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.