Download Chapter 14 – Chemical Reactions

Chapter 14 NOTES – Chemical Reactions
Section 1 – Forming New Substances
Chemical Reaction – the process by which _________ or _____________ substances undergo
_____________ to _____________ one or more _____________ substances
•
The new substances have new _____________ and _____________ properties.
•
A chemical reaction is when _____________ bonds are _____________, atoms _____________
and _____________ chemical _____________ are _____________.
Clues to a chemical reaction:
Gas Formation – _______________________________________
Solid Formation – _______________________________________
Color Change – _______________________________________
Energy Change – _______________________________________
Chemical Formula – shorthand _____________ for a _____________ or a diatomic element using
chemical _____________ and _____________
A chemical _____________ shows the _____________ of _____________ present for each
_____________.
Writing Formulas for Covalent Compounds:
The names of covalent compounds use _____________ to tell you how many _____________ of each
_____________ are in the formula.
Prefixes Used In Chemical Names:
Example:
Carbon Dioxide
1
6
2
7
3
8
4
9
5
10
CO2
The lack of a _____________ on carbon means ______ carbon atom and the prefix ______ means
_______ oxygen atoms are present.
Writing Formulas for Ionic Compounds:
To write the formula for an ionic compound, you must make sure the compound’s overall charge is
_____________ (has __________________).
Example:
Magnesium chloride
MgCl2
Mg has a ______ charge and Cl has a ______ charge. In order to make a _____________ compound we
must use __________________________to neutralize the ________ charge of the Mg.
Chemical Equations – a shorthand _____________ of a chemical _____________ using chemical
_____________ and _____________
Example:
C
+
O2
Reactants

Yields
CO2
Products
Reactants – the _____________ materials of a chemical _____________
Products – the substances _____________ as a _____________ of a chemical _____________
Coefficient – a _____________ placed in _____________ of a chemical _____________ or
_____________
All chemical equations must be balanced.
Steps to Balancing Chemical Equations:
1. Count the atoms of each element in the reactants and in the products.
2. To balance the atoms, add in coefficients.
3. Make sure that there are equal numbers of each element on both sides of the equation.
Example:
HCl
+
Al
+

Na2S
Cl2

H2S
AlCl3
+
NaCl
Law of Conservation of Mass – mass is __________________________ nor _____________ in
ordinary chemical and physical changes
Developed by Antoine Lavoisier in the 1700’s
Section 14-3 Energy and Rates of Chemical Reactions
Exothermic Reaction – a chemical _____________ in which _____________ is _____________
Examples: fires, batteries
Endothermic Reaction – a chemical _____________ in which _____________ is _____________
Example: photosynthesis
Law of Conservation of Energy – states that _____________ is neither _____________ nor
_____________
Activation Energy – _____________ amount of _____________ needed for substances to
_____________
Factors that Affect Rates of Reaction:
Temperature
Concentration of the substance
Surface Area
Presence of a catalyst or inhibitor
Catalyst – a substance that _____________ up a _____________ without _____________ change to the
reaction
A catalyst will _____________ the activation energy, which allows the reaction to occur
_____________.
Examples: enzymes, platinum and palladium (in cars)
Inhibitor – _____________ down or _____________ a chemical reaction
Example: preservatives, poisons