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

2. 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

4. 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

5. 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

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

7. 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

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

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

11. 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

12. 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

13. 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

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

15. 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.