Question

Difficulty: MediumDrawing Logical Conclusions

Read the following passage:

Sacrificial zinc anodes are mounted on the submerged steel hulls and bronze propellers of ocean-going vessels to prevent galvanic corrosion in seawater. Because zinc possesses a more negative electrochemical potential than steel or bronze, electrical current in the conductive saltwater flows preferentially from the zinc, causing it to oxidize and corrode while leaving the ship's primary structural metals intact. However, this protective reaction requires continuous electrical and physical contact between the zinc and the surrounding electrolyte. If an anode is thoroughly covered by marine biofouling organisms, electrical flow is blocked.

Based on this passage, it can be logically concluded that a vessel whose zinc anodes become heavily encrusted with marine growth will lose galvanic corrosion protection even if substantial unoxidized zinc remains.

Answer: Answer

Answer

True
The conclusion is logically valid because the passage establishes that galvanic protection requires active current flow between the zinc and the surrounding electrolyte. Since marine biofouling blocks this flow, galvanic protection ceases regardless of the quantity of unoxidized zinc metal still attached to the vessel.

Step-by-Step Solution

1
Identify the conditions necessary for sacrificial anodes to provide galvanic corrosion protection.
Protection requires an active electrochemical circuit where current flows from the zinc into the seawater electrolyte.
Understanding the operational mechanism establishes what conditions cause the system to fail.
2
Analyze how marine biofouling alters these required conditions according to the text.
Biofouling completely blocks the flow of electrical current between the anode and the surrounding water.
Determining the direct physical impact of surface contamination on the protective reaction.
3
Synthesize the premises to evaluate the status of the vessel's corrosion protection.
Because the electrical flow is blocked, the mere physical presence of unoxidized zinc cannot provide protection, confirming the conclusion is True.
Deducing the logical outcome from the stated constraints without relying on outside assumptions.

Key Concept

Drawing logical deductions from technical premises regarding system dependencies and operational constraints
Estimated Time:1m 0s
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