Using R.I.C.E. Tables and stoichiometry with limiting reactants

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USING R.I.C.E. TABLES AND
STOICHIOMETRY WITH LIMITING
REACTANTS
RICE tables are a common tool of chemists (college
professors use then a lot!) to organize the
information for stoichiometry with a reaction and set
up mathematical equations when necessary to solve
for unknowns.
R = reaction (balanced)
I = initial conditions (before the reaction)
C = change (remove reactants, form products)
E = end conditions (after the reaction)
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
BEWARE: Moles goes into a RICE table and moles will
come out. To find volume will require a final step.
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
3O2 →
2CO2 +
2H2O
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
I=
C2H4 +
3O2 →
2CO2 +
2H2O
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
I=
10. g
3O2 →
2CO2 +
2H2O
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
3O2 →
I=
10. g
0.625 mol ?
2CO2 +
2H2O
0
0
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
I=
10. g
0.625 mol ?
C=
3O2 →
2CO2 +
2H2O
0
0
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
I=
C=
3O2 →
2CO2 +
2H2O
10. g
0.625 mol ?
0
0
-1x
+2x
+2x
-3x
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
I=
10. g
0.625 mol ?
C=
3O2 →
2CO2 +
2H2O
0
0
-1x
-3x
+2x
+2x
all the ethene will be burned, so x = 0.63 mol
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
I=
10. g
0.625 mol ?
C=
3O2 →
2CO2 +
2H2O
0
0
-1x
-3x
+2x
+2x
-0.625 mol -1.875 mol +1.25 mol +1.25 mol
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
I=
10. g
0.625 mol ?
C=
E=
3O2 →
2CO2 +
2H2O
0
0
-1x
-3x
+2x
+2x
-0.625 mol -1.875 mol +1.25 mol +1.25 mol
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
R=
C2H4 +
3O2 →
I=
10. g
0.625 mol ?
2CO2 +
2H2O
0
0
C=
-1x
-3x
+2x
+2x
-0.625 mol -1.875 mol +1.25 mol +1.25 mol
E=
0
?-1.875 mol 1.25 mol
1.25 mol
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
How many moles of CO2 was formed?
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
How many moles of CO2 was formed?
1.3 mol
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
How many moles of CO2 was formed?
What volume of CO2 was formed?
1.3 mol
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
How many moles of CO2 was formed?
What volume of CO2 was formed?
1.25 mol x 22.4 L/mol = 28 L
1.3 mol
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
How many moles of CO2 was formed?
What volume of CO2 was formed?
1.25 mol x 22.4 L/mol = 28 L
1.3 mol
What other information do we already know?
Example 1: 10. grams of ethene is combusted. What
volume of carbon dioxide will be formed?
How many moles of CO2 was formed?
What volume of CO2 was formed?
1.25 mol x 22.4 L/mol = 28 L
1.3 mol
What other information do we already know?
•Moles of O2 consumed
•Moles of H2O produced
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
R=
C2H4 +
3O2 →
2CO2 +
2H2O
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
R=
C2H4 +
3O2 →
I=
10. g
50. g
0.625 mol 1.56 mol
2CO2 +
2H2O
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
R=
C2H4 +
3O2 →
2CO2 +
2H2O
I=
10. g
50. g
0.625 mol 1.56 mol
C=
-1x
-3x
+2x
+2x
WHICH X TO USE? SMALLEST X!
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
R=
C2H4 +
3O2 →
2CO2 +
2H2O
I=
10. g
50. g
0.625 mol 1.56 mol
C=
-1x
-3x
+2x
+2x
WHICH X TO USE? SMALLEST X!
If 0.625 = 1 x, then x = 0.625
If 1.56 = 3 x, then x = 0.521 ← SMALLEST
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
R=
C2H4 +
3O2 →
2CO2 +
2H2O
I=
10. g
50. g
0.625 mol 1.56 mol
C=
-1x
-3x
+2x
+2x
-0.521 mol -1.56 mol +1.04 mol 1.04 mol
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
R=
C2H4 +
3O2 →
2CO2 +
I=
10. g
50. g
0.625 mol 1.56 mol
C=
-1x
-3x
+2x
+2x
-0.521 mol -1.56 mol +1.04 mol 1.04 mol
E = 0.625 mol – 0.521 mol 1.56 mol – 1.56 mol 1.04 mol
0.104 mol 0
1.04 mol
2H2O
1.04 mol
1.04 mol
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
What volume of CO2 is actually produced?
1.04 mols x 22.4 L/mol = 23 L
Example 2: 10. grams of ethene is combusted with 50.
grams of O2. What volume of carbon dioxide can be
formed?
What volume of CO2 is actually produced?
1.04 mols x 22.4 L/mol = 23 L
What else do we know?
•Moles of ethene left over
•Moles of water actually produced
Why use a RICE table for limiting reactant problems?
How many RR tracks would it have taken?
Why use a RICE table for limiting reactant problems?
How many RR tracks would it have taken?
2 to figure out which one is limiting
Why use a RICE table for limiting reactant problems?
How many RR tracks would it have taken?
2 to figure out which one is limiting
1 more to find amount of excess
Why use a RICE table for limiting reactant problems?
How many RR tracks would it have taken?
2 to figure out which one is limiting
1 more to find amount of excess
1 more for each of the additional products
Why use a RICE table for limiting reactant problems?
How many RR tracks would it have taken?
2 to figure out which one is limiting
1 more to find amount of excess
1 more for each of the additional products
It is your choice. We did 1 RICE table vs 4 RR Tracks.
RICE tables will be necessary later. For now, it is
optional.

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