Download Chapter 11 * Chemical Reactions

Chapter 11 – Chemical Reactions
• There are many types of chemical
reactions. We will study 5 of these. By
being able to identify the type of
chemical reaction that will occur, one
can predict the products of a chemical
reaction.
Chemical Reactions
• Chemical equations
• In chemistry, it is useful to write the
chemical formulas of the reactants and
products.
• An arrow is placed between them to
show the direction of the chemical
reaction.
Reactants (state)  Products (state)
Chemical Reactions
• Chemical equations
• Chemical formulas are used along with
the state of the substance written as a
subscript in parenthesis.
• A ‘+’ sign is placed between each
reactant and each product to show if
multiple substances are either reactants
or products.
H2 (g) + O2 (g)  H2O (g)
Chemical Reactions
• Chemical equations
• An (s) indicates that the substance is in
the solid state.
• A (l) indicates that the substance is in the
liquid state.
• A (g) indicated that the substance is in
the gaseous state.
• An (aq) indicates that the substance is in
the aqueous state or dissolved state.
H2 (g) + O2 (g)  H2O (g)
Chemical Reactions
• Chemical equations
• Write the chemical equation when iron
metal reacts with oxygen gas to produce
rust, iron (III) oxide.
Fe (s) + O2 (g)  Fe2O3 (s)
Chemical Reactions
• Chemical equations
• Balancing Chemical Equations
• According to the Law of Conservation of
Mass, the number of atoms on the reactant
side of the equation must equal the
number of atoms on the product side.
• We can adjust the number of atoms on
each side of the equation by placing
coefficients in front of each substance.
4Fe (s) + 3O2 (g)  2Fe2O3 (s)
Chemical Reactions
• Chemical equations
• Balancing Chemical Equations
__Na (s) + __CaCl2 (aq)  __NaCl (aq) + __Ca(s)
__Pb(NO3)2 (aq) + __KI (aq)  __KNO3 (aq) + __PbI2(s)
Chemical Reactions
• Chemical equations
• Write the chemical equation when zinc
metal reacts with aqueous silver nitrate
to produce silver metal and aqueous zinc
nitrate.
Chemical Reactions
• Chemical equations
• Write the chemical equation when
aqueous potassium iodide reacts with
aqueous lead (II) nitrate to produce
aqueous potassium nitrate and solid
lead (II) iodide.
Chemical Reactions
• 5 Types of Chemical Reactions
• Synthesis (Combination) Reactions – 2
particles combine to form 1 larger
particle.
A + B  AxBy
Na (s) + O2 (g)  Na2O (s)
Chemical Reactions
• 5 Types of Chemical Reactions
• Synthesis (Combination) Reactions –
Predict the products in following the
chemical reaction;
Al (s) + O2 (g) 
Chemical Reactions
• 5 Types of Chemical Reactions
• Decomposition Reactions – 1 particle
splits into 2 smaller particles.
AxBy  A + B
H2CO3 (aq)  H2O (l) + CO2 (g)
Chemical Reactions
• 5 Types of Chemical Reactions
• Decomposition Reactions – Predict the
products of the chemical reaction when
sodium chloride is heated until is
decomposes.
NaCl (s) 
Chemical Reactions
• 5 Types of Chemical Reactions
• Combustion Reactions – An element or
molecule reacts with oxygen gas that
produces products which have oxygen
chemically bonded to them.
A + O2 (g)  AXOy
The ratio of ‘A’ to oxygen will vary depending on
the charge of ‘A’.
Chemical Reactions
• 5 Types of Chemical Reactions
• Combustion Reactions
Mg (s) + O2 (g)  MgO (s)
Fe (s) + O2 (g)  Fe2O3 (s)
Technically, the rusting of iron is a
combustion reaction.
Chemical Reactions
• 5 Types of Chemical Reactions
• Combustion Reactions – These reactions
will always produce heat. If the molecule
reacting with the oxygen gas is a
hydrocarbon, then the products will
always be carbon carbon dioxide and
water.
CH4 (g) + 2O2 (g)  CO2 (g) + 2H2O (g)
Chemical Reactions
• 5 Types of Chemical Reactions
• Combustion Reactions – Predict the
products of the chemical reaction were
butane, (C4H6) burns.
C4H6 (g) + O2 (g) 
Chemical Reactions
• 5 Types of Chemical Reactions
• Single Replacement Reactions – Either a
metal replaces a metal in an ionic compound,
or a nonmetal replaces a nonmetal in an ionic
compound.
