CHM 1020 Exam #4 ACTUAL UPDATED QUESTIONS AND CORRECT ANSWERS
Chemical Reaction Process in which at least one new substance is produced as a result of chemical
change
Combination Chemical reaction in which a single product is produced from two (or more)
reactants
Decomposition Chemical reaction in which a single reactant is converted into two (or more)
simpler substances (elements or compounds)
Displacement or Single Replacement Chemical reaction in which an atom or molecule displaces an atom or group of
atoms from a compound
Exchange or Double Replacement Chemical reaction in which two substances exchange parts with one another and
form two different substances
Combustion Chemical reaction between a substance and oxygen (usually from air) that
proceeds with the evolution of heat and light (usually from a flame)
Oxidation-reduction (redox) Chemical reaction in which there is a transfer of electrons from one reactant to
another reactant
Nonoxidation-reduction (nonredox) Chemical reaction in which there is no transfer of electrons from one reactant to
another reactant
oxidation number -Positive or negative number that indicates how many electrons an atom has
gained, lost, or shared to become stable
-A number that represents the charge that an atom appears to have when the
electrons in each bond it is participating in are assigned to the more
electronegative of the two atoms involved in the bond
Oxidation A reactant loses one or more electrons
Reduction A reactant gains one or more electrons
oxidizing agent The electron acceptor in a redox reaction.
, reduction agent electron donor
OIL RIG oxidation is loss, reduction is gain
Molecular Collisions Reactant molecules, ions, or atoms must come in contact (collide) with one
another in order for any chemical change to occur
Activation Energy - Energy needed to get a reaction started
• Minimum combined kinetic energy that colliding reactant particles must possess
in order for their collision to result in a chemical reaction
Collision Orientation Reaction rates are sometimes very slow because reactant molecules must be
orientated in a certain way in order forcollisions to lead successfully to products
exothermic chemical reaction -one in which more energy is released through product bond formation than is
needed to break reactant bonds, so heat is released
-Occurs when the energy required to break bonds in the reactants is less than the
energy released by bond formation in the products
endothermic chemical reaction -One in which more energy is needed to break the reactant bonds than is
released when product bonds form, so heat is absorbed.
-A chemical reaction where energy is absorbed. The products temperature is
colder than the reactants.
-Occurs when the energy required to break bonds in the reactants is more than
the energy released by bond formation in the products
Chemical Reaction Rate The rate at which reactants are consumed or products produced in a given time
period in a chemical reaction
physical nature of reactants •When reactants are all in the same physical state:
-Reaction rate is generally faster between liquid-state reactants than between
solid-state reactants
-Reaction rate is fastest between gaseous-state reactants
Reactants Concentration An increase in the concentration of a reactant causes an increase in the rate of the
reaction
reaction temperature -Reaction rate increases as the temperature of the reactants increases
-The increased molecular speed causes more collisions to take place in a given
time
Catalyst -A substance that increases a chemical reaction rate without being consumed in
the chemical reaction
-Increases reaction rates by providing alternative reaction pathways that have
lower activation energies than the original, uncatalyzed pathway
Chemical Equilibrium -In a chemical reaction, the state in which the rate of the forward reaction equals
the rate of the reverse reaction, so that the relative concentrations of the
reactants and products do not change with time.
-The state in which forward and reverse chemical reactions occur simultaneously
at the same rate
Chemical Reaction Process in which at least one new substance is produced as a result of chemical
change
Combination Chemical reaction in which a single product is produced from two (or more)
reactants
Decomposition Chemical reaction in which a single reactant is converted into two (or more)
simpler substances (elements or compounds)
Displacement or Single Replacement Chemical reaction in which an atom or molecule displaces an atom or group of
atoms from a compound
Exchange or Double Replacement Chemical reaction in which two substances exchange parts with one another and
form two different substances
Combustion Chemical reaction between a substance and oxygen (usually from air) that
proceeds with the evolution of heat and light (usually from a flame)
Oxidation-reduction (redox) Chemical reaction in which there is a transfer of electrons from one reactant to
another reactant
Nonoxidation-reduction (nonredox) Chemical reaction in which there is no transfer of electrons from one reactant to
another reactant
oxidation number -Positive or negative number that indicates how many electrons an atom has
gained, lost, or shared to become stable
-A number that represents the charge that an atom appears to have when the
electrons in each bond it is participating in are assigned to the more
electronegative of the two atoms involved in the bond
Oxidation A reactant loses one or more electrons
Reduction A reactant gains one or more electrons
oxidizing agent The electron acceptor in a redox reaction.
, reduction agent electron donor
OIL RIG oxidation is loss, reduction is gain
Molecular Collisions Reactant molecules, ions, or atoms must come in contact (collide) with one
another in order for any chemical change to occur
Activation Energy - Energy needed to get a reaction started
• Minimum combined kinetic energy that colliding reactant particles must possess
in order for their collision to result in a chemical reaction
Collision Orientation Reaction rates are sometimes very slow because reactant molecules must be
orientated in a certain way in order forcollisions to lead successfully to products
exothermic chemical reaction -one in which more energy is released through product bond formation than is
needed to break reactant bonds, so heat is released
-Occurs when the energy required to break bonds in the reactants is less than the
energy released by bond formation in the products
endothermic chemical reaction -One in which more energy is needed to break the reactant bonds than is
released when product bonds form, so heat is absorbed.
-A chemical reaction where energy is absorbed. The products temperature is
colder than the reactants.
-Occurs when the energy required to break bonds in the reactants is more than
the energy released by bond formation in the products
Chemical Reaction Rate The rate at which reactants are consumed or products produced in a given time
period in a chemical reaction
physical nature of reactants •When reactants are all in the same physical state:
-Reaction rate is generally faster between liquid-state reactants than between
solid-state reactants
-Reaction rate is fastest between gaseous-state reactants
Reactants Concentration An increase in the concentration of a reactant causes an increase in the rate of the
reaction
reaction temperature -Reaction rate increases as the temperature of the reactants increases
-The increased molecular speed causes more collisions to take place in a given
time
Catalyst -A substance that increases a chemical reaction rate without being consumed in
the chemical reaction
-Increases reaction rates by providing alternative reaction pathways that have
lower activation energies than the original, uncatalyzed pathway
Chemical Equilibrium -In a chemical reaction, the state in which the rate of the forward reaction equals
the rate of the reverse reaction, so that the relative concentrations of the
reactants and products do not change with time.
-The state in which forward and reverse chemical reactions occur simultaneously
at the same rate
