Download Candle Mass Lab and the Law of Conservation of Matter Notes.

Candle Mass Lab
and
the Law of Conservation of Matter Notes.
Chapter 7.1
Describing Chemical Reactions
• What I
Expect to
Learn
• Balance
Equations
• Convert
moles to
mass
• What I
Learned.
• How to
balance an
equation.
• Use of
conversion
factors
Chapter 7.1
Describing Chemical
Reactions
• Is the following sentence
true or false. The new
substances formed as a
result of a chemical reaction
are called products.
Chapter 7.1
Describing Chemical Reactions
Chemical Equations
• Circle the letter of each correct
sentence.
• A. Carbon and oxygen react to form
carbon monoxide.
• B. Carbon and oxygen react to form
carbon dioxide.
• C. Carbon dioxide yields carbon and
oxygen.
• D. The reaction of carbon and oxygen
yields carbon dioxide.
Chapter 7.1
Describing Chemical Reactions
Chemical Equations
• Is the following true or false.
• The Law of Conservation of
Mass states that mass is
neither created or destroyed
in a chemical reaction.
Chapter 7.1
Describing Chemical Reactions
Chemical Equations
• Circle the letter of each correct sentence
• According to the equation
• C + 02  CO2
• How many carbon atoms react with 14
molecules of oxygen to form 14
molecules of carbon dioxide?
• A. 1 B. 7 C. 14 D. 28
Chapter 7.1
Describing Chemical Reactions
Chemical Equations
• In the reaction represented by
the equation
•C + 02  CO2
• the mass of the carbon dioxide
produced equals
•
Chapter 7.1
Describing Chemical Reactions
Balancing Chemical Equations
• Is the following sentence
true or false.
• A chemical equation must
be balanced in order to
show that mass is
conserved during a reaction.
Chapter 7.1
Describing Chemical Reactions
Balancing Chemical Equations
• Circle the letter
• of the name given to the
numbers that appear before
formulas in a chemical
equation.
• A. Subscripts
• B. Mass numbers
• C. Atomic numbers
• D. coefficients
Chapter 7.1
Describing Chemical Reactions
Balancing Chemical Equations
• Is the following sentence true or
false?
• Because the equation
• N2H4 + 02  N2 + H2O
• has two nitrogen atoms on each
side, the equation is balanced?
Chapter 7.1
Describing Chemical Reactions
Counting with Moles
• Chemists use a counting unit
called a ______ to measure
amounts of substances
because chemical reaction
often involve large numbers of
small particles.
Chapter 7.1
Describing Chemical Reactions
Counting with Moles
• Circle the letter of each correct
answer
• If one carbon atom has the an
atomic mass of 12.0 amu and one
oxygen atom has an atomic mass of
16.0 amu, what is the molar mass of
carbon dioxide (CO2)
• A. 28.0 amu B. 44.0 amu
• C. 28.0 g D. 44.0 g
Chapter 7.1
Describing Chemical Reactions
Counting with Moles
• Circle the letter of the correct answer
• To convert grams of carbon dioxide
to moles of carbon dioxide, you must
multiply by which conversion factor?
• A. 44.0 g CO2/1 mole CO2
• B. 1 mole CO2/44.0 g CO2
• C 28.0 g CO2 /1 mole CO2
• D. 1 mole CO2/ 28.0 g CO2
Chapter 7.1
Describing Chemical Reactions
Formation of Water
Equation
2H2
02
Amount
2 mol
1 mol
Molar Mass
2.0
g/mol
Mass
Moles x
Molar Mass
32.0
g/mole
2H2O
18.0
g/mol
36.0 g
Chapter 7.1
Describing Chemical Reactions
Chemical Calculations.
• Circle the letter of the correct
answer
• One mole of oxygen has a mass
of 32.0 grams. What is the mass
of four moles of oxygen?
• A. 128 grams B. 144 grams
• C. 128 amu D. 144 amu