Chemical Reactions Powerpoint
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Transcript Chemical Reactions Powerpoint
Types Of Chemical
Reactions
Objective
Distinguish between the 5 different types
of reactions
Predict the products of a reaction
Predict the physical states of products
5 Types of Reactions
Composition
Decomposition
Single Replacement
Double Replacement
Combustion
Composition Reactions
When two or more substances react to form a
single product
2 reactants → 1 product
A
+ X → AX
2H2
+ O2 → 2H2O
MgO
+ CO2 → MgCO3
Decomposition
Occurs when a compound is broken down into
simpler substances
Single reactant yields two or more products
(1 reactant → 2 products)
forms a common gas as a product; CO2, O2,
SO2, H2O
Decomposition Examples
AX
→ A+ X
2HgO
→ 2Hg + O
2
CaCO3
→ CaO + CO2
Single Replacement
One substance replaces another
A metal replaces a metal, if it is more active
A non-metal replaces a non-metal, if it is more
active
Single Replacement Examples
A and B are metals;
A + BX → AX + B
X and Y are non-metals
OR
Y + BX → BY + X
Mg
+ Zn(NO3)2 → Mg (NO3)2 + Zn
Cl2
+ 2 KBr → 2 KCl + Br2
Double Replacement
An exchange of partners
The metal replaces the metal or the non-metal
replaces the non-metal
AX
+ BY → AY + BX
Na2S
+ Cd(NO3)2 → 2NaNO3 + CdS
BaCl2
+ K2CO3 → BaCO3 + 2KCl
Combustion
An element or compound reacts with oxygen
Usually produces heat → Exothermic
Combustion of a hydrocarbon always produces
carbon dioxide and water
2
Mg + O2 →
2
CH3OH + 3 O2 → 2 CO2 + 4 H20 + heat
2 MgO + heat
Composition
Two elements or compounds combine to form a
single substance
A + X → AX
Fe + S → FeS
H2O + SO3 → H2SO4
5 Kinds of Decomposition
Reactions
Metallic Carbonates
Metallic Hydroxides
Metallic Chlorates
Oxy Acids
Oxides
Metallic Carbonates
CaCO3
Metal
→ CaO + CO2
oxide and carbon dioxide formed
Metallic Hydroxides
Many metallic hydroxides (OH-), when heated,
decompose into metallic oxides and water.
Ca(OH)2 → CaO + H 0
2
Metal oxide and water formed
Exceptions to the rule: NaOH and KOH
Metallic Chlorates
(ClO3-), when heated, decompose into
metallic chlorides and oxygen
2KClO3 → 2KCl + 3O2
metal chloride and oxygen formed
Oxy Acids
Some oxy acids, when heated, decompose
into nonmetallic oxides and water
Seltzer Water
H2CO3 → CO2 + H2O
Acid Rain
H2SO3 → SO2 + H2O
Oxides
Some oxides, when heated, decompose.
2HgO → 2Hg + O2
2Pb O2 → 2PbO + O2
4 Kinds of Single Replacement
Reactions
Metal w/ more active metal
Hydrogen in acids w/ more active metal
Hydrogen in water w/ by most active metals
Halogen w/ more active halogen
Metal w/ more active Metal
Replacement of a metal in a compound by a
more active metal (PCS Mazintl)
Zn + CuSO4 → ZnSO4 + Cu (s)
Zinc replaces the copper, therefore zinc is
more active
P.C.S. Mazintl
P potassium
C calcium
S sodium
M magnesium
a aluminum
z zinc
i iron
n nickel
t tin
l lead
HYDROGEN
Copper
Mercury
Silver
Activity of Halogens
Fluorine
Chlorine
Bromine
Iodine
More Active
Hydrogen in acids w/ more active
metals
Replacement of hydrogen, in acids, by metals
more active than hydrogen (PCS Mazintl)
Zn + H2SO4 → Zn SO4 + H2 (g)
The corresponding metallic compound and
hydrogen gas are formed
P.C.S. Mazintl
P potassium
C calcium
S sodium
M magnesium
a aluminum
z zinc
i iron
n nickel
t tin
l lead
HYDROGEN
Copper
Mercury
Silver
Activity of Halogens
Fluorine
Chlorine
Bromine
Iodine
More Active
Hydrogen in water w/ most active
metals
Replacement of hydrogen, in water, by the
most active metals. Which Metals?
