LIMITING REAGENTS
This function works with all the other functions for one way reactions.
If you have two or more reactants that are restricted in their quantity
then you may use
the REAGENT LIMITS
sheet for entering quantities instead of the BASIC QUANTITIES sheet.
1.
Given the equation Fe+S=>FeS, if we combine 7.62 grams of Fe and
8.67 grams of S, how much FeS will be produced?
Solution:
-We
enter the equation and SUBMIT it.
-Then we hit the REAGENT LIMITS button.
-We
enter 7.62 in the grams max column of Fe and 8.67 in the grams max column of
S.
-Then we hit STEPPER (CALCULATE) and note that 7.62 is highlighted.
-This means Fe is
the limiting reagent.
-We hit the BASIC QUANTITIES button and read the grams
of FeS ( 12.0 ).
2. If we burn
2.64 liters of acetylene gas with 1.23 liters of oxygen at STP, how many
grams of H2O will be produced? ( unbalanced formula: C2H2 + O2 => CO2 + H2O
)
Solution:
-We enter the unbalanced equation and SUBMIT it.
-We
hit the GASES/VAPORS button and enter 0 in the degC column for C2H2 and 0 in
the degC column for O2.
-We enter 1 in the atm column for C2H2 and 1 in the
atm column for O2.
-Note these are not partial pressure gases since they are
not being measured in the same container.
-They should be indicated as
ideal.
-Now we hit the REAGENT LIMITS button and enter 2.64 in the Liters
Max column for C2H2 and 1.23 in the Liters Max column of O2.
-Finally, we hit
the STEPPER (CALCULATE) button.
-Note that 1.23 becomes highlighted indicating that O2 is
the limiting reagent.
-For the answer, hit the BASIC QUANTITIES button and
read the grams column of H2O ( 0.3957 ).
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