Download Honors Chemistry Chapter 11 Student Notes

Honors Chemistry
Chapter 11 Note Packet
(student’s edition)
Chapter 11 problems:
Chapter 11 figures:
11.1
36, 40, 52, 54, 57, 67, 71, 72
All of the figures are important and Table 1
Describing Chemical Reactions

reactants
chemical equations describe
example – creation of hydrogen chloride:
H2
+

Cl2
Say:
other example - creation of sodium chloride:
Na
+

Cl2
Say:
Showing Phases in Chemical Reactions:
gas =
liquid =
solid =
aqueous
Ex1: NaCl(s) =
Ex2: NaCl(aq) =
Ex3: H2O(l) =
other symbols:
(not aqueous - redundant)
 (one arrow) =
reactions
 (2 arrows) =
reaction
 H = Change in
cat =
(a substance that speeds up a reaction without being
in the reaction)
ppt =
(solid - only found on
side)
Balancing Chemical Equations: truly a trial and error process if there ever was one
Helpful hints:
1. 1 atom at a time
2. Balance atoms that appear only 1X per side first
3. Balance
as whole units
4. Balance diatomic elements last
5. Save H + O for last
if this doesn’t succeed, try
everything (particularly with combustion)
Showing Energy Changes in Equations:
endothermic C
H is
C + heat
H is
A + B + heat
exothermic A + B
Interpreting Chemical Equation - what do chemical equations really mean anyway?
H2O
11.2

H2
+
O2
(not balanced)
H2O

H2
+
atoms

atoms
+
atoms
(equal)
g

g
+
g
(equal)
moles

+
mole
moles
O2
(equal)
(not equal - doesn’t have to)
Types of Chemical Reactions
5 types - synthesis, decomposition, combustion, single replacement, double replacement
remember - first you’ve got to find the right products, then you gotta balance
1. Synthesis ( direct combination ) - needs
to happen
general formula (element + element):
Ba
+
S

Ex2 Mg
+
Cl2

Ex3:

Ex4:
Al
+
3Cl2

Na
+
O2

Ex1:
2. Decomposition (analysis) - needs
Ex7:
+
B

AB





to happen (usually
general formula (molecule + element):
Ex5:

Ex6:
A
AB
FeCl3

+
HgO 

+
MgSO4. 7 H2O


)
A
+
B



+
(hydrate)
3. Combustion - the reaction of hydrocarbons and oxygen to yield
.
general formula (“CHO”):
Ex8:
combustion of CH4
Ex9:
combustion of C3H8
CxHy +
Ex10: combustion of C4H10
Ex11: combustion of C2H5OH
O2

and
CO2
+
H2O
4. Single Replacement - take place in
a) Type 1:
solutions and need
energy
ions switch
general formula (molecule + element):
AB
+

M
Ex12:
HI
Ex13:
AlCl3
Ex14:
Ca
b) Type 2:
+
Mg
MB
+
A

+
Ca
+

+
HOH 
+
+
ions switch
general formula (molecule + element):
AB
+
X

AX
+
F2

Ex15:
NaCl
+
Ex16:
BaS +
O2
B
+

+
5. Double Replacement - again - aqueous solution - little energy - usually forms one
soluble ionic product (aka - aqueous) and either a ppt,
water, or a gas that bubbles out of water
general formula (molecule + molecule):
AB
+
CD

CB
+
AD
Ex17:
FeCl3 +
NaOH

NaOH


+
Ex18:
H2SO4
+
NH4Cl
+
+
Ex19:

NaOH
NH3(g)
+
H2O(l)
+ NaCl(aq)
Hey, some reactions happen and some don’t.
For synthesis, combustion, and decomposition, we will assume they all
sufficient activation energy (Ea).
For single replacement, use the
Ex20:
Ex21:
Ex23:
!

Ca
+
Ca
+
Al
+
H2O

Al
+
H(OH)

+
HI

Ex22:
Al
Cu
+
given
H2O
H(OH) 
+
+

HI
Rules for the single replacement activity series:
1.
2.
3.
4.
Any single element above an element in a compound will
it.
The top 5 elements react with
.
Metals above H react with
(molecules that start with H – not water).
The nonmetal reactivity series is
...
For double replacement reactions, use a solubility table and the following rules:
1. If one of the products formed is water, the reaction
.
2. If a gas is formed, the reaction
.
3. If an insoluble product forms (
), the reaction
(actually a
reaction may happen when two soluble products form, but it doesn’t go to
completion and is not directly observable).
Ex24:
Na2CrO4
+
Ex25:
FeCl3
+
KCl

KOH 
Note: precipitate symbols include
+
11.3
Reactions in Aqueous Solution
Ions in
solutions for aqueous solutions.
Ionic compounds are
.
When you put them in water, they
Ex1:
NaBr(s) +
Ex2:
MgCl2(s)
H2O(l)
+
H2O(l)
:


Also happens with some molecular substances - particularly
Ex3:
HCl(g)
+
Ex4:
H2CrO4(s)
H2O(l)

:

H2O(l) 
+
Writing Ionic Equations
so far we’ve looked at molecular equations
now it’s time for ionic equations - show what happens to the ions in a reaction
Ex1:
(“molecular” equation)
Fe(s)
+
HF(aq)

(total ionic)
(net ionic)
spectator ion =
Spectator ions are ions that undergo
in a chemical reaction.
Ex2:
(“molecular” equation)
H2SO4(aq)
+
NaOH(aq)

(total ionic)
(net ionic)
spectator ions =
Conservation of Charge - charges must
NIB
in a chemical reaction.
Solubility Trends
Cations -
very soluble very insoluble-
Anions -
very soluble for monotomics
very insoluble
sulfides
general trend:
As size decreases, solubility
.