Transcript Net Start Class


1. A chemical reaction is the process by which one or
more substances are changed into one or more
different substances.
2. A chemical equation represents a chemical reaction.
3. A correct chemical equation shows what changes
take place and the relative amounts of the various
elements and compounds involved in the reaction.
4. The original substances in the reaction are called
the reactants.
5. The substances that are formed in the reactions are
the products.
a. Example: Iron + Oxygen —> Iron (II) Oxide
b. Example: Hydrogen + Oxygen —>Water
6. The —> means yields, gives, or reacts with to
produce.

1. To shorten an equation, we use chemical
formulas to write chemical equations.
2. In a chemical equation, the —> separates
the reactant and the products.
3. A skeleton equation show just the
formulas for the reactants and products.
4. A catalyst is added to a reaction to speed
up the reaction.
5. A catalyst is neither a product or a
reactant so it is written over the —>.
Create flash cards. Quiz over the symbols on Wednesday

1. An equation that does not indicate the
quantity of the reactants needed to make
the product is called an unbalanced equation.
2. To balance the equation, the same number
of elements on both sides of the equation.
3. Use coefficients to balance the formulas.
4. You can not change the subscripts in the
formula.
Diatomic Molecules
H2 N2 F2 O2 I2 Cl2 Br2
No Fear of Having Iced Chocolate Brownies!
-An acronym to remember the 7 diatomic elements-
The number and type of all atoms must be the same in the
reactants and products.
 Metals
 Polyatomic
 Nonmetals
 Oxygen
 Hydrogen
Ions
3 minutes
Meaning
Separates 2 reactants or products
“yields” or “produces” indicates result of a reaction
A reactant or product in the solid state
A reactant or product in the liquid state
A reactant or product in aqueous solution (dissolved in water)
A reactant or product in the gaseous state
Symbol
+
7 minutes
1. __NaCl + __BeF2 --> __NaF + __BeCl2
2. __FeCl3 + __Be3(PO4)2 --> __BeCl2 + __FePO4
3. __AgNO3 + __LiOH --> __AgOH + __LiNO3
Remember:
Check for diatomic gases
Watch for Polyatomics
Balance Oxidation Numbers
Do not forget to use “MINOH”
7 minutes
4. __ Pb(NO3)2 + __ KI ---> __ PbI2 + __ KNO3
5. __Mg + __Mn2O3 --> __MgO + __Mn
6. calcium plus fluorine yields calcium fluoride.
Remember:
Check for diatomic gases
Watch for Polyatomics
Balance Oxidation Numbers
Do not forget to use “MINOH”
3 minutes
2. In the chemical equation below, identify the reactants, products, subscripts,
& coefficients
4 Fe + 3 O2
→ 2 Fe2O3
(s)
(g)
(s)
a. What are the reactant(s)?
b. What is the coefficient for Iron?
c. What are the product(s)?
d. # of moles of O2 =
e. # of atoms of Fe in 2 Fe2O3 =
f. Which reactants are solid(s)?=
3. Balance a chemical equation by changing coefficients/subscripts (choose one)

1. There are five types of chemical
reactions
a.
b.
c.
d.
e.

Synthesis
Decomposition
Single Displacement
Double Displacement
Combustion
2. Sometimes a reaction can fit into
more than one class of reaction.

1. Combination (Synthesis) reaction occur
when two or more substances combine to
form one new substance.
2. The product of a combination reaction is
always a compound.
3. Combination can be either element or
compounds.
a. element + element —> compound
b. compound + compound —> compound
Example: 2H2 + O2 —> 2H2O

1. Decomposition reaction occur when
substances breaks up into simpler
substances.
a. compound —> two or more compounds
or elements
b. Example: 2KClO3 —> 2KCl + 3O2
2. Most decompositions require energy in
the form of heat, electricity, or light.
3. Extreme decomposition reactions that
produce gaseous products and heat are
often the cause of explosions.

1. Single displacement reaction occur when
one element displace another in a compound.
a. element + compound —> element +
compound
b. Example: Cl2 + 2KBr —> 2KCl + Br2
2. In compounds metals will replace another
metal based on the activity of the single
metal.
3. Nonmetals can replace another nonmetal
from a compound.

1. Double displacement reaction occur when an
element in a compound trades place with another
element in another compounds.
a. compound + compound —> compound +
compound
b. Example: NaOH+ HCl —>NaCl + HOH (H2O)
2. Double Replacement reactions occur mainly
between ionic compounds.
3. The products can be a precipitate (solid), a
gas, or water.

1. Combustion occurs when a substance,
usually a hydrocarbon, burn in the presence
of oxygen.
a. hydrocarbon + oxygen —> carbon
dioxide + water
b. Example: CH4 + 2O2 —> CO2 +2H2O
2. For any clean combustion reaction, the
products will always be carbon dioxide (CO2)
and water.