All Group I and some of Group II
Ca + 2 H2O → Ca(OH)2 + H2 (g)
A hydroxide and hydrogen gas are formed
Halogen w/ more active halogen
Replacement of a halogen by a more active halogen
Cl2 + 2 KBr → 2 KCl + Br2
Br2 + 2 KI → 2 KBr + I2
MgBr2 + I2 → no reaction because Br is more active
than I, so I will not replace Br
The corresponding metallic compound and elemental
halogen are formed
P.C.S. Mazintl
P potassium
C calcium
S sodium
M magnesium
a aluminum
z zinc
i iron
n nickel
t tin
l lead
HYDROGEN
Copper
Mercury
Silver
Activity of Halogens
Fluorine
Chlorine
Bromine
Iodine
More Active
Activity Series of the elements
A + BX → AX + B
If A replaces B, then A is more active than B
If an element is above another element on the chart,
then it is more active, and will replace the lower
positioned element
All metals above hydrogen displace hydrogen from
hydrochloric acid or dilute sulfuric acid.
P.C.S. Mazintl
P potassium
C calcium
S sodium
M magnesium
a aluminum
z zinc
i iron
n nickel
t tin
l lead
HYDROGEN
Copper
Mercury
Silver
Activity of Halogens
Fluorine
Chlorine
Bromine
Iodine
More Active
Example
Zn (s) + CuSO4 (aq)→
P.C.S. Mazintl
P potassium
C calcium
S sodium
M magnesium
a aluminum
z zinc
i iron
n nickel
t tin
l lead
HYDROGEN
Copper
Mercury
Silver
Activity of Halogens
Fluorine
Chlorine
Bromine
Iodine
More Active
Example
Zn (s) + CuSO4 (aq)→ ZnSO4 (aq) + Cu (s)
Mg (s) + Zn(NO3)2 (aq) → Mg (NO3)2 (aq) + Zn (s)
Double Replacement
AX + BY → AY + BX
usually takes place in a solution of water
2 compounds → 2 different compounds
1 of these will not be soluble in water
In order for you to know if the reaction has occurred, a solid or gas
must form
1 product will typically be:
solid: precipitate
gas: CO2 SO2 NH3
Solubility Rules for Double
Dis(RE)placement Reactions
How to determine which product is the
precipitate
Na+
Will always be soluble in water.
+
K
Tells you what won’t precipitate, so
NH4+
assume the other one will
NO3
[
Examples
Pb(NO3)2 (aq) + KI (aq) → PbI2 (s)+ 2 KNO3 (aq)
Examples
CaCO3 + 2 HCl → CaCl2 + H2CO3
H2O + CO2
NaOH (aq) + KI (aq) →
NaI (aq) + KOH (aq)
→
no reaction because
both products are
soluble (aq)
Writing Molecular, Complete Ionic,
and Net Ionic Equations (7.7 Tro)
Molecular Equations: an equation
showing the complete neutral formulas for
every compound in the reaction.
AgNO3 (aq) + NaCl (aq)→ AgCl(s) + NaNO3 (aq)
Complete Ionic Equations
equations that show reactants and
products as they are actually present in
solution.
Ionic compounds dissociate (dissolve) in
water, so they are written as individual
ions…if the compound is soluble…check
your solubility rules
Complete Ionic Equation of:
AgNO3 (aq) + NaCl (aq) → AgCl(s) + NaNO3 (aq)
Spectator Ions:
ions in solution that appear unchanged on
both sides of the equation
Net Ionic Equation:
equations which show only the species
that actually participate in the reaction
Spectator ions are omitted from the net
ionic equation
Net Ionic Equation for:
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq) → AgCl(s) + Na+ (aq) + NO3-(aq)
Write the molecular, complete
ionic and net ionic equations for
lead (II) nitrate reacts with lithium chloride
Write the molecular, complete
ionic and net ionic equations for
Hydrobromic acid reacts with calcium hydroxide
END