Limiting
reactant is the reactant that limits the progress of the reaction by being
lesser in quantity then required. The reaction therefore stops after the
limiting reactant is used up.
Example:
Calculate
the mass and volume of CO2 and H2O produced when 32g of
CH4 is combusted with 32g of O2.
Equation:
Equation
tells that:
16g
of CH4 needs 64g of O2 to produce 44g of CO2
and 36g of H2O
Since,
the quantities of both the reactants is given, first let us find the limiting
reactant.
Therefore:
In
this reaction only 8g of CH4 burns as after that all the O2
is used up and the reaction cannot go further.
Equation
tells that:
16g
of CH4 needs 64g of O2 to produce 44g of CO2
and 36g of H2O
According
to the given situation:
8g
of CH4 needs 32g of O2 to produce r g of CO2
and s g of H2O
i.
Calculating the mass in
grams of CO2 released after 8g of combustion of CH4
with 32g of O2:
22g of CO2 is released after 8g of combustion of
CH4 with 32g of O2
ii.
Calculating the volume of
CO2 released:
iii.
Calculating the mass in
grams of H2O released after 8g of combustion of CH4
with 32g of O2:
18g of H2O is released after 8g of combustion of
CH4 with 32g of O2
iv.
Calculating the volume of H2O
released:
Ideally,
after the end of this reaction, Oxygen will be entirely used up while 24g of
Methane will remain unreacted.