1. To predict the product of a
reaction, you must determine which
type of reaction is occurring.
2. Not all reactions fall into the
five classes of reactions.

1. An aqueous solution is a compound dissolved in water.
2. For reaction taking place in water, it is customary to
write equation in ionic form (ions taking part in the reaction,
not spectators ions).
3. Ions that are not directly involved in a reaction are called
spectator ions.
4. A complete ionic equation show all the ions as free ions.
5. Spectator ions appear on both sides of the equation.
6. You can rewrite the equation leaving out the spectator ion
which is called the net ionic equation.
7. In writing balanced net ionic equations, you must also
balance the ionic charge to zero.
8. Use coefficients to balance the net ionic equation.

1. Mixing of two
aqueous
solutions can
result in the
formation of an
insoluble salt
called a
precipitate.
2. The
formation of
the precipitate
is predicted by
the using the
general
solubility rules.
Synthesis
Not on of the other types of reactions…
Decomposition
One reactant
Combustion
anything + oxygen
Next slide
Break it down one step
hydrocarbon + O2
CO2 + H2O
Could be synthesis
Single Replacement
element + ionic compound
Check activity!
Double Replacement
ionic compound + ionic compound
Ion swap
Check solubility!
Ion swap
metal + nonmetal
ionic compound
nonmetal(s) + nonmetal
simplest compound
metal oxide + water
metal hydroxide
nonmetal oxide + water
oxyacid
Simple
Synthesis
Specific
metal oxide + nonmetal oxide
ionic compound
Example C + O2 CO2
C + O O
General:

O C O
A + B  AB
Predict the products.
Na(s) + Cl2(g) 
Mg(s) + F2(g) 
Al(s) + F2(g) 
Synthesis: A synthesis reaction is when two
or more simple compounds combine to form
a more complicated one.
Predict the products.
Na(s) + Cl2(g)  NaCl(s)
Mg(s) + F2(g) 
MgF2(s)
Al(s) + F2(g)  AlF3(s)
Now, balance them.
Example: NaCl  Na + Cl2
Cl Na

General:
Cl
+
Na
AB  A + B
B2O3 
AlCl3 
Decomposition: A decomposition
reaction is the opposite of a synthesis
reaction - a complex molecule breaks
down to make simpler ones.
Example: Zn + CuCl2  ZnCl2 + Cu
Zn was oxidized
Went from neutral (0) to (+2)
Cu
Cl
+
Cl
Zn

Zn
Cl
+
Cu
Cl
Cu was reduced
Went from (+2) to Neutral (0)
General:
AB + C  AC + B
Write and balance the following single
replacement reaction equation:
Zn(s) + HCl(aq) 
Cu(s)+ Al(NO3)3(aq)
•
Single Replacement: This is when one
element trades places with another element
in a compound.
Activity Series
“Magic blue-earth”
Fe
+
FeCl2
CuCl2
+
Can Fe replace Cu? Yes
Zinc in nitric acid
Zn + 2HNO3
Zn(NO3)2
Can Zn replace H?
+ H2
Yes
NO REACTION
MgCl2
+
MgBr2
Br2
Can Br replace Cl?
+
No
General Form
A
+
BC
AC + B
Cl2
Cu
Li
Rb
K
Ba
Ca
Halogen Reactivity
Na
F2
Mg
Cl2
Al
Br2
Mn
I2
Zn
Cr
Fe
Ni
Sn
Pb
H2
Cu
Hg
Ag
Pt
Au
Element Reactivity
Ca
Foiled again –
Aluminum loses to Calcium
Li
Rb
K
Ba
Ca
Na
Mg
Al
Mn
Zn
Cr
Fe
Ni
Sn
Pb
H2
Cu
Hg
Ag
Pt
Au
Halogen Reactivity
F2
Cl2
Br2
I2
3 Mg
+ 2 AlCl3
2 Al
+ 3 MgCl2
Can magnesium replace aluminum? YES, magnesium is more reactive than aluminum.
Activity Series
Al
+
MgCl2
No reaction
Can aluminum replace magnesium? NO, aluminum is less reactive than magnesium.
Activity Series
MgCl2
+
Al
Therefore, no reaction will occur.
No reaction
Order of reactants
DOES NOT
determine how
they react.
The question we must ask is can the single element replace its counterpart?
metal replaces metal or nonmetal replaces nonmetal.
Write and balance the following single
replacement reaction equation:
Zn(s) + HCl(aq) 
ZnCl2 + H2(g)
• NaCl(s) + F2(g)  NaF(s) + Cl2(g)
• Al(s)+ Cu(NO3)2(aq) Cu(s)+ Al(NO3)3(aq)
Example: MgO + CaS MgS + CaO
Mg
+
O
General:
Ca
S

