Name
Skill Development/Guided Practice 1
The Law of Conservation of Matter states that in a chemical reaction
the number of atoms is conserved no matter how they are arranged.
1. Two copper (Cu) molecules reacted with
one molecule of oxygen (O2) to yield two
molecules of copper oxide.
2Cu +
O2
2CuO
2. Two molecules of sodium (Na) reacted
with one molecule of chlorine (Cl2) to form
two molecules of sodium chloride (NaCl).
2Na
__ copper + __ oxygen
=
__ copper + __ oxygen
+
Cl2
2NaCl
__ sodium + __ chlorine
=
__ sodium + __ chlorine
3. One molecule of methane (CH4) reacted
with two molecules of oxygen (O2) to
produce one molecule of carbon dioxide
(CO2) and two molecules of water (H2O).
4. Two molecules of iron (Fe) reacted with
three molecules of chlorine (Cl2) to form
two molecules of iron trichloride (FeCl3).
CH4 + 2O2
2Fe
CO2 +
2H2O
__ carbon + __ hydrogen + __ oxygen
=
__ carbon + __ hydrogen + __ oxygen
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+
3Cl2
2FeCl3
__ iron + __ chlorine
=
__ iron + __ chlorine
Describe the law of conservation of matter.
4-5
Skill Development/Guided Practice (continued)
The Law of Conservation of Matter states that in a chemical reaction the number of atoms is
conserved no matter how they are arranged.
Research #1: The Law of Conservation of Matter
Chemistry is cool, but it is not magic. According to the law of conservation of matter, matter can
neither be created nor destroyed. Essentially, this means that atoms themselves cannot be created
or destroyed. In a chemical reaction, whatever atoms are present at the beginning of a reaction,
must also be present in the products of the reaction. The only difference between the reactants and
products, then, is the arrangement of the chemical bonds between atoms, not the atoms
themselves. Below is the chemical equation for the reaction that forms rust.
4Fe + 3O2 —> 2Fe2O3
In the reaction, there are four iron (Fe) atoms on the reactant side and four on the product side.
There are six oxygen (O) atoms on the reactant side and six on the product side.
Research #2: The Law of Conservation of Matter
The Law of Conservation of Matter states that matter can neither be created or destroyed, but
can be changed in form. To understand this law, you can think in terms of the atoms themselves.
Take the reaction between hydrogen and oxygen. The product of this reaction is water. The
unbalanced chemical equation for this reaction is H2 + O2 —> H2O
If you count up the number of hydrogen atoms on each side, then you find that each side has
two hydrogen atoms each. Now count up the oxygen atoms on each side of the chemical equation.
The left side of the equation has two oxygen atoms and the right side has only one. This
unbalanced chemical equation does not obey the Law of Conservation of Matter.
Now let's look at the balanced equation. 2H2 + O2 —> 2H2O. If you recount the number of
atoms on each side for each substance, then you have four atoms of hydrogen (H) and four atoms
of oxygen. Here both sides are equal. This balanced equation obeys the Law of Conservation of
Matter.
Description
Research #1
Research #2
Both
1. Gives examples of balanced chemical equations.
2. Gives example of an unbalanced chemical
equation.
Why do the balanced chemical equations prove the Law of Conservation of Matter?
Why does the unbalanced chemical equation not obey the Law of Conservation of Matter?
Write a definition for the Law of Conservation of Matter. Use your own words.
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Describe the law of conservation of matter.
6-9
Skill Development/Guided Practice (continued)
The Law of Conservation of Matter states that in a chemical reaction
the number of atoms is conserved no matter how they are arranged.
5. Ag + S
Ag2S
6. 4Fe
+
3O2
2Fe2O3
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
6. Ca(OH)2 + 2HCl
CaCl2 + 2H2O 7. C6H12O6
2C2H5OH + CO2
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
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Describe the law of conservation of matter.
10
Name
Independent Practice
The Law of Conservation of Matter states that in a chemical reaction the number of atoms is
conserved no matter how they are arranged.
Laboratory – What happens when baking soda is mixed with vinegar?
http://www.andybrain.com/sciencelab/2007/11/22/a-classic-easy-chemical-reactionwith-baking-soda-and-vinegar/
Baking Soda + Vinegar = ???
Baking soda is a fabulous ingredient to clean with. Pots and pans scrubbed clean in an
instant. Bathtubs shine. Vinegar is also a stellar cleaning tool. Countertops are clean and
disinfected, and glasses are rinsed sparkly clean.
You’d think, putting these two hard-hitting ingredients together would leave you with
something no man-made cleaner could touch, right?
What childhood would be complete without the baking soda and vinegar volcano science
project? Remember how it exploded up into a creamy, bubbly, overflowing blob? Well, what
happened is that a chemical reaction took place.
The vinegar or acetic acid reacts with sodium bicarbonate (baking soda). The bubbles you
see from the reaction come from the carbon dioxide. What’s left is a dilute solution of sodium
acetate in water. In fact, it’s almost all water. That’s not going to get your counters very clean.
C2H4O2 + NaHCO3
acetic
acid
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baking
soda
NaC2H3O2 + H2O
sodium
acetate
water
+ CO2
carbon
dioxide
Describe the law of conservation of matter.
