Slide 1 / 109 Stoichiometric Calculations Slide 2 / 109 Table of Contents · Stoichiometry Calculations with Moles Click on the topic to go to that section · Stoichiometry Calculations with Particles and Volume · Stoichiometry Calculations with Mass · Mixed Stoichiometry Problems · Limiting Reactants · Theoretical, Actual and Percent Yield · Calculating Excess Reactants Slide 3 / 109
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Slide 1 / 109
StoichiometricCalculations
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Table of Contents
· Stoichiometry Calculations with Moles
Click on the topic to go to that section
· Stoichiometry Calculations with Particles and Volume· Stoichiometry Calculations with Mass· Mixed Stoichiometry Problems· Limiting Reactants· Theoretical, Actual and Percent Yield· Calculating Excess Reactants
The number of particles (atoms, molecules, formula units) is directly to proportional to the number of moles. Therefore...
2 H2 + O2 --> 2 H2 O
can be read as:
2 molecules of H2 plus 1 molecule of O2 yields 2 molecules of H2 O.
Note...while moles can be expressed as non-whole numbers, particles must be whole numbers. One cannot have 6.1 atoms, molecules, or formula units!
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16 What is the largest number of of Li3 N formula units that could result from reacting 6 N2 molecules?
6 Li (s) + N2 (g) --# 2 Li3 N (s)
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16 What is the largest number of of Li3 N formula units that could result from reacting 6 N2 molecules?
6 Li (s) + N2 (g) --# 2 Li3 N (s)
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1 molecule N2
6 N2 molecules x 2 Li3N formula units = 12 Formula units Li3N
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17 How many N2 molecules would be required to create 4 Li3 N formula units?
6 Li (s) + N2 (g) --# 2 Li3 N (s)
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17 How many N2 molecules would be required to create 4 Li3 N formula units?
6 Li (s) + N2 (g) --# 2 Li3 N (s)
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2
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18 How many Li atoms would be required to completely react with 3 N2 molecules?
6 Li (s) + N2 (g) --# 2 Li3 N (s)
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18 How many Li atoms would be required to completely react with 3 N2 molecules?
6 Li (s) + N2 (g) --# 2 Li3 N (s)
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18
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Stoichiometry Calculations with Volumes At a given temperature and pressure, the space a sample of a gas takes up (it's volume) is proportional to the number of moles of gas molecules present. Therefore...
2 H2 (g) + O2 (g) --> 2 H2 O(g)
can be read as:
2 volumes of H2 plus 1 volume of O2 yields 2 volumes of H2 O.
Note: The volume of a material is only proportional to the number of moles when the substance is in the gas phase!
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19The equation below shows the decomposition of lead nitrate. How many liters of oxygen are produced when 12L of NO2 are formed? (STP)
2Pb(NO3 )2 (s) --> 2PbO (s) +4NO2 (g) + O2 (g)
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19The equation below shows the decomposition of lead nitrate. How many liters of oxygen are produced when 12L of NO2 are formed? (STP)
2Pb(NO3 )2 (s) --> 2PbO (s) +4NO2 (g) + O2 (g)
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12 L NO2 x 1 L O2 = 3 L of O2
4 L NO2
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20 What volume of methane is needed to completely react with 500 mL of O2 at STP? (Balance the equation first!!!)
__ CH4 + ___ O2 --# ___ CO2 + ___ H2 O
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20 What volume of methane is needed to completely react with 500 mL of O2 at STP? (Balance the equation first!!!)
__ CH4 + ___ O2 --# ___ CO2 + ___ H2 O
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250
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21 How many liters of H2 O (g) will be created from reacting 8.0 L of H2 (g) with a sufficient amount of O2 (g)?
2 H2 (g) + O2 (g) --# 2 H2 O (g)
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21 How many liters of H2 O (g) will be created from reacting 8.0 L of H2 (g) with a sufficient amount of O2 (g)?