Mg
S
+
Ca
O
AB + CD  AD + CB

Think about it like “foil”ing in algebra, first
and last ions go together + inside ions go
together
Example:
AgNO3(aq) + NaCl(s)  AgCl(s) + NaNO3(aq)
Another example:
K2SO4(aq) + Ba(NO3)2(aq)  KNO3(aq) + BaSO4(s)
acetate
bromide
carbonate
chloride
chromate
hydroxide
iodide
nitrate
phosphate
sulfate
sulfide
TABLE OF SOLUBILITIES IN WATER
aluminum
ss
s
n
s
n
i
s
s
i
s
d
ammonium
s
s
s
s
s
s
s
s
s
s
s
barium
s
s
i
s
i
s
s
s
i
i
d
calcium
s
s
i
s
s
ss
s
s
i
ss
d
copper (II)
s
s
i
s
i
i
n
s
i
s
i
iron (II)
s
s
i
s
n
i
s
s
i
s
i
iron (III)
s
s
n
s
i
i
n
s
i
ss
d
lead
s
ss
i
ss
i
i
ss
s
i
i
i
magnesium
s
s
i
s
s
i
s
s
i
s
d
mercury (I)
ss
i
i
i
ss
n
i
s
i
ss
i
mercury (II)
s
ss
i
s
ss
i
i
s
i
d
i
potassium
s
s
s
s
s
s
s
s
s
s
s
silver
ss
i
i
i
ss
n
i
s
i
ss
i
sodium
s
s
s
s
s
s
s
s
s
s
s
zinc
s
s
i
s
s
i
s
s
i
s
i
Legend
i = insoluble
ss = slightly soluble
s = soluble
d = decomposes
n = not isolated
Solubility Rules
1.
Most nitrates are soluble.
2.
Most salts containing Group I ion and ammonium ion, NH4+, are soluble.
3.
Most chloride, bromide, and iodide salts are soluble, except Ag+, Pb2+
and Hg22+.
4.
Most sulfate salts are soluble, except BaSO4, PbSO4, Hg2SO4, and CaSO4.
5.
Most hydroxides except Group 1 and Ba(OH)2, Sr(OH)2, and Ca(OH)2 are
only slightly soluble.
6.
Most sulfides, carbonates, chromates, and phosphates are only slightly
soluble.
Predict the products.
5.
HCl(aq) + AgNO3(aq) 
CaCl2(aq) + Na3PO4(aq) 
Pb(NO3)2(aq) + BaCl2(aq) 
FeCl3(aq) + NaOH(aq) 
H2SO4(aq) + NaOH(aq) 
6.
KOH(aq) + CuSO4(aq) 
1.
2.
3.
4.
Double Replacement: This is when the
anions and cations of two different
molecules switch places, forming two
entirely different compounds.
Also known as Acid-base: This is a special kind of double
displacement reaction that takes place when an acid and
base react with each other. The H+ ion in the acid reacts with
the OH- ion in the base, causing the formation of water.
Generally, the product of this reaction is some ionic salt and
water:
HA + BOH ---> H2O + BA
One example of an acid-base reaction is the reaction of
hydrobromic acid (HBr) with sodium hydroxide:
HBr + NaOH ---> NaBr + H2O
Acid +
base --->
salt + water
Combustion reactions - a
hydrocarbon reacts with
oxygen gas.
This is also called burning!!!
In order to burn something
you need the 3 things in
the “fire triangle”:
1) Fuel (hydrocarbon)
2) Oxygen
3) Something to ignite the
reaction (spark)
In general:
CxHy + O2  CO2 + H2O
 Products are ALWAYS
carbon dioxide and water.
(although incomplete
burning does cause some
by-products like carbon
monoxide)
 Combustion is used to heat
homes and run automobiles
(octane, as in gasoline, is
C8H18)

