Transcript Objectives: SWBAT 01/30/07

Objectives:
 Use Stoichiometry to determine the
amount, mass or volume of a
substance produced or required in a
chemical reaction
Drill:
 Complete the first 2 columns of a KWL chart on
stoichiometry.
What I Know
What I Want to
Know
What I Learned
Homework:
 None
Chapter Challenge
Create a prototype of a
“Chemical Dominoes
Sequence” that can be sold
by a toy company to 10-15
year old children
Activity 3
How Much Gas is Produced?
What do you see?
 Look at the picture on page 274 while I read
the poem.
 How does this poem and picture relate to the
chemistry you have learned?
What do you see?
Take a minute to look at the
picture while I read the poem on
page 274 in the textbook. Be
prepared to discuss with the
class.
What do you think?
Suppose you have decided that you want to
inflate a balloon to a volume of 50mL with
carbon dioxide as part of your Chemical
Dominoes apparatus
 What information would you need to predict
how much of the reactants you would need?
 How could you use that information to
determine the final volume of the balloon?
Investigate
Pages 274 – 278
Chem Talk
Stoichiometry
Mole
A counting word that is used to
count very large quantities
23
 1 mol = 6.02 x 10

6.02 x 1023 molecules
1 mole
Chem Talk
Stoichiometry
Molar
Mass
The mass of one mole of
particles
 Molar mass of CO2

1 x 12.011 g
+ 2 x 15.9994 g
44.010 g
Chem Talk
 Mole to Mole Relationships
 The
coefficients in a balanced chemical
equation represent a mole to mole
relationship

Ba(OH)2 + H2SO4  BaSO4 + 2H2O
2 moles H2O
1 mole Ba(OH)2
Chem Talk
 Molar Volume of a Gas
 One
mole of any gas at Standard
Temperature and Pressure (STP) will be
22.4 L
22.4 L CO2
1 mole CO2
Chem Talk
Standard Temperature and
Pressure (STP)
 Pressure = 1 atm or 760 mmHg
 Temperature = 0ºC or 273K
Chem Talk
 Stoichiometry Calculations
 Dimensional Analysis process that
utilizes the conversion factors of
stoichiometry
 Mass to mole (from P.T.)
 Volume to mole (22.4 L/mol)
 Particle to mole (Avogadro’s #)
 Mole to mole (from BCE)
Mass to mass example
CaCO3 + 2HCl  CaCl2 + CO2 + H2O
What mass of CO2 would be produced from 5.0 g of
HCl?
Mass to Volume example
CaCO3 + 2HCl  CaCl2 + CO2 + H2O
What volume of CO2 would be produced from 35.0 g of
CaCO3?
Particle to Mass example
CaCO3 + 2HCl  CaCl2 + CO2 + H2O
What mass CaCl2 would be produced from 12.0 x 1024
molecules of HCl?
What do You Think Now?
At the beginning of this activity you were asked what
was meant by the word “balance”
What information would you need to predict how much
of the reactants you would need?
 How could you use that information to determine the
final volume of the balloon?
 How would you answer these questions now that you
have completed this activity?
Chem Essential Questions
 What does it mean?
 Macro

In this activity, you developed a method for
determining an unknown number of pennies
without counting them. Explain how the mole
concept is similar to buying a bag of flour
without counting the particles of flour.
Chem Essential Questions
 What does it mean?
 Nano

On a molecular level, describe what is
happening when two substances react to for a
new product
Chem Essential Questions
 What does it mean?
 Symbolic
 Describe the information provided in the
symbolic notation of a chemical equation.
 Can you make an equivalent domino with
any two units? Explain why or why not?
Chem Essential Questions
 How do you know?
 At
the beginning of this activity you
carried out an activity using pennies.
Explain how this activity relates to
stoichiometry?
Chem Essential Questions
 Why do you believe?


One example of stoichiometry used in the
real world is in recipes. Different amounts
of certain ingredients must be combined
together to produce a certain amount of
food.
Describe another real-life application of
stoichiometry
Chem Essential Questions
 Why should you care?



Some of the requirements of the Chapter
Challenge are that the sequence of events
be reliable, repeatable and safe.
Describe how stoichiometry will be important
in ensuring that these three requirements are
met.
What might be the consequences of forming
too much product?
Reflecting on the Activity and
the Challenge
Page 284
Inquiring Further Activity – Page 286
Limiting Reagent – the reactant used
up first in a reaction
 Design an experiment to determine
whether it matters which of the two
starting materials, baking soda or
acetic acid, is the limiting reagent.