A + BC  AxCy + B
Al (s) + Cu(NO3)2 (aq)  Al(NO3)3 (aq) + Cu (s)
NaCl (aq) + F2 (g)  NaF (aq) + Cl2 (g)
Chemical Reactions
• 5 Types of Chemical Reactions
• Single Replacement Reactions – You need a
reference chart called an Activity Series to
determine if one element can replace the one
in the compound.
A + BC  AC + B
‘A’ has to be higher up on the Activity Series in
order to replace ‘B’.
Chemical Reactions
• 5 Types of Chemical Reactions
• Single Replacement Reactions
Chemical Reactions
• 5 Types of Chemical Reactions
• Single Replacement Reactions – Determine if
a chemical reaction will occur between silver
nitrate and calcium metal. If it does, predict
the products of the chemical reaction.
• Ca (s) + AgNO3 (aq) 
Chemical Reactions
• 5 Types of Chemical Reactions
• Single Replacement Reactions – What will
happen when solid lithium fluoride is
exposed to liquid chlorine gas?
LiF (s) + Cl2 (g) 
Chemical Reactions
• 5 Types of Chemical Reactions
• Double Replacement Reactions – The cations
of two ionic compounds switch anions.
AB + CD  AD + CD
• But one of the products has to be one of the
following;
• 1.) insoluble in water
• 2.) a gas
• 3.) a water molecule
Chemical Reactions
• 5 Types of Chemical Reactions
• Double Replacement Reactions
• AgNO3 (aq) + NaCl (aq)  NaNO3 (aq) + AgCl (s)
• HCl (aq) + NaOH (aq)  NaCl (aq) + H2O (l)
•
HNO3 (aq) + NaHCO3 (aq)  NaNO3 (aq) + H2O (l) + CO2 (g)
Chemical Reactions
• 5 Types of Chemical Reactions
• Double Replacement Reactions – A solubility
table must be used in order to determine
whether or not an ionic compound will be
soluble in water or not.
• Some general rules regarding solubility;
•
•
•
All nitrates are soluble.
All compounds that have ammonium as the cation is
soluble.
Salts containing lead, mercury, and silver are
generally not soluble but there are some exceptions.
Chemical Reactions
• 5 Types of Chemical Reactions
• Double Replacement Reactions – Will a
chemical reaction occur when aqueous
solutions of sodium chloride and lead (II)
nitrate are mixed? If so, what are the
products?
NaCl (aq) + Pb(NO3)2 (aq) 
Chemical Reactions
• 5 Types of Chemical Reactions
• Double Replacement Reactions – What will
happen when aqueous solutions of
potassium chloride and sodium hydroxide are
mixed?
KCl (aq) + NaOH (aq) 
Chemical Reactions
• 5 Types of Chemical Reactions
• All types of chemical reactions – Predict the products
of the following chemical reactions;
1.
CaCO3 (s) 
2. Li (s) + NaOH (aq) 
3. Mg (s) + N2 (g) 
4.
Na2SO4 (aq) + Ba(NO3)2 (aq) 
Chemical Reactions
• Net Ionic Equations
• A chemical equation which only the ions that
participate in the formation of the nonaqueous product are written.
General Equation: Na2SO4 (aq) + Ba(NO3)2 (aq  2NaNO3 (aq) + BaSO4 (s)
Ionic Equation: 2Na+1 (aq) + SO4-2 (aq) + Ba+2 (aq) + 2NO3-1 (aq)  2Na+1 (aq)
+ 2 NO3-1 (aq) + BaSO4 (s)
Net Ionic Equation: Ba+2 (aq) + SO4-2 (aq)  BaSO4 (s)
Chemical Reactions
• Net Ionic Equations
• Ions that do not participate in the net ionic equation are
called spectator ions.
General Equation: Na2SO4 (aq) + Ba(NO3)2 (aq  2NaNO3 (aq) + BaSO4 (s)
Ionic Equation: 2Na+1 (aq) + SO4-2 (aq) + Ba+2 (aq) + 2NO3-1 (aq)  2Na+1 (aq)
+ 2NO3-1 (aq) + BaSO4 (s)
Net Ionic Equation: Ba+2 (aq) + SO4-2 (aq)  BaSO4 (s)
Chemical Equations
• Writing Net Ionic Equations
• Write the net ionic for the chemical reaction
between sodium dichromate and mercury (II) nitrate.