Difficulty: Medium
Correct Answer: Cannot say
Explanation:
Introduction / Context:
This verification of truth question asks you to evaluate a conclusion about the relative heaviness of three gases, based on given comparative statements. The gases are hydrogen, helium and oxygen. The conclusion states that oxygen is the heaviest of the three. We must judge whether this conclusion is true, false, probably false or something that cannot be determined from the information provided in the statements, focusing strictly on logical consequences rather than external scientific facts.
Given Data / Assumptions:
Concept / Approach:
The statements tell us that hydrogen is lighter than both helium and oxygen. This means hydrogen is the lightest of the three. However, nothing in the statements compares helium and oxygen to each other. Oxygen could be heavier than helium, equal in weight under some units, or even lighter, although the last is unlikely in real life. Logically speaking, when there is no direct or indirect information comparing two elements, we cannot conclude a specific ordering between them. Therefore, whether oxygen is the heaviest cannot be definitively said from the given statements alone.
Step-by-Step Solution:
Step 1: Interpret Statement 1: Hydrogen is lighter than helium. So helium is heavier than hydrogen.
Step 2: Interpret Statement 2: Hydrogen is lighter than oxygen. So oxygen is heavier than hydrogen.
Step 3: Combine the two statements. Both helium and oxygen are heavier than hydrogen, making hydrogen the lightest of the three.
Step 4: Note that there is no statement comparing helium and oxygen. We do not know if helium is heavier than oxygen or if oxygen is heavier than helium.
Step 5: The conclusion claims that oxygen is the heaviest of the three gases.
Step 6: To accept this conclusion, we would need evidence that oxygen is heavier than helium, but the statements provide no such evidence.
Step 7: Therefore, we cannot logically confirm or deny that oxygen is the heaviest solely from the given statements.
Step 8: The safest classification is that we cannot say whether the conclusion is true or false based only on the information provided.
Verification / Alternative check:
From real-world chemistry, we know that oxygen is indeed heavier than both hydrogen and helium when considering molar mass. However, reasoning questions of this type are designed to test logical inference, not recall of data tables. If we imagine a hypothetical world where helium and oxygen had unknown relative weights but hydrogen was lighter than both, the given statements would still be satisfied. In that scenario, the conclusion about oxygen being the heaviest might or might not be true. Since both possibilities are consistent with the statements, the conclusion cannot be decided on their basis alone.
Why Other Options Are Wrong:
Labeling the conclusion as True would incorrectly treat external knowledge or an assumption as if it were given in the premises.
Calling it False or Probably false suggests we know oxygen is not the heaviest, which again goes beyond the statements.
Common Pitfalls:
A typical pitfall is to rely on scientific memory and simply choose True, because oxygen has a higher molar mass. Another error is to assume that if something cannot be proven true, it must be false. In logic-based reasoning, inability to prove or disprove often leads to the neutral classification of cannot say. Always check whether the necessary comparison or link is actually present in the given information before accepting a conclusion about relative ordering or magnitude.
Final Answer:
From the given statements alone, we cannot say whether oxygen is the heaviest of the three gases.
Discussion & Comments