2 H2 (g) + O2 (g) --# 2 H2 O (g)
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8
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22 How many liters of NO2 (g) will be created from reacting 36 L of O2 (g) with a sufficient amount of NH3 (g)?
4 NH3 (g) + 7 O2 (g) --# 4 NO2 (g) + 6 H2 O (g)
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22 How many liters of NO2 (g) will be created from reacting 36 L of O2 (g) with a sufficient amount of NH3 (g)?
4 NH3 (g) + 7 O2 (g) --# 4 NO2 (g) + 6 H2 O (g)
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20.6
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Stoichiometry with Particles and Volumes
It's common to be asked to report a value in a unit other than the one given.
For example:
Given the following reaction, how many L of nitrogen gas would be needed to produce 3 moles of ammonia?
N2(g) + 3H2(g) --> 2NH3
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Given the following reaction, how many liters of nitrogen gas would be needed @STP to produce 3 moles of ammonia?
N2(g) + 3H2(g) --> 2NH3
mol NH3 --> mol N2 --> L N2
3 mol NH3 x 1 mol N2 x 22.4 L = 33.6 L N2
2 mol NH3 1 mol
Stoichiometry with Particles and Volumes
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Example 2: How many moles of Cl2 gas would be needed to produce 3 x 1024 formula units of NaCl given the following reaction.
2Na(s) + Cl2(g) --> 2NaCl(s)
formula units NaCl --> molecules Cl2 --> mol Cl2
3 x 1024 formula units NaCl x 1 molecule Cl2 x 1 mol Cl2
2 for. units NaCl 6.02 x 1023 molecules
= 2.5 mol Cl2
Stoichiometry with Particles and Volumes
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23 How many sodium atoms would be needed to react with 33.6 L of chlorine gas at STP?
2Na(s) + Cl2(g) --> 2NaCl
Note: Sodium is a solid and therefore cannot be expressed in L, so first convert the chlorine gas to moles.
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23 How many sodium atoms would be needed to react with 33.6 L of chlorine gas at STP?
2Na(s) + Cl2(g) --> 2NaCl
Note: Sodium is a solid and therefore cannot be expressed in L, so first convert the chlorine gas to moles.
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Strategize!! L Cl2 --> n Cl2 --> n Na --> atoms Na
33.6 L Cl2 x 1 mol Cl2 x 2 mol Na x 6.02 x 1023 atoms Na
22.4 L 1 mol Cl2 mol Na
= 1.8 x 1024 atoms Na
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24 How many liters of oxygen gas would need to be combusted with excess hydrocarbon to produce 5.5 moles of water @STP?
Example: How many grams of hydrogen gas would need to react with 3.4 moles of oxygen gas?
2H2(g) + O2(g) --> 2H2O(g)
mol O2 --> mol H2 --> g H2
3.4 mol O2 x 2 mol H2 x 2 g H2 = 13.6 g H2
1 mol O2 1 mol H2
Mass Relationships in Stoichiometry
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Starting with the mass of Substance A you can use the ratio of the coefficients of A and B to calculate the mass of Substance B formed (if a product) or used (if a reactant).
aA bB
Mass-Mass Calculations
Grams of substance A Grams of
substance B
Moles of substance A
Moles of substance B
Use molar mass of A Use molar
mass of B
Use coefficients of A and B
from balanced equation
Given Find
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Mass-Mass Calculations
Example: Calculate the mass of ammonia, NH3 , produced by the reaction of 5.4 g hydrogen gas with an excess of nitrogen.
N2 + 3H2 ---> 2NH3
Strategize!! g H2 --> mol H2 --> mol NH3 --> g NH3
5.4 g H2 x 1 mol H2 x 2 mol NH3 x 17 g NH3
2 g H2 3 mol H2 1 mol NH3
= 30.6 g NH3
Move for answer
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28 What is the mass of sodium produced when 40 grams of sodium azide decompose?
2 NaN3 (s) --> 2 Na (s) + 3 N2 (g)
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28 What is the mass of sodium produced when 40 grams of sodium azide decompose?
