POWER ENGINEERING 2A2 ACTUAL EXAM
PAPER 2026 QUESTIONS SOLUTIONS GRADED
A+
◉ What is electrochemistry? Answer: A process that involves the
flow of electrons plus chemical reactions between substances.
◉ What happens when a metal loses electrons? Answer: The metal
is weakened
◉ What is oxidation? Answer: the loss of one or more electrons
◉ What is reduction? Answer: The gain of electrons by a substance
at the expense of the metal. IE the metal corrodes.
◉ What is redox? Answer: Reduction and oxidation at the same time.
This is what happens during corrosion.
◉ Where does oxygen and hydrogen reduction occur? Answer: In
the substance that is reacting with the metal.
◉ Oxygen and Hydrogen Reduction
,- What can you say of the hydrogen content in acidic verses base
fluids? Answer: Acidic fluids have high hydrogen content (ions)
◉ Oxygen and Hydrogen Reduction
- How do acidic fluids corrode materials? Answer: The hydrogen
ions adsorb onto the metal then the electrons from the metal react
with the hydrogen ions which then causes loss of ions.
◉ Oxygen and Hydrogen Reduction
- How do neutral fluids corrode material? Answer: If there is air
dissolved in the fluid then the electrons in the metal react with the
oxygen in the fluid.
◉ What are the two types of corrosion electrodes? Answer: Anodes
and cathodes
◉ What are anodes? Answer: Electrodes that discharge electrons
◉ What are cathodes? Answer: Electrodes that receive electrons
◉ In electrochemistry, what is the electrode where the corrosion
occurs? Answer: Anode. Called an anodic reaction.
,◉ What is a corrosion cell? Answer: A corrosion cell combines all the
components necessary for corrosion.
◉ What are the parts of a corrosion cell? Answer: Cathode
Anode
Electrical connection
Electrolyte
◉ What are the two general environments when speaking of
corrosion? Answer: External - Natural Environment
Internal - Fluids involved in the process
◉ What are the three types of external environments? Answer: Soil,
air, water
◉ As an external environment, how could air be a concern for
corrosion? Answer: Acid rain from industrial pollution.
Salt water near the coast.
High humidity accelerates corrosion
Hi temperature accelerates corrosion
, ◉ As an external environment, how could water be a concern for
corrosion? (3 Things) Answer: If there are dissolved solids, dissolved
gasses, biological micro-organisms.
◉ As an external environment, how could soil be a concern for
corrosion? Answer: It could have high moisture content, oxygen
content, electrical conductivity, acidity, dissolved salts, anaerobic
bacteria.
◉ What is uniform corrosion? What is it caused by? Answer:
Corrosion over an entire surface or large section of a surface. It is a
general uniform thinning of the metal.
Caused by microscopic anode and cathode sites that continually
alternate.
◉ What is localized corrosion? What is it caused by? Answer:
Aggressive corrosive activity at a localized site.
Caused by the cathode being significantly larger than the anode.
◉ What is more dangerous and why? Uniform corrosion or localized
corrosion. Answer: Uniform corrosion is easy to monitor and
predict. Localized corrosion is most dangerous since only a small
amount of localized metal loss can cause a component failure.
PAPER 2026 QUESTIONS SOLUTIONS GRADED
A+
◉ What is electrochemistry? Answer: A process that involves the
flow of electrons plus chemical reactions between substances.
◉ What happens when a metal loses electrons? Answer: The metal
is weakened
◉ What is oxidation? Answer: the loss of one or more electrons
◉ What is reduction? Answer: The gain of electrons by a substance
at the expense of the metal. IE the metal corrodes.
◉ What is redox? Answer: Reduction and oxidation at the same time.
This is what happens during corrosion.
◉ Where does oxygen and hydrogen reduction occur? Answer: In
the substance that is reacting with the metal.
◉ Oxygen and Hydrogen Reduction
,- What can you say of the hydrogen content in acidic verses base
fluids? Answer: Acidic fluids have high hydrogen content (ions)
◉ Oxygen and Hydrogen Reduction
- How do acidic fluids corrode materials? Answer: The hydrogen
ions adsorb onto the metal then the electrons from the metal react
with the hydrogen ions which then causes loss of ions.
◉ Oxygen and Hydrogen Reduction
- How do neutral fluids corrode material? Answer: If there is air
dissolved in the fluid then the electrons in the metal react with the
oxygen in the fluid.
◉ What are the two types of corrosion electrodes? Answer: Anodes
and cathodes
◉ What are anodes? Answer: Electrodes that discharge electrons
◉ What are cathodes? Answer: Electrodes that receive electrons
◉ In electrochemistry, what is the electrode where the corrosion
occurs? Answer: Anode. Called an anodic reaction.
,◉ What is a corrosion cell? Answer: A corrosion cell combines all the
components necessary for corrosion.
◉ What are the parts of a corrosion cell? Answer: Cathode
Anode
Electrical connection
Electrolyte
◉ What are the two general environments when speaking of
corrosion? Answer: External - Natural Environment
Internal - Fluids involved in the process
◉ What are the three types of external environments? Answer: Soil,
air, water
◉ As an external environment, how could air be a concern for
corrosion? Answer: Acid rain from industrial pollution.
Salt water near the coast.
High humidity accelerates corrosion
Hi temperature accelerates corrosion
, ◉ As an external environment, how could water be a concern for
corrosion? (3 Things) Answer: If there are dissolved solids, dissolved
gasses, biological micro-organisms.
◉ As an external environment, how could soil be a concern for
corrosion? Answer: It could have high moisture content, oxygen
content, electrical conductivity, acidity, dissolved salts, anaerobic
bacteria.
◉ What is uniform corrosion? What is it caused by? Answer:
Corrosion over an entire surface or large section of a surface. It is a
general uniform thinning of the metal.
Caused by microscopic anode and cathode sites that continually
alternate.
◉ What is localized corrosion? What is it caused by? Answer:
Aggressive corrosive activity at a localized site.
Caused by the cathode being significantly larger than the anode.
◉ What is more dangerous and why? Uniform corrosion or localized
corrosion. Answer: Uniform corrosion is easy to monitor and
predict. Localized corrosion is most dangerous since only a small
amount of localized metal loss can cause a component failure.
