AC-HPAT CHEMISTRY 2025
ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
Why do metal orthodontic braces not corrode? - ANSWERS-Because orthodontic
wires are positioned close to the oral mucosa for lengthy periods, they should be
resistant to corrosion and prevent the release of ions in the oral cavity, and should
not cause allergic reactions. In other words, orthodontic wires must be
biocompatible with oral tissues.
QUESTION 2
Oxidation - ANSWERS-Oxidation is any chemical reaction that involves the
moving of electrons. ... When iron reacts with oxygen it forms a chemical called
rust because it has been oxidized (the iron has lost some electrons) and the oxygen
has been reduced (the oxygen has gained some electrons).
QUESTION 3
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, AC-HPAT CHEMISTRY 2025
Anode vs Cathode - ANSWERS-The anode of a device is the terminal where
current flows in from outside. The cathode of a device is the terminal where
current flows out. ... By current we mean the positive conventional current. Since
electrons are negatively charged, positive current flowing in is the same as
electrons flowing out.
QUESTION 4
Electrolyte - ANSWERS-An electrolyte is a substance that produces an electrically
conducting solution when dissolved in a polar solvent, such as water. The
dissolved electrolyte separates into cations and anions, which disperse uniformly
through the solvent.
QUESTION 5
Galvanic Corrosion - ANSWERS-Galvanic corrosion occurs when two different
metals are in contact in a corrosive environment: one of the metals experiences an
accelerated corrosion rate. The contacting metals form a bimetallic couple because
of their different affinities (or attraction) for electrons.
QUESTION 6
reduction - ANSWERS-Reduction is a chemical reaction that involves the gaining
of electrons by one of the atoms involved in the reaction between two chemicals.
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, AC-HPAT CHEMISTRY 2025
The term refers to the element that accepts electrons, as the oxidation state of the
element that gains electrons is lowered.
QUESTION 7
oxidation redox reaction - ANSWERS-An oxidation-reduction (redox) reaction is a
type of chemical reaction that involves a transfer of electrons between two species.
An oxidation-reduction reaction is any chemical reaction in which the oxidation
number of a molecule, atom, or ion change by gaining or losing an electron.
QUESTION 8
Parts of Galvanic Cells - ANSWERS-1. The anode is an electrode where oxidation
occurs.
2. The cathode is an electrode where reduction occurs.
3. A salt bridge is a chamber of electrolytes necessary to complete the circuit in a
voltaic cell.
4. The oxidation and reduction reactions are separated into compartments called
half-cells.
5. The external circuit is used to conduct the flow of electrons between the
electrodes of the voltaic cell and usually includes a load.
6. The load is the part of the circuit which utilizes the flow of electrons to perform
some function.
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ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
Why do metal orthodontic braces not corrode? - ANSWERS-Because orthodontic
wires are positioned close to the oral mucosa for lengthy periods, they should be
resistant to corrosion and prevent the release of ions in the oral cavity, and should
not cause allergic reactions. In other words, orthodontic wires must be
biocompatible with oral tissues.
QUESTION 2
Oxidation - ANSWERS-Oxidation is any chemical reaction that involves the
moving of electrons. ... When iron reacts with oxygen it forms a chemical called
rust because it has been oxidized (the iron has lost some electrons) and the oxygen
has been reduced (the oxygen has gained some electrons).
QUESTION 3
END OF
PAGE 1
, AC-HPAT CHEMISTRY 2025
Anode vs Cathode - ANSWERS-The anode of a device is the terminal where
current flows in from outside. The cathode of a device is the terminal where
current flows out. ... By current we mean the positive conventional current. Since
electrons are negatively charged, positive current flowing in is the same as
electrons flowing out.
QUESTION 4
Electrolyte - ANSWERS-An electrolyte is a substance that produces an electrically
conducting solution when dissolved in a polar solvent, such as water. The
dissolved electrolyte separates into cations and anions, which disperse uniformly
through the solvent.
QUESTION 5
Galvanic Corrosion - ANSWERS-Galvanic corrosion occurs when two different
metals are in contact in a corrosive environment: one of the metals experiences an
accelerated corrosion rate. The contacting metals form a bimetallic couple because
of their different affinities (or attraction) for electrons.
QUESTION 6
reduction - ANSWERS-Reduction is a chemical reaction that involves the gaining
of electrons by one of the atoms involved in the reaction between two chemicals.
END OF
PAGE 2
, AC-HPAT CHEMISTRY 2025
The term refers to the element that accepts electrons, as the oxidation state of the
element that gains electrons is lowered.
QUESTION 7
oxidation redox reaction - ANSWERS-An oxidation-reduction (redox) reaction is a
type of chemical reaction that involves a transfer of electrons between two species.
An oxidation-reduction reaction is any chemical reaction in which the oxidation
number of a molecule, atom, or ion change by gaining or losing an electron.
QUESTION 8
Parts of Galvanic Cells - ANSWERS-1. The anode is an electrode where oxidation
occurs.
2. The cathode is an electrode where reduction occurs.
3. A salt bridge is a chamber of electrolytes necessary to complete the circuit in a
voltaic cell.
4. The oxidation and reduction reactions are separated into compartments called
half-cells.
5. The external circuit is used to conduct the flow of electrons between the
electrodes of the voltaic cell and usually includes a load.
6. The load is the part of the circuit which utilizes the flow of electrons to perform
some function.
END OF
PAGE 3