2 NaN3 (s) --> 2 Na (s) + 3 N2 (g)
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14.1
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29 How many grams of Al2 O3 will be created from reacting 36 g of Al with a sufficient amount of O2 ?
4 Al (s) + 3 O2 (g) --> 2 Al2O3 (s)
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29 How many grams of Al2 O3 will be created from reacting 36 g of Al with a sufficient amount of O2 ?
4 Al (s) + 3 O2 (g) --> 2 Al2O3 (s)
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68
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30 How many grams of Mg must react in order to to create 84 g of MgO?
2 Mg (s) + O2 (g) --> 2 MgO (s)
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30 How many grams of Mg must react in order to to create 84 g of MgO?
Generally speaking, it is easiest to convert to moles first.
mol A mol B
L of A
g of A
particles of A
g of B
L of B
particles of B
Mixed Stoichiometry Problems
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Mixed Stoichiometry Calculations
Every type of stoichiometry calculation may be solved by following this map.
(1) From left to right, we convert any "Given" substance to moles. (2) Next, using the mole ratio created with coefficients, one can calculate the moles of the "Wanted" quantity.
(3) Finally, if necessary, moles can be converted to either particles, mass or volume.
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Mixed Stoichiometry Calculations
(1)
(2)
(3)
representative particles of G
1 mol G 6.02 x 1023
mass of G
1 mol G mass G
1 mol G 22.4 L G
volume of G at STP
mol G b mol W a mol G
mol W
representative particles of W
6.02 x 1023
1 mol W
mass W 1 mol W
mass of W
22.4 L W 1 mol W
Volume of W at STP
=
=
=
=
=
=
x
x
x
x
x
x=x
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31 How many L of water vapor can be produced from the combustion of 1 gram of glucose @STP?
C6H12O6(s) + 6 O2(g) --> 6 CO2(g) + 6 H2O(g)
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31 How many L of water vapor can be produced from the combustion of 1 gram of glucose @STP?
C6H12O6(s) + 6 O2(g) --> 6 CO2(g) + 6 H2O(g)
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0.75
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32 What mass of CaO would be required to completely react with 42 grams of H2O at STP?
CaO (s) + H2O (l) --> Ca(OH)2 (s)
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32 What mass of CaO would be required to completely react with 42 grams of H2O at STP?
CaO (s) + H2O (l) --> Ca(OH)2 (s)
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131
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33 How many grams of iron can be extracted from 500 kg of iron ore? (Make sure you balance the equation first and remember to convert your kg --> g)
Fe2O3 (s) + C (s) --> Fe (s) + CO2 (g)
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33 How many grams of iron can be extracted from 500 kg of iron ore? (Make sure you balance the equation first and remember to convert your kg --> g)
Fe2O3 (s) + C (s) --> Fe (s) + CO2 (g)
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350,000
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34 How many grams of ammonia can be produced by reacting 10 moles of nitrogen gas with excess hydrogen gas @STP?
N2(g) + 3H2(g) --> 2NH3(g)
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34 How many grams of ammonia can be produced by reacting 10 moles of nitrogen gas with excess hydrogen gas @STP?
N2(g) + 3H2(g) --> 2NH3(g)
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3.40
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35 How many L of O2 gas @STP are required to produce 90 grams of aluminum oxide?
4Al(s) + 3O2(g) --> 2Al2O3(s)
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35 How many L of O2 gas @STP are required to produce 90 grams of aluminum oxide?
4Al(s) + 3O2(g) --> 2Al2O3(s)
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29.6
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36 How many grams of chlorine gas are needed to react with 1 mole of Sb @STP?
2 Sb + 3 Cl2 --> 2 SbCl3
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36 How many grams of chlorine gas are needed to react with 1 mole of Sb @STP?
2 Sb + 3 Cl2 --> 2 SbCl3
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106.5
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37 How many moles of aluminum oxide are produced when 3.580 kg of manganese dioxide are consumed?
