Unit 5 Lesson 3 – Single and Double Replacement Reactions Demos It is Eggothermic

Single-Replacement Reactions A single element and a compound become a different element and a different compound. A + BX  AX + B Examples Zn + H2SO4  ZnSO4 + H2 2 NaBr + Cl2  2 NaCl + Br2 Video Link

Single Replacement The more reactive element replaces the less reactive Fe + CuSO4  FeSO4 + Cu Mg + NaBr  no rxn Single-replacement reactions only work if the single element is more reactive than the element in the compound. Check the metal reactivity chart. Fe + BaSO4  NR

Halogen-Halogen Replacement Look at activity series for halogens (page 7) If a halogen is higher (more reactive) it will replace another halogen Example: CaCl2 + F2  CaF2 + Cl2 CaF2 + Cl2  No rxn

Examples AgNO3 + Mg  Br2 + MgCl2  FeI3 + K  Remember: balancing happens AFTER you have predicted the products!

Double-Replacement Reactions 2 compounds become 2 different compounds AX + BY  AY + BX Video Link Examples HNO3 + NaOH  NaNO3 + H2O MgCl2 + 2NaOH  2NaCl + Mg(OH)2

Phase Notations solid (s) liquid (l) gas (g) aqueous (aq) Use the solubility chart to determine if a compound is aqueous (soluble in water).

Double Replacement If reactants are two compounds switch the ions to form two different compounds. AgNO3(aq) + NaCl(aq)  AgCl(s) + NaNO3(aq)

HCl (aq) + NaOH (aq)  NaCl (aq) + H2O (l) Note that the reaction must form a solid, gas, or water to occur BaCl2(aq) + KNO3(aq)  Ba(NO3)2(aq) + KCl(aq) So . . . BaCl2(aq) + KNO3(aq)  NR

Using the Solubility Chart If a compound is “insoluble” it will not dissolve in water If a compound is “soluble” it will dissolve in water If it is an exception on the solubility side, it is insoluble If it is an exception on the insoluble side, it is soluble

Determine if the following will dissolve in H2O (NH4)3PO4 Ba(OH)2 MgF2 MgCO3 Yes - soluble Yes – soluble, barium is an exception No – insoluble, group IIA is an exception No - insoluble

Practice Problems FeCl3 (aq) + Na3PO4 (aq)  AgF (aq) + KNO3 (aq)  AgNO3 (aq) + NaCl (aq) 

Testing for Common Products Oxygen: A glowing splint will burst into flame in pure oxygen. Hydrogen: A lighted splint inserted into an inverted test tube full of Hydrogen (H2 is lighter than air hence the inverted tube), will produce a 'squeaky' 'POP'! as it ignites. CO2: CO2 will turn lime water cloudy. Also, a test tube full of CO2 (not inverted as it's heavier than air) will extinguish a burning splint inserted into it. The standard test for water is to use cobalt (II) chloride paper .This is paper soaked in cobalt(II) chloride (CoCl2) solution. It turns from blue to pink upon exposure to water.