1. Chemical Reactions
Chapter 11

2. Describing chemical change
word equations
reactants  products
law of conservation of mass
EX: iron + oxygen  iron (III) oxide
EX: hydrogen peroxide  water + oxygen
EX: methane + oxygen  carbon dioxide + water

3. Describing chemical change
Chemical equations
Fe(s) + O2(g)  Fe2O3 (s)
s – solid; l – liquid; g – gas; aq – aqueous solution
catalysts listed above arrow

4. Describing chemical change
balancing equations - advice
numbers in front = coefficients
CAN’T change subscripts
number of element on one side = other side
if polyatomic is unchanged, count it as a whole
try to balance everything BUT hydrogens, oxygens 1st
double check when completed
make sure it’s reduced
combustion reactions are harder

5. Practice writing and balancing
EX: silver nitrate + hydrosulfuric acid yields silver sulfide + nitric acid
EX: manganese (IV) oxide + hydrochloric acid yields manganese (II) chloride + water + chlorine gas
EX: zinc hydroxide + phosphoric acid yields zinc phosphate + water

6. Practice writing and balancing
EX: hydrogen gas + sulfur yields hydrogen sulfide
EX: iron (III) chloride + calcium hydroxide yields iron (III) hydroxide + calcium chloride
Do problems 1 – 6, 9 – 11; pp

7. Types of chemical reactions
Single replacement
EX: Mg + ZnCl2  Zn + MgCl2
EX: Br2 + 2AgI  I2 + 2AgBr

8. Types of chemical reactions
Double replacement
EX: AgNO3 + H2SO4  HNO3 + Ag2SO4
EX: NaOH + HCl  H2O + NaCl

9. Types of chemical reactions
Synthesis/Combination
2K + Cl2  2KCl
2S + 3O2  2SO3
N2 + 3H2  2NH3

10. Types of chemical reactions
Decomposition
2NaHCO3  CO2 + H2O + Na2CO3
2NaBr  2Na + Br2

11. Types of chemical reactions
Combustion – incomplete (CO) or complete (CO2)
C6H12O6 completely combusts.
C6H12O6 + 6O2  6H2O + 6CO2
Ethane (C2H6) incompletely combusts.
2C2H6 + 5O2  4CO + 6H2O

12. Predicting Solubility
A) All common salts of the Group 1 elements and
ammonium ion are soluble. (column 1 w/ 17)
B) All common acetates and nitrates are soluble.
C) All binary compounds of Group 17 elements (other than F) with metals are soluble except those of silver, mercury (I), and lead.
D) All sulfates are soluble except those of barium,
strontium, lead, calcium, silver, and mercury.
E) Except for those in Rule A, carbonates, hydroxides, oxides, sulfides, and phosphates are insoluble.

13. Predicting Solubility
EX: BaSO4
EX: Pb(NO3)2
EX: (NH4)2S
EX: CaS
EX: AgF
EX: Ca(C2H3O2)2
EX: NaCl
EX: MgO

14. Net Ionic Equations AgNO3(aq) + NaCl (aq)  AgCl (s) + NaNO3(aq)
what are the ions in the aqueous state?
Ag+1 (aq) + NO3 -1(aq) + Na+1 (aq) + Cl-1 (aq)  AgCl(s) + Na+1 (aq) + NO3 -1(aq)
Eliminate the aqueous redundancy on both sides; spectator ions – ions not directly involved in the reaction (cancelled out)
Ag+1 (aq) + Cl-1 (aq)  AgCl(s)
Balance charge, then elements

15. Net Ionic Equations Pb (s) + AgNO3 (aq)  Ag (s) + Pb(NO3)2 (aq)
ANS: Pb(s) + 2Ag+1(aq)  2Ag(s) + Pb+2(aq)