13
Access Concepts and Experimentation
When a match is lit, sulfur (S) reacts with oxygen (O2) in the air to release energy
and form sulfur dioxide (SO2). Which is a true statement about this chemical
reaction?
S + O2
Answer
SO2
Justify your answer
a. two molecules of oxygen
react with one molecule of
sulfur
b. two molecules of sulfur oxide
are produced
c. the molecules in the
reactants and the products
contain the same number of
atoms of sulfur and oxygen
d. the molecules in the
reactants and the products
contain different numbers of
atoms of sulfur and oxygen
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Describe the law of conservation of matter.
14
Access Concepts and Experimentation
Determine which chemical reactions obey the Law of Conservation of Matter.
Justify your answer.
Description
Obeys the Law
of
Conservation
of Matter
Does not obey
the Law of
Conservation
of Matter
Justify your answer.
Four molecules of sodium (Na) react with
one molecule of oxygen (O2 ) to produce
one molecule of sodium oxide (Na2O).
4Na + O2 –> 2 Na2O
One molecule of carbon (C) is added to
one molecule of hydrogen (H2 ) to
produce one molecule of methane (CH4)
and one molecule of chlorine (Cl2).
C + H2 –> CH4 + Cl2
One molecule of nitrogen (N2 ) reacts
with three molecules of hydrogen (H2) to
produce one molecule of ammonia (NH3).
N2 + 3H2 –> NH3
Two molecules of aluminum oxide (Al2O3)
produce four molecules of aluminum (Al )
and three molecules of oxygen (O2).
2 Al2O3 –> 4Al + 3O2
Acetylene gas is mixed with air at the
burner and combusts producing a bright
white flame. The products of the reaction
are carbon dioxide and water vapor.
2 C2H2 + 5 O2 –> 4 CO2 + 2H2O
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Describe the law of conservation of matter.
15
Access Concepts and Experimentation
Have you ever prepared meat on a propane grill? The meat placed over the burner
is cooked with the help of heat energy released after the burning of propane gas
(C3H8). When propane is burned with the help of oxygen (O2), it gives off heat
energy, water (H2O), and carbon dioxide (CO2).
C3H8 + 5O2
3CO2 + 4H2O
Answer
Justify your answer
a. The oxygen in the reactants
rearranges to produce only
water.
b. The reaction produces five
molecules of oxygen and
four molecules of water.
c. All the molecules in the
reactants and the products
contain oxygen.
d. The atoms in propane and
oxygen rearrange to
produce carbon dioxide and
water.
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Describe the law of conservation of matter.
16
Whiteboard Insert
Ac - Actinium
Ag - Silver
Al - Aluminum
Am - Americium
Ar - Argon
As - Arsenic
At - Astatine
Au - Gold
B - Boron
Ba - Barium
Be - Beryllium
Bh - Bohrium
Bi - Bismuth
Bk - Berkelium
Br - Bromine
C - Carbon
Ca - Calcium
Cd - Cadmium
Ce - Cerium
Cf - Californium
Cl - Chlorine
Cm - Curium
Cn - Copernicium
Co - Cobalt
Cr - Chromium
Cs - Cesium
Cu - Copper
Db - Dubnium
Ds - Darmstadtium
Dy - Dysprosium
Er - Erbium
Es - Einsteinium
Eu - Europium
F - Fluorine
Fe - Iron
Fl - Flerovium
Fm - Fermium
Fr - Francium
Ga - Gallium
Gd - Gadolinium
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Ge - Germanium
H - Hydrogen
He - Helium
Hf - Hafnium
Hg - Mercury
Ho - Holmium
Hs - Hassium
I - Iodine
In - Indium
Ir - Iridium
K - Potassium
Kr - Krypton
La - Lanthanum
Li - Lithium
Lr - Lawrencium
Lu - Lutetium
Lv - Livermorium
Md - Mendelevium
Mg - Magnesium
Mn - Manganese
Mo - Molybdenum
Mt - Meitnerium
N - Nitrogen
Na - Sodium
Nb - Niobium
Nd - Neodymium
Ne - Neon
Ni - Nickel
No - Nobelium
Np - Neptunium
O - Oxygen
Os - Osmium
P - Phosphorus
Pa - Protactinium
Pb - Lead
Pd - Palladium
Pm - Promethium
Po - Polonium
Pr - Praseodymium
Pt - Platinum
Pu - Plutonium
Ra - Radium
Rb - Rubidium
Re - Rhenium
Rf - Rutherfordium
Rg - Roentgenium
Rh - Rhodium
Rn - Radon
Ru - Ruthenium
S - Sulfur
Sb - Antimony
Sc - Scandium
Se - Selenium
Sg - Seaborgium
Si - Silicon
Sm - Samarium
Sn - Tin
Sr - Strontium
Ta - Tantalum
Tb - Terbium
Tc - Technetium
Te - Tellurium
Th - Thorium
Ti - Titanium
Tl - Thallium
Tm - Thulium
U - Uranium
Uuo - Ununoctium
Uup - Ununpentium
Uus - Ununseptium
Uut - Ununtrium
V - Vanadium
W - Tungsten
Xe - Xenon
Y - Yttrium
Yb - Ytterbium
Zn - Zinc
Zr - Zirconium
Describe the law of conservation of matter.
17