3MnO2 (s) + 4 Al(s) --> 2 Al2 O3 (s) + 3Mn(s)
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37 How many moles of aluminum oxide are produced when 3.580 kg of manganese dioxide are consumed?
3MnO2 (s) + 4 Al(s) --> 2 Al2 O3 (s) + 3Mn(s)
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27.4
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38 How many moles of manganese dioxide will be needed to react with 6 x 1025 atoms of Al?
3MnO2 (s) + 4 Al(s) --> 2 Al2 O3 (s) + 3Mn(s)
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38 How many moles of manganese dioxide will be needed to react with 6 x 1025 atoms of Al?
3MnO2 (s) + 4 Al(s) --> 2 Al2 O3 (s) + 3Mn(s)
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75
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39 If 4.37 moles of Al are consumed, how many formula units of aluminum oxide would be produced?
3MnO2 (s) + 4 Al(s) --> 2 Al2 O3 (s) + 3Mn(s)
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39 If 4.37 moles of Al are consumed, how many formula units of aluminum oxide would be produced?
3MnO2 (s) + 4 Al(s) --> 2 Al2 O3 (s) + 3Mn(s)
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1.3 x 1024
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Here
2 C57 H110 O6 (s) + 163 O2 (g) --> 114 CO2 (g) + 110 H2 O(l)
At STP, what volume of carbon dioxide is produced when 50 grams of tristearin is burned by the camel?
Real World Application
tristearin
The compound tristearin (C57H110O6) is a type of fat which camels store in their hump and is used to make chocolate. (yes, really)
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Return toTable ofContents
Limiting Reactants
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Concept of the Limiting ReactantIn a chemical reaction, do all of the reactants turn into products?
What happens when one of the reactants gets used up?
If the following reaction starts with 10 moles of H2 and 20 moles of Cl2, which reactant will run out of first?
Concept of the Limiting ReactantThe 10 moles of H2 are used to produce 20 moles of HCl. When the H2 is all used up, no more HCl can be produced.
Were all the moles of Cl2 used up?
How many are left over?
H2(g) + Cl2(g) --> 2HCl(g)
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Concept of the Limiting ReactantNo more HCl can be produced once the H2 runs out, therefore, H2 is the Limiting Reactant (limits the amount of product).
Since the reaction started with more Cl2 than H2, not all of the Cl2 is used up in the reaction.
Cl2 is the Excess Reactant (there's an excess amount).
H2(g) + Cl2(g) --> 2HCl(g)
Left-over Cl2 not used in the reaction to make HCL
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Limiting Reactants
The limiting reactant, or limiting reagent, is the reactant present in the smallest stoichiometric amount.
This is not necessarily the one with the smallest mass.
The limiting reactant is the reactant you’ll run out of first, and it is the one that determines the maximum amount of product that can be made.
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Limiting reagent problems are worded differently because the quantities of both reactants are given.
10 moles of H2 and 20 moles of Cl2 react to produce HCl. Which quantity is the limiting reagent?
It is your job to figure out which reactant is limiting because that will determine the maximum amount of product you can get, also called the maximum yield.
There are a variety of methods to determine which reactant is the limiting one.
Limiting Reactants
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Steps to Determine the Limiting Reactant
A series of steps can be used to determine the limiting reactant in any reaction:
Step 1: Convert the given quantities into moles. These are your initial amounts of each reactant.
Step 2: Divide each by its stoichiometrical coefficient from the balanced chemical equation. This factors in how much is needed in the reaction.
Step 3: Whichever reagent has the smallest quantity must be the limiting reactant!
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Determining the Limiting Reactant
Example: When 10 grams of hydrogen react with 3.4 moles of nitrogen gas to make ammonia, which substance would be the limiting reactant?
N2(g) + 3H2(g) --> 2NH3(g)
Step 1: Convert all values to moles.