Carbon
Hydrogen
Oxygen
Combustion reactions are harder to balance than any other
Reactions.
Example
C5H12 + O2  CO2 + H2O
Write the products and balance the following
combustion reaction:
C10H22 + O2 
Combustion: A combustion reaction is when
oxygen combines with another compound to
form water and carbon dioxide. These reactions
are exothermic, meaning they produce heat.
State the type & predict the products.
1.
2.
3.
4.
5.
BaCl2 + H2SO4 
C6H12 + O2 
Zn + CuSO4 
Cs + Br2 
FeCO3 
Oxidation-Reduction reactions
Redox reactions - transfer of electrons between species.
All the redox reactions have two parts:
Oxidation
Reduction
Involves 2 processes:
Oxidation = Loss of Electrons (LEO)
Na  Na+ + e
Oxidation Half-Reaction
Reduction = Gain of electrons (GER)
Cl2 + 2e  2Cl
Reduction Half-Reaction
Net reaction:
2Na + Cl2  2Na+ + 2Cl
› Oxidation & reduction always occur
together
› Can't have one without the other
Which species is being oxidized in the
following oxidation-reduction reaction?
Zn(s) + Pt2+(aq)  Pt(s) + Zn2+(aq)
A. Pt(s)
B. Zn2+(aq)
C. Pt2+(aq)
D. Zn(s)
E. None of these, as this is not a redox
reaction.
Oxidation numbers must add up to charge
on molecule, formula unit or ion.
2. Atoms of free elements have oxidation
numbers of zero.
3. Metals in Groups 1A, 2A, and Al have +1,
+2, and +3 oxidation numbers, respectively.
4. H & F in compounds have +1 & –1 oxidation
numbers, respectively.
5. Oxygen has –2 oxidation number in all
compounds but peroxides
1.
1.
Li2O
Li (2 atoms) × (+1) = +2 (Rule 3)
O (1 atom) × (–2) = –2 (Rule 5)
sum = 0 (Rule 1)
+2 –2 = 0 so the charges are balanced to zero
2.
CO2
C (1 atom) × (x) = x
O (2 atoms) × (–2) = –4 (Rule 5)
sum = 0 (Rule 1)
x  4 = 0 or x = +4
C is in +4 oxidation state
A redox reaction occurs when there is a
change in oxidation number.
Oxidation
› Increase in oxidation number
› e loss
Reduction
› Decrease in oxidation number
› e gain


Sometimes electron transferred in "formal"
O: decrease
reduction
sense.
C: increase
-4 +1
0
CH4 + 2O2
oxidation
+4 -2
+1 -2
CO2 + 2H2O
O: oxidation number decreases by 2
 reduction
C: oxidation number increases by 8
 oxidation

Identifying Reaction Types

A redox reaction must involve a change in oxidation number for two
of the elements involved in the reaction. The oxidized element
increases in oxidation number, while the reduced element
decreases in oxidation number.
Single-replacement reactions are redox reactions because two
different elements appear as free element (oxidation number of
zero) on one side of the equation and as part of a compound on
the other side. Therefore, its oxidation number must change.
Zn is oxidized from Zn0 to Zn2+ and the H is reduced from H+ to H0
Combustion reactions are redox reactions because elemental
oxygen (O 2 ) acts as the oxidizing agent and is itself reduced.
Most combination and decomposition reactions are redox reactions
since elements are usually transformed into compounds and viceversa. The thermite reaction involves ferric oxide and metallic
aluminum:





So what types of reactions are not redox reactions?
Double-replacement reactions such as the one below are
not redox reactions because ions are simply recombined
without any transfer of electrons.
Note that the oxidation numbers for each element remain
unchanged in the reaction.
 Acid-base reactions involve a transfer of a hydrogen ion
instead of an electron. Acid-base reactions, like the one
below, are also not redox reactions.


Again, the transfer of an H + ion leaves the oxidation
numbers unaffected. In summary, redox reactions can
always be recognized by a change in oxidation number
of two of the atoms in the reaction. Any reaction in which
no oxidation numbers change is not a redox reaction.
EXIT TICKET
Why is the Zn + HCl reaction a redox reaction?
Why is the sodium sulfate + barium nitrate
reaction not a redox reaction?
Does the transfer of H + affect oxidation numbers?
EXIT TICKET
EXIT TICKET
For the following equations predict the products, balance and identify the type of reaction.
______1. ____ Na + ____ MgBr2  ________ + _______
Type of reaction:_____________________________
______2. ____Na2CO3 + ____CuCl2  _______ + _______
Type of reaction:_____________________________
Remember:
Check for diatomic gases
Watch for Polyatomics
Balance Oxidation Numbers
Do not forget to use “MINOH”
Brad Pitts + Angelina Jolie
Beyonce + Jay-z
Ashton Kutcher and Mila Kunis
Will + Jada
George Clooney + Amal Alamuddin
Kim K + Kanye
A + B = AB
Taylor Swift dumps ???????
Ashton Kutcher dumps Demi Moore
Chris Rock dumps his wife
Kevin Hart dumps his wife
Khloe K dumps Lamar Odom
•AB = A + B
Brad/Jennifer + Angelina =
Brangelina + Jennifer out in the cold
J-Low/Marc Anthony + Casper Smart
=J-Low/Casper Smart + Marc
Anthony out in the cold
AB + C = AC + B
AB + C* = A + BC*
Rapper T’Pain/ GFA + Rapper Lil Wanye /
GFB Switch and become
Rapper T’Pain/GFB + Rapper Lil Wanye/GFA
TI and Tiny + Future and Ciara Switch and
become TI and Ciara + Future and Tiny
™
AB + CD = AD + CB
Amanda Bynes, Charlie Sheen, Amy
Winehouse and Lindsey Lohan
One big “hot” toxic flammable mess