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Difficulty: EasyNegative Detail Identification

A Flameless Ration Heater (FRH) is a water-activated chemical heater included in military operational rations. It uses a mixture of powdered magnesium, iron, and sodium chloride inside a durable plastic bag. When approximately two tablespoons of plain water are added to the bag, an exothermic oxidation-reduction reaction occurs rapidly between the water and magnesium. This chemical reaction generates enough heat to raise the temperature of an eight-ounce prepackaged meal by 100 degrees Fahrenheit in twelve minutes. The reaction produces non-toxic hydrogen gas as a byproduct, so heating must always be conducted in well-ventilated areas.

According to the passage, all of the following statements about the Flameless Ration Heater are true EXCEPT:

  1. A
    It utilizes a chemical mixture containing powdered magnesium and iron.
  2. It must be activated inside a completely sealed, airtight space.Answer
  3. C
    It releases hydrogen gas as a byproduct during the heating process.
  4. D
    It is capable of heating a prepackaged meal in twelve minutes.

Answer

The statement claiming that the heater must be activated inside a completely sealed, airtight space is NOT true based on the passage.
The passage specifies that 'heating must always be conducted in well-ventilated areas' due to the generation of hydrogen gas. The assertion that the device must be activated in a completely sealed, airtight space directly contradicts this explicit requirement.

Step-by-Step Solution

1
Identify the negative constraint in the stem
The word 'EXCEPT' indicates that the correct choice must be false, unstated, or contradicted by the passage.
Negative detail questions require identifying the single statement that is not supported by the factual text.
2
Cross-reference each option against the passage details
The text confirms the presence of magnesium and iron, the release of hydrogen gas, and the twelve-minute heating duration.
Eliminating facts directly stated in the stimulus isolates the contradicted or unmentioned claim.
3
Identify the contradicted statement
The passage directs that 'heating must always be conducted in well-ventilated areas,' which directly contradicts the claim of operating in a sealed, airtight space.
A statement that directly opposes explicit textual evidence represents the correct negative detail.

Key Concept

Negative Detail Identification
Estimated Time:45s
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Negative Detail Identification

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