10 g H2 x 1 mol H2 = 5 mol H2
2 g H2
Initial Amounts = 5 mol H2, 3.4 mol N2
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Step 2: Find the stoichiometrical equivalents of each reactant
Initial: 3.4 mol 5 mol
Divide by coefficient: 3.4/1 5/3
Available Amounts: 3.4 mol 1.66 mol
Step 3: Since there is less hydrogen gas, it will be the limiting reactant!
N2(g) + 3H2(g) --> 2NH3(g)
Determining the Limiting Reactant
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Limiting Reactants
Example: If 10 moles of hydrogen gas react with 7 moles of oxygen gas @STP to make water, which is the limiting reactant?
2H2(g) + O2(g) --> 2H2O(g)
Step 1:
Both amounts are already in moles!
Step 2:
10 mol H2/2 = 5 mol H2 available
7 mol O2/1 = 7 mol O2 available
Step 3:
H2 gas is the limiting reactant. O2 gas will be left over and is the excess reactant.
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Limiting ReactantsExample: Given that 2H2O(g) + O2(g) -->2H2O2(l)
If 36 grams of water react with 44.8 L of oxygen gas @STP, which substance is the limiting reactant?
Step 1:
36 g H2O x 1 mol = 2 mol H2O 44.8 L O2 x 1 mol = 2 mol O2
Step 2:
2 mol H2O/2 = 1 mol H2O available
2 mol O2/1 = 2 mol O2 available
Step 3:
Since less water is available, it is the limiting reactant. Oxygen gas is the excess reactant.
24 L O218 g H2O
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40 In this example, the ____ is the limiting reagent.
A HydrogenB Oxygen
Before reaction10H2 and 7 O2
After reaction10 H2 O and 2O2
C water
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40 In this example, the ____ is the limiting reagent.
A HydrogenB Oxygen
Before reaction10H2 and 7 O2
After reaction10 H2 O and 2O2
C water
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A
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41 In this example _______ is the excess reagent.
A Hydrogen
B Oxygen
C Water Before reaction10H2 and 7 O2
After reaction10 H2 O and 2O2
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41 In this example _______ is the excess reagent.
A Hydrogen
B Oxygen
C Water Before reaction10H2 and 7 O2
After reaction10 H2 O and 2O2
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B
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42 When 33 L of nitrogen gas react with 12 grams of hydrogen gas to make ammonia @STP, the hydrogen gas will be the excess reactant.
TrueFalse
N2(g) + 3H2(g) --> 2NH3(g)
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42 When 33 L of nitrogen gas react with 12 grams of hydrogen gas to make ammonia @STP, the hydrogen gas will be the excess reactant.
TrueFalse
N2(g) + 3H2(g) --> 2NH3(g)
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True
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43 When 120 grams of zinc react with 2.1 moles of H+ ion, the zinc will limit the reaction. TrueFalse Zn(s) + 2H+(aq) --> Zn2+ + H2(g)
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43 When 120 grams of zinc react with 2.1 moles of H+ ion, the zinc will limit the reaction. TrueFalse Zn(s) + 2H+(aq) --> Zn2+ + H2(g)
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False
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44 When 120 grams of zinc react with 2.1 moles of H+ ion, the zinc will limit the reaction. TrueFalse
Zn(s) + 2H+(aq) --> Zn2+ + H2(g)
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44 When 120 grams of zinc react with 2.1 moles of H+ ion, the zinc will limit the reaction. TrueFalse
Zn(s) + 2H+(aq) --> Zn2+ + H2(g)
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False
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Real World Application
In your car engine, octane is combusted with oxygen to produce carbon dioxide and water (the exhaust).
The mix of octane to oxygen must be right on or the mix is too rich (too much octane) or too lean (too little octane).
If 0.065 L of oxygen is being mixed with 0.0061 L of octane @ STP, calculate if the mixture is running lean or running rich?
0.065 L x 1 = 0.0029 mol O2 0.0061 L x 1 = 0.00027 mol octane
0.0029/25 = 0.000116 O2 av. 0.00027 mol/2 = 0.00014 mol octane av.
Theoretical yield - the amount of product that could form during a reaction; it is calculated from a balanced chemical equation and it represents the maximum amount of product that could be formed from a given amount of reactant.
