General Chemistry I
Chapter 4 – Chemical Reactions and Chemical Quantities
Section 1 – Climate change & the combustion of fossil fuels
● Greenhouse gases → act as one-way filters, which allow visible light to
pass through & warm Earth’s surface, but prevents heat energy from
radiating back out into space
● Earth’s average temperature → the balance between incoming and
outgoing energy from the sun
● CO2 → A significant greenhouse gas which enhances the atmosphere’s
ability to hold heat (an increase in CO2 leads to global warming)
Section 2 – Writing & balancing chemical equations
● Chemical reaction → a process in which one or more substances are
converted into one or more different substances
○ Combustion reaction (Type of chemical reaction)
■ Substances combine with oxygen to form 1+
oxygen-containing compounds
■ This reaction emits heat, which is critical for supplying
society’s energy needs
● EX. Energy released from combustion of gasoline helps
a car engine to work
● Chemical equations → Represents a chemical reaction
, ● Balancing equations → change the
coefficients to ensure that the number of
each type of atom is equal on both left
and right sides of the equation
○ New atoms are not formed & old
atoms don't vanish during a
reaction (MATTER MUST BE
CONSERVED)
(g) = Gas (L) = Liquid (s) = Solid (aq) = aqueous (water solution)
Section 3 – Reaction stoichiometry
● Relationship between molecules to amounts in moles → the coefficients in
a chemical reaction specify relative amounts in moles of each of the
substances involved
The equation above represents = 16 moles of CO2 are produced for
every 2 moles of C8H18 burned
● Stoichiometry → Numerical relationship between chemical amounts in a
balanced chemical equation
Using the given equation, how many moles of CO2 form when 22.0 moles of
C8H18 burns?
➔ 2 moles C8H18 : 16 moles CO2
Using the given equation, what mass of CO2 is emitted upon the combustion of
4.0x10^15 grams C8H18?
grams C8H18 → mol C8H18 → mol CO2 → grams CO2
Molar mass C8H18 = 114.22 g/mol
Chapter 4 – Chemical Reactions and Chemical Quantities
Section 1 – Climate change & the combustion of fossil fuels
● Greenhouse gases → act as one-way filters, which allow visible light to
pass through & warm Earth’s surface, but prevents heat energy from
radiating back out into space
● Earth’s average temperature → the balance between incoming and
outgoing energy from the sun
● CO2 → A significant greenhouse gas which enhances the atmosphere’s
ability to hold heat (an increase in CO2 leads to global warming)
Section 2 – Writing & balancing chemical equations
● Chemical reaction → a process in which one or more substances are
converted into one or more different substances
○ Combustion reaction (Type of chemical reaction)
■ Substances combine with oxygen to form 1+
oxygen-containing compounds
■ This reaction emits heat, which is critical for supplying
society’s energy needs
● EX. Energy released from combustion of gasoline helps
a car engine to work
● Chemical equations → Represents a chemical reaction
, ● Balancing equations → change the
coefficients to ensure that the number of
each type of atom is equal on both left
and right sides of the equation
○ New atoms are not formed & old
atoms don't vanish during a
reaction (MATTER MUST BE
CONSERVED)
(g) = Gas (L) = Liquid (s) = Solid (aq) = aqueous (water solution)
Section 3 – Reaction stoichiometry
● Relationship between molecules to amounts in moles → the coefficients in
a chemical reaction specify relative amounts in moles of each of the
substances involved
The equation above represents = 16 moles of CO2 are produced for
every 2 moles of C8H18 burned
● Stoichiometry → Numerical relationship between chemical amounts in a
balanced chemical equation
Using the given equation, how many moles of CO2 form when 22.0 moles of
C8H18 burns?
➔ 2 moles C8H18 : 16 moles CO2
Using the given equation, what mass of CO2 is emitted upon the combustion of
4.0x10^15 grams C8H18?
grams C8H18 → mol C8H18 → mol CO2 → grams CO2
Molar mass C8H18 = 114.22 g/mol
