Cu(SO4)
.
Hydrate Lab
H2O ----> Cu(SO4) + H2O
Use the equation above to help answer the
following questions:
1.What is the hydrate salt in this equation?
2.What is the anhydrous salt in this equation?
3.What is the difference between a hydrated salt
and an anhydrous salt?
4.Is this a physical or chemical reaction?
Cu(SO4)
.
Hydrate Lab
H2O ----> Cu(SO4) + H2O
Copper Sulfate Hydrate
Bell Ringer
1. Calculate the percent composition of water in this
hydrate: Mg(SO4)
2. N2
+
H2
. 7H O
2
---------->
(Epsom Salt)
NH3
a. What type of chemical reaction is this?
b. Balance the chemical equation.
c. What does this balanced chemical equation tell you?
Bell Ringer: Hydrates (1,3)
1. Answer these questions pertaining to the following
equation: Mg(SO4)
. 7H O ----->
2
Mg(SO4) + H2O
a. What is the chemical formula of the hydrate?
b. What is the chemical formula for the anhydrous salt?
c. What is the mole ratio of salt to water in the hydrate?
d. What is the percent composition of water in the hydrate?
Infinite Campus Update
• Hydrate Lab: today, May 3rd
• Lab Report-final draft: by Monday, May 7th
• Stoichiometry Quiz: Monday, May 7th
Infinite Campus Update
• Hydrate Lab: today, May 3rd
• Famous Scientist Rough Draft: by Monday, May 7th
• Stoichiometry Quiz: Monday, May 7th
Infinite Campus Update
• Lab Report-final draft: by Monday, May 7th
• Stoichiometry Quiz: Monday, May 7th
Infinite Campus Update
• Hydrate Lab : posted in IC
• Lab Report-final draft: by Monday, May 7th
• Stoichiometry Quiz: Monday, May 7th
Stochiometry Objectives
Chapter 12
1. I can explain why it is important to balance
chemical equations.
2. I can convert between substances in a balanced
chemical equation using mole conversions.
Balancing and Interpreting Chemical Equations
N2 +
H2 ---------->
NH3
1. What type of chemical reaction is this?
2. Balance the chemical equation.
3. What does this balanced chemical equation tell
you?
Balancing and Interpreting Chemical Equations
N2 +
3H2 ---------->
2NH3
1. a. According to the equation how many moles of
NH3 is produced?
b. How many moles of N2 are needed to produce
8.0 moles of NH3?
Stoichiometry (1, 2nd)
H2O ----------> H2 +
O2
1. What type of reaction is this?
2. Balance the chemical equation if needed.
3. Interpret the chemical equation using moles?
4. If you start with 100 moles of H2O how many
moles of H2 would be produced?
Stoichiometry
N2 +
3H2 ---------->
2NH3
• Converting between substances in a balanced
chemical equation using mole conversions.
Bell Ringer: Stoichiometry
•
N2H4 + O2 -----> N2 + H2O
a. Balance the equation.
b. How many moles of N2H4 (rocket fuel) are present
in the chemical equation?
c. If 5.6 moles of rocket fuel reacted with oxygen
how many moles of nitrogen and water do you
predict would be produced?
d. If 13.8 grams of water were produced how much
rocket fuel in grams would have been used up?
Bell Ringer: Stoichiometry
•
N2H4 + O2 -----> N2 + H2O
a. Balance the equation.
b. How many moles of N2H4 (rocket fuel) are present
in the chemical equation?
c. If 5.6 moles of rocket fuel reacted with oxygen
how many moles of nitrogen and water do you
predict would be produced?
Bell Ringer: Stoichiometry
•
N2H4 + O2 -----> N2 + 2H2O
a. If 13.8 grams of water were produced how much
rocket fuel in grams would have been used up?
Stoichiometry:
Balancing and Interpreting Chemical Equations
N2 +
H2 ---------->
NH3
1. What type of chemical reaction is this?
2. Balance the chemical equation.
3. What does this balanced chemical equation tell
you?
Stoichiometry
N2
+
3H2
---------->
2NH3
Stoichiometry:
• Converting between substances in a balanced
chemical equation using mole conversions.
