Function of glycol in motor gasoline Glycol added to petrol primarily acts as a/an ______ agent.
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AAnti-knocking
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BAnti-icing
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CAnti–gum forming
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DDewaxing
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EAntioxidant
Answer
Correct Answer: Anti-icing
Explanation
Introduction / Context:In cold climates, carburetor and intake system icing can disrupt fuel–air mixing. Certain additives mitigate icing by altering water phase behavior and vaporization characteristics.
Given Data / Assumptions:
- Additive is a glycol (e.g., ethylene or diethylene glycol derivatives).
Concept / Approach:Glycols act as anti-icing agents by depressing the freezing point of water and promoting dissolution of moisture that could otherwise crystallize as ice in carburetors or throttle bodies. They are not primary anti-knock agents (which include high-octane blending components), nor are they gum inhibitors or dewaxing agents.
Step-by-Step Solution:
Identify icing issue → water freezing in induction.Glycol → freeze point depression and water solubilization.Select “Anti-icing.”Verification / Alternative check:Historical winter gasoline formulations include anti-icing additives (alcohols/glycols) to prevent carburetor icing.
Why Other Options Are Wrong:
- Anti-knock relates to octane improvers.
- Anti-gum agents are antioxidants/detergents.
- Dewaxing pertains to middle distillates, not gasoline.
Common Pitfalls:Assuming one additive provides all functions; modern gasolines use additive packages with distinct components for each role.
Final Answer:Anti-icing