INORGANIC & ORGANIC CHEM LEC
Ms. Jazheerine Portugal | Chemical Reactions and Chemical Equations
CHEMICAL REACTIONS
A process in which a substance (or substances)
is changed into one or more new substances
BALANCING CHEMICAL EQUATION
Two moles hydrogen molecules can combine
with one mole oxygen molecule to form two
moles water molecules
We can balance the equation by placing
the appropriate coefficient in front of the
compounds.
CHEMICAL EQUATIONS
Uses chemical symbols to show what happens
during a chemical reaction.
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Molecular hydrogen reacts with molecular
oxygen to yield water.
What if?
It is also correct however; it is common practice
to use the simplest possible set of whole-number
coefficients to balance the equation.
IS THE EQUATION BELOW COMPLETE?
Write a balanced equation for the formation of
According to the “Law of Conservation of Mass”, the products
must have the same amount as the reactant.
ACS - MED 237 | 1
BALANCING CHEMICAL EQUATION
TYPES OF CHEMICAL REACTIONS
To provide additional information, chemists
indicate physical states of reactants and
products by using the letters g, l and s to denote
gas, liquid and solid.
INTERPRETATION OF CHEMICAL
EQUATION
Chemical equations are used to denote the type
of chemical reaction involved and the quantity of
reactants and products present (Stoichiometry).
Chemical equations are used to denote the type
of chemical reaction involved and the quantity
of reactants and products present
(Stoichiometry).
Chemical equations are used to denote the type
of chemical reaction involved and the quantity
of
reactants
and
products
present
(Stoichiometry).
Chemical equations are used to denote the type
of chemical reaction involved and the quantity of
reactants and products present (Stoichiometry).
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STOICHIOMETRY
To interpret a reaction quantitatively, we need to
apply our knowledge of molar masses and the
mole concept.
Stoichiometry is the quantitative study of
reactants and products in a chemical reaction.
The stoichiometric coefficients in a chemical
equation can be interpreted as the number of
moles of each substance.
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Or
EXAMPLE: 16.0 g of H2 react completely with
N2 to form NH3. How many grams of NH3 will be
formed?
CHALLENGE : The food we eat is degraded or
broken down in our bodies to provide energy for
growth and function. A general overall equation
for this very complex process represents the
degradation of Glucose (C6H12O6) to carbon
dioxide (CO2) and water (H2O) :
(C6H12O6) + 6O2 —> 6CO2 + 6H2O
If 856 g of (C6H12O6) is consumed by a person
over a certain food, what is the mass of CO2
produced?
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CHALLENGE: All Alkali metals react
with water to produce hydrogen gas and
the
corresponding
alkali
metal
hydroxide. A typical reaction is between
lithium and water.
2Li (s) + 2H2O (l) —> 2 LiOG (aq) +
H2 (g)
How many grams of Li are needed to produce
9.89 of H2?
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