Hydrate Lab Cu(SO4) . 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?

Hydrate Lab Cu(SO4) . H2O ----> Cu(SO4) + H2O

Copper Sulfate Hydrate

Bell Ringer1. Calculate the percent composition of water in this

hydrate: Mg(SO4) . 7H2O (Epsom Salt)

2. N2 + H2 ----------> 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) . 7H2O -----> 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 ObjectivesChapter 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 + H2Oa. 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 + H2Oa. 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 + 2H2Oa. 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 + 4H2OHow many grams of CO2 are produced when 6.2

grams of C3H8 combusts with oxygen?

Mass to Mass Stoichiometry Conversions

Mass of given

substance

Moles of given

substance

Moles of wanted

substance

Mass of wanted

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)

A -----> B + CConvert from grams of substance A to grams of substance B.

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 LabPurpose: 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. Reactant4. 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 molesCalculate % yield of AlCl3:

Stoichiometry: Percent Yield4. 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 C2H2 + O2 --- CO2 + H2O1. Balance the equation if needed.2. If 2.40 moles of C2H2 reacts with 7.40 moles of

O2 how many grams of water can be produced?a. What is the limiting reactant?b. Use limiting reactant to calculate theoretical

yield of H2O in grams.c. If the actual yield of H2O in the lab was 40.1

grams, calculate what the % yield of H2O would be.