The document provides information on how to write and interpret chemical equations. It defines reactants and products, explains the symbols used in equations, and describes the five main types of chemical reactions: synthesis, decomposition, single replacement, double replacement, and combustion.

4. 1. Reactants = the substances you
start with
2. Products = the substances you
end up with
∞
∞

5. - Page
321
Products
Reactants

7. •The way atoms are
joined is changed
Atoms aren’t created
or destroyed.

10. ∞the arrow (→)
separates the reactants
from the products (arrow
points to products)
∞Read as: “reacts to
form” or yields
∞ The plus sign = “and”

11. ∞(s) after the formula = solid:
Fe(s)
∞ (g) after the formula = gas:
CO2(g)
∞ (l) after the formula = liquid:
H2O(l)
∞(aq) after the formula =
dissolved in water, an aqueous
solution: NaCl(aq) is a salt water
solution.

12. ∞ indicates a reversible
reaction.
∞ shows that
heat is supplied to the reaction.
∞ , or is used to
indicate a catalyst used supplied, in
this case, platinum.
∞ , indicates
a pressure other than STP.

13. ∞used after a product
indicates a gas has been
produced: H2↑
∞ used after a product
indicates a solid has been
produced: PbI2↓

14. Summary of Symbols

15. What is a Catalyst?
• A substance that speeds up a
reaction without being changed
by the reaction.
• Enzymes are biological or
protein catalysts.

17. .
Exothermic - reactions that release
energy to their surroundings (usually in
the form of heat)
Endothermic - reactions that need to
absorb heat from their surroundings to
proceed.

18. • Spontaneous Reactions - Reactions
that proceed immediately when two
substances are mixed together. Not all
reactions proceed spontaneously.
• Activation Energy – the amount of
energy that is required to start a
chemical reaction.
• Once activation energy is reached the
reaction continues until you run out of
material to react.

21. • Uses formulas and symbols to
describe a reaction
• doesn’t indicate how many.
• All chemical equations are
sentences that describe
reactions.

23. ∞There are 8 elements that
never want to be alone.
∞They form diatomic molecules.
∞H2 , N2 , O2 , F2 , Cl2 , Br2 , I2 ,
and At2
∞The –ogens and the –ines
∞1 + 7 pattern on the periodic
table

30. Solid iron reacts with oxygen
gas to form solid iron oxide
(rust).

31. A silver spoon tarnishes. The solid silver
reacts with sulfur in the air to make solid
silver sulfide, the black material we call
tarnish.

34. ∞Also called combination
reactions.
∞2 elements, or compounds
combine to make one compound.
∞A + B AB
∞Na (s) + Cl2 (g) NaCl (s)
∞Ca (s) +O2 (g) CaO (s)

35. ∞SO3(s) + H2O(l) H2SO4 (s)
∞We can predict the
products if they are two
elements.
∞Mg (s) + N2 (g) Mg3N2 (s)

36. ∞ Additional Important Notes:
a) Some nonmetal oxides react
with water to produce an acid:
SO2 + H2O  H2SO3
(This is what happens to make
“acid rain”)
b) Some metallic oxides react
with water to produce a base:
CaO + H2O  Ca(OH)2

39. ∞decompose = fall apart
∞one compound (reactant) falls apart
into two or more elements or
compounds.
∞Usually requires energy
∞AB A + B
electricity
∞NaCl Na + Cl2
∞CaCO3 CaO + CO2

40. ∞Can predict the products if it
is a binary compound (made up
of only two elements)
∞Falls apart into its elements
∞H2O electricity H2 (g) + O2 (g)
∞HgO Hg (s) + O2 (g)

41. ∞If the compound has more
than two elements you must
be given one of the products
∞The other product will be
from the missing pieces
∞NiCO3 (aq) CO2 (g)+ Ni (s)
∞H2CO3(aq) H2 (g)+ CO2 (g)

43. ∞Also referred to as single
displacement
∞ One element replaces another
∞Reactants must be an element
and a compound.
∞Products will be a different
element and a different
compound.

