue to write theformulas for compounds just as you always have. They are in twos only when they are elemental.)When a chemical reaction occurs it must obey the Law of Conservation of Matter--matter isneither created nor destroyed in an ordinary chemical reaction. That means that for any elementin the reaction there must be the same number of atoms on each side of the arrow. These atoms are indifferent combinations or groupings but you must not create nor destroy atoms. (It is very much likeshuffling and dealing cards--you don't create or destroy cards, you just change the combinations.) Abalanced chemical equation obeys the law of conservation of matter--the equation is not true andhas no meaning until it is balanced. We balance equations by inserting coefficients in front of theformulas--DO NOT CHANGE THE FORMULAS! (We have spent weeks learning to write correctformulas--we don't abandon all of that when we start to balance equations.)EXAMPLES: Zn HCl --- ZnCl2 H2 ----not balancedZn 2 HCl --- ZnCl2 H2 ----balancedSb O2 --- Sb2O34 Sb 3 O2 --- 2 Sb2O3----not balanced----balanced

Classify each of the following reactions as composition, decomposition, single replacement or doublereplacement. Then balance each of the equations.(Note: when you have polyatomic ions they may usually be balanced as a group; only when the ionis broken apart do you have to look at individual atoms within the group.)1.K S --- K2S2.Sb Cl2 --- 3.Cd AgNO3 --- 4.Al2O3 --- 5.Al 6.Mg(OH)2 7.Fe O2 --- 8.Li HOH --- 9.MgCO3 --- 10.CsClO3 --- 11.HgO --- 12.Hg2(NO3)2 13.Ga 14.Ca(OH)2 15.Pb(C2H3O2)2 SbCl3Cd(NO3)2 Al F2 --- AgO2AlF3HNO3 --- Mg(NO3)2 HOHFe2O3LiOH MgO CO2CsCl Hg H2O2O2NaCl --- HCl --- GaCl3 (NH4)2C2O4 --- K2SO4 --- Hg2Cl2 NaNO3H2CaC2O4 NH4OHPbSO4 KC2H3O2

Chemistry Equations – Worksheet #1NameWe have learned symbols for elements and to write formulas for compounds. Now we must learn towrite equations to represent chemical reactions. Chemical reactions obey the Law of Conservation of Matter:matter is neither created nor destroyed during a chemical reaction. This means that in any chemical reaction wesimply rearrange the atoms much like shuffling of cards rearranges the cards but does not change the wholenumber of each type of card present. Because reactions obey the Law of Conservation of Matter, equationsmust be balanced: that is, the total number of atoms of each element must be the same on each side of theequation. You do not have a chemical equation until it is balanced. Balancing is done by insertingcoefficients for the terms in the equation; you never balance an equation by changing subscripts.Many chemical reactions fit into one of four general classes: composition (or synthesis),decomposition (or analysis), single replacement (or simple replacement), and double replacement (ormetathetical). If composition, elements combine to make a compound, while in decomposition; a compound isbroken apart into its elements or simpler compounds. In single replacement, one element takes the place ofanother element in a compound, while in double displacement; the elements in two compounds switch partnerswith each other. Examples of the four types are:Composition:Decomposition:Single Replacement:Double Replacement:2Al 3S Al2S32H2O 2H2 O2orH2CO3 H2O CO2Zn 2AgNO3 Zn(NO3)2 2Ag or Cl2 2NaBr 2NaCl Br2Pb(NO3)2 Na2So4 PbSO4 2NaNO3Balance the following by inserting the appropriate coefficient for each term. Also write the type of reaction inthe blank to the left. 1.Mg O2MgO2.AgNO3 3.N2 H2 NH34.Al O2 Al2O35.Na 6.NaOH 7.Al2(SO4)3 8.HgO9.Ba(OH)210.P4 11.Al 12.Cl213.Ba(OH)2 14.Ca(C2H3O2)2 15.NaClO3 BaCl2HOH NaOH H2SO4 Hg HNO3O2 CuSO4 H2 HOHAl(OH)3 CaSO4O2 Ba(NO3)2 HOHP4O10 NaI Ba(NO3)2Na2SO4 Ca(OH)2 AgCl Al2(SO4)3NaClHNO3 K2C2O4 NaCl CuI2Ba(NO3)2CaC2O4 O2 HOHKC2H3O2

