Bell Ringer 10-27-14
Write the Question and the Answer!!
14 grams of iron react with 8 grams of
sulfur. The final product is iron sulfide.
1. How many grams of iron sulfide are
produced in the reaction?
a. 6 grams
b. 14 grams
c. 22 grams
d. 112 grams
2. What are the reactants of the
chemical reaction?
3. What is the product of this chemical
reaction?3
MYP Question: How can such a small thing impact our environment in
such a big way?
Area of interaction: Environment
Learner profile words: Communicators, inquirers, knowledgeable
Standard:
S8P1. Students will examine the scientific view of the nature of matter.
g. Identify and demonstrate the Law of Conservation of Matter.
Learning Target: Today I will be learning how to use my understanding of
mathematical equations, to show that the number of atoms at the start of
a reaction MUST equal the number of atoms at the end, this is important
because what I start with is what I end with t least in a closed system
chemical reaction
Homework: Study for Exam on Thursday- get Ian notebook ready for
pickup
Opening
Look at the Harry
Potter video and
decide if the
following scenario
is possible (based
on what you know
about The Law of
Conservation of
Matter).
Work Session When a chemical reaction occurs, it can be
described by an equation.
The chemicals can be represented by their names or by their chemical symbols.
Unlike mathematical equations, the two sides are separated by an arrow, that indicates that
the reactants from the products .
C + O2 CO2
Carbon + Oxygen Carbon Dioxide
How to Tell if Your Equation is
Balanced
How to Read Chemical
Equations.
2Na + Cl2 2NaCl
Coefficients –Whole numbers in front of
compounds. It tells you the quantity or number
of molecules of the compound.
ex. 2 NaCl (NaCl + NaCl) =
2 - Na and 2 -Cl atoms
Ex. 2H2SO4 – 2 molecules of Sulfuric Acid
A coefficient is distributed to ALL elements in a
compound
2 – H2 (for a total of 4 H atoms)
2 – S (for a total of 2 S atoms)
2 – O4 (for a total of 8 O atoms)
Balancing is done by placing coefficients in front
of the formulas to insure the same number of
atoms of each element on both sides of the arrow.
Coefficients
How to Read Chemical
Equations.
Fe + O2 Fe2O3
Subscripts – small numbers following
elements. It tells you the number of
atoms of a particular elements.
*When balancing equations subscripts cannot be
changed.
ex. H2O = 2 -H’s , 1- O
Step by Step Instructions
Glue onto IAN pg 1) Decide which formula represents the
reactants.
2) Count the number of each atom represents
in the reactants.
3) Decide which formula represents the
products.
4) Count the number of each atoms present in
products.
5) Compare the two to see if the equation is
balanced.
Practice
Propane burns. Propane combines with oxygen in the
air to make carbon dioxide and water vapor. This
chemical reaction takes place when a “gas” grill is
used for cooking.
CH3 + 2O2 CO2 + 2H2O
Which chemical formula(s) represents the
reactants?
Which chemical formula(s) represents the
products?
How many of each atom is present in the
reactants?
C -
H -
O -
How many of each atom is present in the products?
C -
H -
O -
Is this a balanced equation? Explain.
Practice sheet
• You will have 10 minutes to work
individually to complete the worksheet.
• After 10 minutes you will have 5 minutes
to compare your answers with your elbow
partners. Discuss any differences you
find.
Closing- Exit Ticket
Create one question that you would
like to see on Thursdays test.
Test your elbow partner to see if
they know the answer.
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