44. ∞ Na + KCl K + NaCl
(Cations switched)
∞ F2 + LiCl LiF + Cl2
(Anions switched)

45. ∞A+BC AC+B
∞2Na + SrCl2 Sr +
2NaCl
∞F2 + LiCl LiF + Cl2

46. ∞We can tell a
reaction will happen
∞Some are more active
than other
∞More active replaces
less active

47. The “Activity Series” of Metals
Higher Lithium
activity Potassium 1) Metals can replace other
Calcium
Sodium
metals, provided they are
Magnesium above the metal they are
Aluminum
Zinc trying to replace
Chromium (for example, zinc will replace lead)
Iron
Nickel 2) Metals above hydrogen can
Lead
Hydrogen replace hydrogen in acids.
Bismuth
Copper
Mercury 3) Metals from sodium upward
Silver
Lower
Platinum
can replace hydrogen in
activity
Gold water.

48. The “Activity Series” of Halogens
Higher Activity
Halogens can replace other
Fluorine halogens in compounds,
Chlorine
Bromine
provided they are above the
Iodine halogen they are trying to
Lower Activity replace.
2NaCl(s) + F2(g)  ???
2NaF(s) + Cl2(g)
MgCl2(s) + Br2(g)  ???
No Reaction!

50. ∞Two things replace each
other.
∞Reactants must be two
ionic compounds or acids.
∞Usually in aqueous solution
∞ AB+CD AD+CB

51. ∞ZnS + 2HCl
ZnCl + H2S
AgNO3 + NaCl
∞
AgCl + NaNO3

52. ∞ NaOH + FeCl3
-The positive ions change
place.
∞NaOH + FeCl3 Fe+3 OH-
+ Na+1 Cl-1
= NaOH + FeCl3 Fe(OH)3
+ NaCl

53. ∞Have certain “driving forces”, or
reasons
-Will only happen if one of the
products:
a) doesn’t dissolve in water and
forms a solid (a “precipitate”), or
b) is a gas that bubbles out, or
c) is a molecular compound (which
will usually be water).

55. ∞Combustion means “add oxygen”
∞Normally, a compound composed
of only C, H, (and maybe O) is
reacted with oxygen – usually
called “burning”
∞If the combustion is complete,
the products will be CO2 and H2O.
∞If the combustion is incomplete,
the products will be CO (or
possibly just C) and H2O.

56. ∞A reaction in which a compound (often
carbon) reacts with oxygen
∞ CH4 + O2 CO2 + H2O
∞ C3H8 + O2 CO2 + H2O
∞ C6H12O6 + O2 CO2 + H2O

57. The charcoal used
in a grill is
basically carbon.
The carbon reacts
with oxygen to
yield carbon
dioxide. The
chemical equation
for this reaction
is C + O2  CO2

59. ∞An acid and a base react to form
a salt and water.
∞Always in aqueous solution
∞Acid (H+) + Base (OH-) →
Salt + H2O
NaOH + HCl → NaCl + H2O
NH4OH + H2SO4 → (NH4)2SO4 + H2O

63. ∞ H2 + O2 Synthesis
∞H2O Decomposition
∞ AgNO3 + NaCl Double replacement
∞ Zn + H2SO4 Single replacement
∞ HgO Decomposition
∞ KBr +Cl2 Single replacement
∞ Mg(OH)2 + H2SO3 Double replacement

64. ∞ HNO3 + KOH Acid/Base
∞ CaPO4 Decomposition
∞ AgBr + Cl2 Single replacement
∞ Zn + O2 Synthesis
∞ HgO + Pb Single replacement
∞ HBr + NH4OH Acid/Base
∞ Cu(OH)2 + KClO3 Double replacement

66. An equation:
∞Describes a reaction
∞Must be balanced because to follow
Law of Conservation of Energy
∞Can only be balanced by changing the
coefficients.
∞Has special symbols to indicate state,
and if catalyst or energy is required.
∞Can describe 5 different types of
reactions.