Chemistry Equations – Worksheet #2NameChemical reactions always obey the Law of Conservation of Matter. Equations represent chemicalreactions, but the following equations are not yet complete – they must be balanced before they are trulyequations. Once you insert the correct coefficients the equations are balanced and obey the Law ofConservation of Matter and then they describe chemical reactions. You may only use coefficients to balancethe equations; you never change the subscripts, which are needed to give the correct formulas.The materials on the left of the equations are called reactants; the materials on the right side of theequation are called products. The arrow in the equations is read as yields. Notice that many of the equationsinvolve the seven elements that exist as diatomic molecules when they are pure elements: H2, N2, O2, F2, Cl2Br2, and I2. They do not exist in multiples of two in compounds – only when alone.Insert coefficients to balance the following equations and classify the reactions in terms of type.1.AgNO3 ZnCl2 AgCl Zn(NO3)22.FeCl3 NaOH Fe(OH)3 NaCl3.Al4.P45.K6.Ba(C2H3O2)2 7.Zn 8.Sb9.KClO3 10.Pb(NO3)2 11.Fe2O312.H213.NaOH 14.SO2 15.Al2O316.Fe(ClO3)317.CaCO318.KOH 19.H2O2 20.CaCO3 H2SO4 O2Al2(SO4)3 KOH (NH4)2SO4 HClO2 PbCrO4 Fe O2 H2O2NaNO3CO2H2OH2SO4 DCNH4C2H3O2Sb2O5O2 BaSO4 Na2CrO4 CH2ZnCl2 KCl H2P4O6HOH Na2SO4 HOHSO3Al O2NaSCN CaO Fe(SCN)3HCl NaClO3CO2H3PO4 H2O K2HPO4 HOHO2CaCl2 H2O CO2

Classroom WorksheetVocabulary and EquationsNameAnswer the following questions based upon your notes or upon the information given in the paragraphsfound at the top of the equations writing sheets. It is important to be extremely familiar with the terms andinformation that follow in order to successfully write correct chemical equations.1. Chemical symbols represent .2. Chemical formulas represent .3. The charges that you use to help you write the correct formulas are called .4. The small numbers that you insert when you write formulas are called .5. The total charge on any compound is .6. Define “polyatomic ions”, that is, tell what they are and how they behave.7. Why can’t polyatomic ions ever stand-alone? .8. What is true of the oxidation number of all metal ions? .9. Positive ions are called .10. Negative ions are called .11. Compounds that have names that end with the suffix “-ide” are .12. Give the seven common metals that form ions with two different charges and given the two charges of eachmetal:13. What ion is common to all acids?14. Binary acids have names that start with the prefix “ ” and end with the suffix “ ”15. Ternary acids containing an “-ate” polyatomic ion are named with the suffix “ ”.16. Ternary acids containing a “per—ate” polyatomic ion are named with the suffix “ ”.17. Ternary acids containing an “-ite” polyatomic ion are named with the suffix “ ”.18. Ternary acids containing a “hypo—ite” polyatomic ion are named “ --- ”.19. Give the names and formulas for the six common acids referred to below:a. stomach acid or muriatic acidb. battery acidc. the acid in vinegard. the acid in carbonated beveragese. the acid flavoring in colasf. the acid that turns protein yellow

1. Write the formulas for:Perchloric acid, chloric acid,chlorous acid, hypochlorous acid, and hydrochloric acid2. Chemical equations represent .3. The starting materials in an equation are called the .4. The arrow in an equation is read as .5. The ending materials in an equation are called the .6. The numbers we insert to balance an equation are called the .7. A triangle over the arrow in an equation means .8. DC over the arrow in an equation means .9. A word that means to decompose a compound by electricity is .10. The word molten means .11. We must balance equations because “matter is neither created nor destroyed in an ordinary chemicalreaction”. This statement is known as the .12. Write formulas for the molecules of the seven elements that exist in diatomic molecules:.13. Name the four general types of chemical reactions:.14. A metathetical reaction is another name for a reaction.15. An insoluble compound formed during a chemical reaction is called a .16. When carbonic acid forms as a product it decomposes to give .17. Burning means chemical combination with so you must add on the left.18. Another word that means burning is .19. Our common fuels are called and contain the elements and .20. The complete combustion of a hydrocarbon produces energy plus and .21. The three steps involved in writing chemical equations are:1. .2. .1. .