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BELL WORK 1/20/16
ANSWER ALL 3 OF THE FOLLOWING QUESTIONS:
IS NaCl AN ELEMENT OR COMPOUND? EXPLAIN
WHAT SKILL YOU NEED TO KNOW TO SOLVE
THIS? DOES A CHEMICAL REACTION OCCUR TO
FORM NaCl?
AGENDA
1. BELL WORK
2. REVIEW CHEMICAL REACTIONS
3. INTRO CHEMICAL FORMULAS & BALANCING
EQUATIONS
4. GROUPWORK (1-3-6 PROTOCOL)
5. INDEPENDENT PRACTICE
6. EXIT TICKET (PLICKERS)
STUDENT LEARNING OBJECTIVES
SPI 0807.9.2 IDENTIFY THE COMMON OUTCOME OF ALL CHEMICAL
CHANGES
SPI 0807.9.3 CLASSIFY COMMON SUBSATNCES AS ELEMNTS OR
COMPOUNDS BASED ON THEIR SYMBOLS OR FORMULAS
SPI 0807.9.8 INTERPRET THE RESULTS OF AN INVESTIGATION TO
DETERMINE WHETHER A PHYSICAL OR CHEMICAL CHANGES HAS
OCCURRED.
SPI 0807.9.10 IDENTIFY THE REACTANTS AND PRODUCTS OF A
CHEMICAL REACTION
SPI 0807.9.11 RECOGNIZE THAT IN A CHEMICAL REACTION THE
MASS OF THE REACTANTS IS EQUAL TO THE MASS OF THE
PRODUCTS (LAW OF CONSERVATION OF MASS)
TOC: #62 CHEMICAL REACTIONS NOTES
ESSENTIAL QUESTIONS:
1. CAN I IDENTIFY THE REACTANTS AND PRODUCTS
OF A CHEMICAL EQUATION?
2. CAN I EXPLAIN THE LAW OF CONSERVATION OF
MASS?
⏏
WHAT IS A CHEMICAL REACTION?
A CHEMICAL REACTION IS THE PROCESS OF A SUBSTANCE
COMPLETELY CHANGING TO A DIFFERENT SUBSTANCE WITH
DIFFERENT PROPERTIES
WHY ARE THERE CHEMICAL REACTIONS?
CHEMICAL REACTIONS HAPPEN WHEN MOLECULES BUMP INTO EACH
OTHER CAUSING THE STARTING BONDS TO BREAK APART, THE
ATOMS REARRANGE, AND NEW BONDS ARE FORMED
EXAMPLE:
CH4 + O2 → CO2 + H2O
SAME CARBON
EXAMPLE:
Methane fire
CH4 + O2 → CO2 + H2O
Yield sign means EQUAL to
7 CLUES OF A CHEMICAL REACTION:
1. CHANGE IN COLOR
2. FORMATION OF GAS
3. SOLID FORMED CALLED PRECIPITATE
4. LIGHT IS EMITTED
5. CHANGE IN TEMPERATURE
6. CHANGE IN SMELL OR TASTE
7. IRREVERSIBLE
CHEMICAL SYMBOL - SHORTER WAY TO WRITE AN
ELEMENTS NAME.
CHEMICAL FORMULA -SHORTHAND WAY TO USE
CHEMICAL SYMBOLS AND NUMBERS TO
REPERESNT A SUBSTANCE.
A CHEMICAL FORMULA SHOWS THE NUMBER OF
ATOMS OF EACH ELEMENT IN A MOLECULE
EXAMPLES:
H2O
SO4
Ca(OH)2
CHEMICAL FORMULAS USE SUBSCRIPTS AND COEFFICIENTS
TO SHOW THE NUMBER OF ATOMS AND MOLECULES.
SUBSCRIPTS THE SMALL NUMBER TO THE RIGHT OF THE ELEMENT
THAT TELLS THE NUMBER OF ATOMS
Examples:
H2O
SO4
Ca(OH)2
COEFFICIENTS - LARGE NUMBER TO THE LEFT OF THE
ELEMENT. APPLIES TO TO THE WHOLE MOLECULE!
*Look at the molecule below. How many Hydrogen
atoms are in the molecule? How many Oxygen atoms?
2H2O
H = ____
O=_____
GROUP WORK (OF 3):
THINK, PAIR, SHARE
4SO4
S = ____
O = ____
3Ca(OH)2
Ca = ____
O = ____
H = ____
LAW OF CONSERVATION OF MASS
LAW OF CONSERVATION OF MASS STATES THAT
MASS CAN NOT BE CREATED OR DESTROYED
CHEMICAL EQUATION
CHEMICAL EQUATION IS AN EASIER AND SHORTER WAY
TO WRITE A CHEMICAL REACTION USING CHEMICAL
SYMBOLS AND FORMULAS AS A SHORTCUT TO
DESCRIBE A CHEMICAL REACTION
EXAMPLE:
CH4 + O2 → CO2 + H2O
Reactants: what you start with
Products: what you end with
An equation is balanced when the number of
atoms in the reactants are = to the number of
atoms in the products
H2O
2H2O
You balance an
equation by changing the
coefficients, not the
subscript!
4H2O
*MOVE AROUND THE ROOM
TRUE OR FALSE
Coefficients are used as multipliers against the
Subscripts to balance chemical equations.
Example #1
__ Fe + __S → __FeS
Element
Before
After
Fe = ____ _____
S = ____ _____
Example #2
__H2 + __O2 → __H2O
ELEMENT BEFORE
H=
O=
AFTER
____ _____
____ _____
Example #3
__Mg + __O2 → __MgO
Element
Before
After
Mg = ____ _____
O=
____ _____
EXIT TICKET
When balancing equations, you can NEVER change the ...
a. Coefficient
b. Subscript
c. Whole number
d. Atom
EXIT TICKET
When balancing equations, you can NEVER change the ...
a. Coefficient
b. Subscript
c. Whole number
d. Atom