Actual yield - the amount of product that forms when a reaction is carried out in the laboratory. It is measured in the lab.
Why is the actual yield different from the percent yield?
Percent yield - the ratio of the actual yield to the theoretical yield for a chemical reaction expressed as a percent; it is a measure of the efficiency of a reaction
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Theoretical Yield and % Yield
Theoretical Yield:
Maximum amount of product that could be made.
Limited by the amount of the limiting reactant.
% Yield:
The ratio of actual amount produced in the laboratory to the theoretical amount that could have been produced.
Expressed as: Actual Yield x 100
Theoretical Yield
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Calculating the Theoretical YieldExample:
Find the theoretical yield (in g) of AlCl3, if 27g Al and 71g Cl2 react.
2Al(s) + 3Cl2(g) --> 2AlCl3(s)
Step 1: Determine the limiting reactant
27 g Al x 1 mol = 1 mol Al 71 g Cl2 x 1 mol = 1 mol Cl2
27 g 71 g
1 mol Al/2 = 0.50 mol Al available 1 mol Cl2/3 = 0.33 mol Cl2 available Cl2 Limits
Step 2: Use INITIAL amount of Cl2 and stoichiometry to determine yield of desired product.
1 mol Cl2 x 2 mol AlCl3 x 133 g AlCl3 = 87.8 g
3 mol Cl2 1 mol AlCl3
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The efficiency of a reaction can be expressed as a ratio of the actual yield to the theoretical yield.
For example, a percent yield of 85% shows that the reaction conditions are more favorable than with a percent yield of only 55%.
Percent yield is the ratio comparing the amount actually obtained (actual yield) to the maximum amount that was possible (theoretical yield).
Percent Yield = x 100
Percent Yield
Actual YieldTheoretical Yield
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Calculating Theoretical Yield and % Yield
Example: A student burns 24 grams of methane with 30 L of oxygen gas in the laboratory and produces 12.1 L of carbon dioxide gas at STP. What is the % yield?
CH4(g) + 2O2(g) --> CO2(g) + 2H2O(g)
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Calculating Theoretical Yield and % Yield
Step 1: Find the LR
24 g CH4 x 1 mol = 1.5 mol CH4 30 L O2 x 1 mol = 1.33 mol O2
16 g 22.4 L
1.5 mol CH4/1 = 1.5 mol CH4 av. 1.33 mol O2/2 = 0.67 mol O2 av.
O2 is LR
Step 2: Find the theoretical yield (in L) using INITIAL amount of oxygen gas
1.33 mol O2 x 1 mol CO2 x 22.4 L = 19.8 L CO2
2 mol O2 1 mol
Step 3: Calculate the % Yield
12.1 L CO2 Actual yield x 100 = 61.1% yield
19.8 L CO2 Theoretical yield
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45 What is the theoretical yield of phosphorus pentachloride if 2 grams of phosphorus trichloride react with 1.5 moles of chlorine gas @STP?
PCl3(g) + Cl2(g) --> PCl5(g)
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45 What is the theoretical yield of phosphorus pentachloride if 2 grams of phosphorus trichloride react with 1.5 moles of chlorine gas @STP?
PCl3(g) + Cl2(g) --> PCl5(g)
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3.04
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46 At STP, what volume of laughing gas (dinitrogen monoxide) will be produced from 50 grams of nitrogen gas and 75 grams of oxygen gas? Remember to first write a balanced equation.
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46 At STP, what volume of laughing gas (dinitrogen monoxide) will be produced from 50 grams of nitrogen gas and 75 grams of oxygen gas? Remember to first write a balanced equation.
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40.1
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47 How many atoms of silver will be produced when 100 grams of copper react with 200 grams of silver nitrate?
Cu(s) + 2 AgNO3(aq) --> Cu(NO3)2(aq) + 2 Ag(s)
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47 How many atoms of silver will be produced when 100 grams of copper react with 200 grams of silver nitrate?
