Vocabulary
hint: usually tells us how many molecules we have of something.
Coefficient
4Fe + 3O2 ---->2Fe2O3
How many atoms of oxygen do you have on the reactants side?
6
Properties remain the same and can change the form of a substance without changing the identity.
ex. Boiling, cracking, bending
Physical Change
created, destroyed, rearranged
2H2 + O2 -----> 2H2O
Is this equation balanced?
yes
The small number after the letters. Usually telling us how many atoms we have.
Subscript
4Fe + 3O2 ----> Fe2O3
How many atoms of Iron (Fe) do you have on the products side?
2
Changes the identity of a substance and a new substance is produced.
ex. rotting, decomposing, exploding
Chemical change
Everything to the left side of the arrow is called _________?
Reactants
KClO3 -----> KCl + O2
Is this equation balanced?
No
This is identified by an arrow separating the right and left sides of a chemical equation.
yield
CH4 + 2O2 --------> CO2 + 2H2O
How many molecules of Water (H2O) do you have?
2
Group the following into chemical or physical:
viscosity
reactivity
density
solubility
tarnishing
rusting iron
dissolving in water
melting wax
burning a log
grinding spices
Physical: viscosity, density, solubility, dissolving in water, melting wax, grinding spices
Chemical: reactivity, tarnishing, rusting iron, burning a log
Everything to the right side of the arrow is called _________?
Products
KClO3 -----> KCl + O2
Balance the equation
2 KClO3 -----> 2 KCl + 3 O2
the ability of a substance to undergo changes in identity and new substance produced.
Chemical Property
CH4 + 2O2 --------> CO2 + 2H2O
How many molecules of of Carbon Dioxide (CO2) do you have?
1
a. A baker adds yeast to dough, which releases gas and causes the dough to rise.
b. A piece of chocolate is melted in a hot pan.
c. Mixing two clear liquids results in a cloudy white solid settling at the bottom.
d. A metal railing is left outside and develops a reddish-brown, flaky coating.
a. chemical
b. physical
c. chemical
d. chemcial
H₂ + O₂ → H₂O
Draw the model for this equation.
Teacher will draw the answer on the board
Fe + O2 ----> Fe2O3
Balance the equation.
4 Fe + 3 O2 ----> 2 Fe2O3
can be observed without changing the identity of a substance.
Physical Property
CH4 + 2O2 --------> CO2 + 2H2O
How many atoms of each element do you have? How many do you have total on the product and reactant sides?
Product: C= 1 H=4 O=4
Total: Reactant: 9 Product: 9
Give an example of when a chemical change has occurred.
change in color or odor
formation of a gas
formation of a precipitate (solid)
change in light or heat
CH₄ + O₂ → CO₂ + H₂O
Draw the model for this equation.
Teacher will draw the answer on the board
C3H8 + O2 -----> CO2 + H2O
Balance the equation.
C3H8 + 5 O2 -----> 3 CO2 + 4 H2O