Chem 1048A
BHSc
Learning Goal 3B:
Stoichiometry
(Attendance at lectures is necessary to complete these notes)
Ms Brankin
Office 303
(011) 717-6729
, Stoichiometry
• Examines the quantities of substances
consumed and produced in chemical reactions.
• Stoichiometry is built on an understanding of :
i. Atomic masses
ii. Chemical formulas
iii. The Law of Conservation of Mass
(By weighing substances before and after chemical change, Lavoisier
(1743-1794) demonstrated the Law of Conservation of Mass which
states that: The total mass remains constant during a chemical
change i.e. a chemical reaction).
, Stoichiometry
• Atoms are neither created nor destroyed during any
chemical reaction.
• The changes that occur during any reaction merely
rearrange the atoms. The same collection of atoms
is present both before and after the reaction.
, Anatomy of a Chemical Equation
Concise representations of chemical reactions
STOICHIOMETRIC
“reacts with” SUBSCRIPT COEFFICIENT
CH4 (g) + 2O2 (g) ⎯⎯→ CO2 (g) + 2H2O (g)
reactants products
Text format
BHSc
Learning Goal 3B:
Stoichiometry
(Attendance at lectures is necessary to complete these notes)
Ms Brankin
Office 303
(011) 717-6729
, Stoichiometry
• Examines the quantities of substances
consumed and produced in chemical reactions.
• Stoichiometry is built on an understanding of :
i. Atomic masses
ii. Chemical formulas
iii. The Law of Conservation of Mass
(By weighing substances before and after chemical change, Lavoisier
(1743-1794) demonstrated the Law of Conservation of Mass which
states that: The total mass remains constant during a chemical
change i.e. a chemical reaction).
, Stoichiometry
• Atoms are neither created nor destroyed during any
chemical reaction.
• The changes that occur during any reaction merely
rearrange the atoms. The same collection of atoms
is present both before and after the reaction.
, Anatomy of a Chemical Equation
Concise representations of chemical reactions
STOICHIOMETRIC
“reacts with” SUBSCRIPT COEFFICIENT
CH4 (g) + 2O2 (g) ⎯⎯→ CO2 (g) + 2H2O (g)
reactants products
Text format