Balancing and Interpreting Chemical Equations
N2 +
3H2 ---------->
2NH3
1. a. According to the equation how many moles of
NH3 is produced?
b. How many moles of N2 are needed to produce
8.0 moles of NH3?
Mole-Mole Stoichiometry Conversions
A -----> B + C
Convert from moles of substance A to moles of substance B.
Moles of
given
substance
Moles of
wanted
substance
mole given to mole wanted ratio
(balanced equation)
One step conversion:
Convert from moles of given substance to moles of
wanted substance using the balanced equation.
Stoichiometry:
Mole to Mole Conversions
Stoichiometry Problems:
C3H8 + 5O2 ------->
3 CO2
+ 4H2O
How many grams of CO2 are produced when 6.2
grams of C3H8 combusts with oxygen?
Mass to Mass Stoichiometry Conversions
A -----> B + C
Convert from grams of substance A to grams of substance B.
Mass of
given
substance
Moles of
Moles of
Mass of
given
wanted
wanted
substance
substance
substance
mass to mol of given
mol given to mol wanted
mol to mass of wanted
(molar mass conversion)
(balanced equation)
(molar mass conversion)
Three Step Conversion:
1. Convert grams of given to moles using the molar
mass conversion. (1 mole = molar mass of given)
2. Convert moles of given to moles of wanted using
the balanced equation.
3.Convert moles of wanted to grams using the molar
mass conversion. (1 mole = molar mass of wanted)
Stoichiometry:
Mass to Mass Conversions
Stoichiometry:
Mass to Mass Conversions
Stoichiometry
HCl + Mg -------> MgCl2 + H2
1.What type of reactions is this?
2.Balance the equation if needed.
3.If 6.8 moles of Mg react with 7.5 moles of HCl, how
many moles of MgCl2 would be produced?
Limiting Reagent Demonstration Lab
Purpose: Illustrate the concept of a limiting
reactant in a chemical reaction.
Procedures: Add different amounts of magnesium
strips to 13mL of 1.0 M hydrochloric acid.
Data: What did you observe from the demonstration?
Conclusion: What is the limiting and excess reactant in
this reaction?
Stoichiometry: Limiting Reactants
• Limiting Reactant:
• Excess Reactant:
en.wikipedia.org
Stoichiometry: Limiting Reactants
• Limiting Reactant: completely consumed
• Excess Reactant: partially consumed
en.wikipedia.org
Stoichiometry: Limiting Reactant
HCl + Mg -------> MgCl2 + H2
1. What type of reactions is this?
2. Balance equation if needed.
3. If 6.8 moles of Mg react with 7.5 moles of HCl, how
many moles of MgCl2 and H2 would be produced?
Stoichiometry: Limiting vs. Reactant
4. Limiting Reactant: Al
Theoretical Yield of AlCl3: 3.0 moles
5. Limiting Reactant: C2H4
Theoretical yield of H2O: 5.4 moles
6. Limiting Reactant: N2
Theoretical yield of NH3: 34 g
Stoichiometry: Percent Yield
% Yield of Product:
Accuracy of product formation in the lab.
% Yield of product: actual yield
x 100
theoretical yield
4. Theoretical yield of AlCl3: 3.0 moles
Actual yield from lab of AlCl3: 2.8 moles
Calculate % yield of AlCl3:
Stoichiometry: Percent Yield
4. Theoretical Yield of AlCl3: 3.0 moles
Actual yield from lab of AlCl3: 2.8 mole
% Yield of AlCl3 : 93%
5. Theoretical yield of H2O: 5.4 moles
Actual yield from lab of H2O: 4.9 moles
% Yield of H2O: 91%
6. Theoretical yield of NH3: 34 g
Actual yield from lab of NH3: 31.5 g
% yield of NH3: 92.6%
Bell Ringer: Limiting Reactants and % Yield
1.
2.
a.
b.
c.
C2H2 + O2 --- CO2 + H2O
Balance the equation if needed.
If 2.40 moles of C2H2 reacts with 7.40 moles of
O2 how many grams of water can be produced?
What is the limiting reactant?
Use limiting reactant to calculate theoretical
yield of H2O in grams.
If the actual yield of H2O in the lab was 40.1
grams, calculate what the % yield of H2O would
be.