Cu(s) + 2 AgNO3(aq) --> Cu(NO3)2(aq) + 2 Ag(s)
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7.08 x 1023
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48 In the thermite reaction, aluminum reacts with iron(III)oxide to produce aluminum oxide and solid iron. If, when 258 grams of Al react with excess rust to produce 464 grams of pure iron, what is the % yield? (Remember, first write a balanced equation)
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48 In the thermite reaction, aluminum reacts with iron(III)oxide to produce aluminum oxide and solid iron. If, when 258 grams of Al react with excess rust to produce 464 grams of pure iron, what is the % yield? (Remember, first write a balanced equation)
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87%
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49 If 34 grams of ethane react with 84 L of oxygen gas to produce an actual yield in the laboratory of 2.9 moles of water vapor, what is the % yield?
2C2H6(g) + 7O2(g) --> 4CO2(g) + 6H2O(g)
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49 If 34 grams of ethane react with 84 L of oxygen gas to produce an actual yield in the laboratory of 2.9 moles of water vapor, what is the % yield?
2C2H6(g) + 7O2(g) --> 4CO2(g) + 6H2O(g)
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91%
Slide 99 (Answer) / 109
50 Given the equation below, how many liters of sulfur dioxide would be actually produced if 55 grams of zinc sulfide were reacted with excess oxygen @STP and produced a 75% yield?
2ZnS(s) + 3O2(g) --> 2 SO2(g) + 2ZnO(s)
Slide 100 / 109
50 Given the equation below, how many liters of sulfur dioxide would be actually produced if 55 grams of zinc sulfide were reacted with excess oxygen @STP and produced a 75% yield?
2ZnS(s) + 3O2(g) --> 2 SO2(g) + 2ZnO(s)
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Ans
wer
9.5
Slide 100 (Answer) / 109
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Calculating Excess Reactants
Slide 101 / 109
Calculating Excess Reactant
There will always be a certain amount of excess reactant remaining. The following steps are useful in determining how much of the excess reactant is left over.
Step 1: Use the limiting reactant to determine how much of the excess reactant was required to react.
Step 2: Subtract the amount of excess reactant used from the initial amount.
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Calculating Excess Reactant
Example: If 6 grams of hydrogen gas react with 160 grams of oxygen gas, how much of the excess reactant remains?
51 How many grams of the excess reactant remain if 400 grams of nitrogen gas are reacted with 800 grams of oxygen gas according to the reaction below? (Don't forget to balance first!)
___N2(g) + ___O2(g) --> ___N2O5(g)
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51 How many grams of the excess reactant remain if 400 grams of nitrogen gas are reacted with 800 grams of oxygen gas according to the reaction below? (Don't forget to balance first!)
___N2(g) + ___O2(g) --> ___N2O5(g)
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Ans
wer
120.4
Slide 105 (Answer) / 109
52 Methanol (CH3OH) can be synthesized from carbon monoxide and hydrogen gas. If 152 kg of carbon monoxide gas is reacted with 1500 L of H2 gas @STP, how many liters of the excess reactant remain? (Remember to first write a balanced reaction!)
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52 Methanol (CH3OH) can be synthesized from carbon monoxide and hydrogen gas. If 152 kg of carbon monoxide gas is reacted with 1500 L of H2 gas @STP, how many liters of the excess reactant remain? (Remember to first write a balanced reaction!)
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Ans
wer
120,850
Slide 106 (Answer) / 109
Credit to Tom GreenboweChemical Education Group at Iowa State University
Slide 107 / 109
Calcium hydroxide, Ca(OH)2 , is also known as “slaked lime” and it is produced when water reacts with “quick lime,” CaO. If you start with 2.4 kg of quick lime, add excess water, and produce 2.06 kg of slaked lime, what is the percent yield of the reaction?
Stoichiometry Practice Problem
Is this a limiting reagent problem?Is the 2.06 kg a theoretical yield or actual yield?
What quantity must you solve for?Did you write a balanced equation?