Unit 10:
Energy in Chemical
Reactions
Cypress Creek High School
Chemistry 1K
Chapter 10
Solubility Rules
• We will use a solubility chart to determine if chemicals
will be:
– Soluble in water and considered aqueous (aq) or…
– Insoluble in water and be considered precipitates/solids (s)
• The solubility chart lists ions (single or multiple
elements that have a collective charge) and their
solubilities. These ions will be written with a +/ – and a
number written as a superscript.
– Ion Examples…
•
•
•
•
Ca2+ is the element calcium’s ion
F– is the element fluorine’s ion
SO42- is a polyatomic ion made up of sulfur & oxygen named sulfate
NH4+ is a polyatomic ion made up of nitrogen & hydrogen named ammonium
Solubility Rules
• The chart also mentions alkali metal cations,
which include the following elements in the
first column of the periodic table:
– Li+
– Na+
– K+
– Rb+
– Cs+
– Fr+
Any compound not listed in these general rules is considered insoluble.
Solubility Rules Chart
Any compound
that contains
these ions is
always soluble
Any compound
that contains
these ions is
always soluble
except with
the ions listed
Any compound
that contains
these ions is
never soluble
except with
the ions listed
Solubility Practice
• Practice using the solubility rules for the
following compounds:
– Ca(NO3)2 (aq) Soluble: contains NO3– AgCl (s) Insoluble: Cl- is soluble, unless paired
with Ag+, Pb2+, or Hg22+
– Ni(OH)2 (s) Insoluble: OH- is insoluble, unless
paired with NH4+, the alkali metal
cations, Ca2+, Sr2+, or Ba2+
Combustion Reaction
• Whenever hydrocarbons combine
rapidly with oxygen (usually by fire),
the reaction is called a combustion
reaction.
– The products will be water
and carbon dioxide.
– Burning methane (CH4) yields
water and carbon dioxide
• This reaction contributes to our
greenhouse gases and global
warming.
Identifying Chemical Reactions
• Identify each of the following chemical equations as synthesis,
decomposition, single-displacement, double-displacement, or
combustion reaction.
A)
B)
C)
Predicting Chemical Reactions
Steps
1. Determine what type of reaction is being presented
2. Write the correct formulas for the product(s)
3. Balance the equation
Example: CaCl2 + Al(OH)3  ?
1. Double-displacement reaction
2. __CaCl2 + __Al(OH)3  __Ca(OH)2 + __AlCl3
3. 3CaCl2 + 2Al(OH)3  3Ca(OH)2 + 2AlCl3
Predicting Chemical Reactions
Practice
• Predict the chemical reaction: NaCl (aq) + Pb(NO3)2 (aq)  ?
2NaCl (aq) + Pb(NO3)2 (aq)  PbCl2 (s) + 2NaNO3 (aq)
• Predict the chemical reaction: Mg (s) + CuSO4 (aq)  ?
Mg (s) + CuSO4 (aq)  MgSO4 (aq) + Cu (s)