<p> Types of Reactions</p><p>(1) Single displacement - a reaction in which one element displaces another in a compound.</p><p>M1 + MNm --- M + M1Nm Nm1 + MNm -- Nm + MNm1 element + compound --- element + compound</p><p>The element, which displaces another in a compound, must be more active (reactive) than the one it is replacing.</p><p>In order to determine if the reaction will take place, you must consult an activity series. </p><p>There are separate lists for metals and nonmetals. Examples:</p><p>Cl2 + 2 KBr -- KCl + Br2 Ca + Mg2O -- CaO + 2 Mg Li2O + Na -- no rxn</p><p>(2) Double displacement – a reaction in which the positive and negative portions of two compounds are interchanged.</p><p>MNm + M1Nm1 --- MNm1 + M1Nm compound + compound -- compound + compound</p><p>Examples: PbCl2 + Li2SO4 --- 2 LiCl + PbSO4 ZnBr2 + 2 AgNO3 -- Zn(NO3)2 + 2 AgBr BaCl2 + KIO3 -- Ba(IO3)2 + 2 KCl</p><p>NOTE: When writing the formula for a compound the ions must have an opposite charge and the sum of the charges must equal zero. (3) Decomposition – a reaction where a substance breaks into simpler substances when energy is applied.</p><p>A -- B + C + D</p><p> compound -- elements or compounds</p><p>There are decomposition patterns that must be followed to correctly predict the products of a decomposition reaction. Decomposition Patterns</p><p>MNm -- M + Nm NH4NmO -- NH3 + HNmO NH4Nm -- NH3 + HNm * NH4NO3 -- H2O + N2O * NH4NO2 -- H2O + N2 MSO4 -- MO + SO2 + O2 MSO3 -- MO + SO2 MPO4 -- MO + P2O5 MPO3 -- MO + P2O3 MCO3 -- MO + CO2 MSiO3 -- MO + SiO2 MAsO4 -- MO + As2O5 MClO3 -- MCl + O2 MOH -- MO + H2O MNO3 -- MO + NO2 + O2 * KNO3 -- KNO2 + O2 * NaNO3 -- NaNO2 + O2</p><p>* = exception Examples:</p><p>CdCO3 -- CdO + CO2 Pb(OH)2 -- PbO + H2O</p><p>(4) Synthesis – a reaction in which two or more substance combine to form one new substance. </p><p>B + C + D -- A element or + element or -- compound compound compound </p><p>Synthesis patterns are the reverse of decomposition patterns.</p><p>Example: MO + H2O -- MOH M + Nm -- MNm</p><p>When writing a formula, do not forget that the overall charge on a compound must equal zero (be sure to consider subscripts). Examples: NH3 + HCl -- NH4Cl CaO + SiO2 -- CaSiO3 2 H2 + O2 -- 2 H2O</p><p>Substitute symbols for names, predict the products, and balance. </p><p>(1) copper (II) carbonate -- CuCO3(s) -- CuO(s) + CO2(g) (decomposition)</p><p>(2) copper (I) + sulfur -- 2 Cu(s) + S(s) -- Cu2S(s) (synthesis)</p><p>(3) silver nitrate + sulfuric acid -- 2 AgNO3(aq) + H2SO4(aq) -- Ag2SO4(s) + 2 HNO3 (double displacement) Practice the following:</p><p>(1) sulfuric acid -- (2) chromium(II) + hydrochloric acid -- (3) ammonium nitrate -- (4) sodium + oxygen -- (5) calcium hydroxide + sulfuric acid -- (6) copper(II) + silver nitrate --</p><p>Solutions to practice:</p><p>(1) sulfuric acid -- 2 H2SO4(aq) -- 2 H2O(l) + 2 SO2(g) + O2(g)</p><p>(2) chromium(II) + hydrochloric acid -- Cr(s) + 2 HCl(l) -- CrCl2(aq) + H2(g)</p><p>(3) ammonium nitrate -- NH4NO3(s) -- 2 H2O(l) + N2O(g)</p><p>(4) sodium + oxygen -- 4 Na(s) + O2(g) -- 2 Na2O(s) (5) calcium hydroxide + sulfuric acid -- Ca(OH)2(aq) + H2SO4(aq) -- CaSO4(s) + 2 H2O(l)</p><p>(6) copper(II) + silver nitrate -- Cu(s) + 2 AgNO3(aq) -- 2 Ag(s) + Cu(NO3)2(aq) Mass – Mass Relationships</p><p>Problem: How much reactant is needed to react with a specific amount of another reactant? How much product can be expected from a specific mass of reactant?</p><p>We use balanced equations to solve problems involving a chemical reaction. Calculations such as these are called mass-mass problems.</p><p>Mass-mass problems involve finding the mass of one substance from the given mass of another substance.</p><p>Example: How many grams of silver chloride can be produced from the reaction of 17.0 g of silver nitrate with excess sodium chloride?</p><p>(1) Write an equation and balance. AgNO3(aq) + NaCl(aq) --AgCl(s) + NaNO3(aq) 17.0 g (2) Find the number of moles of the given substance and the required substance.</p><p>(3) Use the balanced equation to determine the ratio of the moles or required substance to moles of a given substance.</p><p>NOTE: The coefficients in a balanced equation indicate the number of moles of reactants used and products produced in a chemical reaction. </p><p>(4) Express the moles of required substance in terms of grams. Example: How many grams of Cu2S could be produced from 9.9 g of CuCl reacting with an excess of H2S gas?</p><p>Example: How many grams of calcium hydroxide will be needed to react completely with 10 grams of phosphoric acid? Mass-Mass Problems</p><p>(1) Given the following equation:</p><p>2 KClO3 -- 2 KCl + 3 O2</p><p>How many moles of O2 can be produced by letting 12.00 moles of KClO3 react? </p><p>(2) Given the equation:</p><p>2 K + Cl2 -- 2 KCl</p><p>How many grams of KCl are produced from 2.50 g of K and excess Cl2? From 1.00 g and excess K? (3) Given the equation:</p><p>Na2O + H2O -- 2 NaOH</p><p>How many grams of NaOH are produced 2 from 1.20 x 10 grams of Na2O? How many grams of Na2O are required to produce 1.60 x 102 grams of NaOH?</p><p>(4) Given the following equation:</p><p>Cu + 2 AgNO3 -- Cu(NO3)2 + 2 Ag</p><p>How many moles of Cu are needed to react with 3.50 moles of AgNO3? If 89.5 g of Ag were produced, how many grams of Cu reacted?</p>