Boyle’s law – verifying the classical statement “The absolute pressure of a given mass of a perfect gas varies inversely as its volume when the temperature remains constant.” Is this the correct statement of Boyle’s law?
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AYes
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BNo
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CYes, but only below 0 °C
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DYes, but only for monatomic gases
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ENo; it is Charles’s law
Answer
Correct Answer: Yes
Explanation
Introduction / Context:Boyle’s law is one of the foundational gas laws, describing how pressure and volume relate during isothermal (constant-temperature) transformations of a fixed mass of ideal gas.
Given Data / Assumptions:
- Fixed amount of a perfect (ideal) gas.
- Temperature held constant.
- Quasi-equilibrium changes so the state equation applies continuously.
Concept / Approach:For an ideal gas, pV = mRT. Holding T and m constant makes the right-hand side constant, so pV = constant. Therefore p ∝ 1/V (inverse proportionality), which is exactly the statement given.
Step-by-Step Solution:Write ideal gas law: pV = mRT.Hold T constant and m fixed → pV = constant.Rearrange: p = constant / V → p varies inversely with V.Conclude: the statement given is the classical wording of Boyle’s law.
Verification / Alternative check:p–V isotherms for ideal gases are rectangular hyperbolas. Experimental data for many gases at modest pressures approximate this behaviour, validating Boyle’s law as a limiting relation.
Why Other Options Are Wrong:
- “No” and conditional variants contradict the ideal-gas model where the law holds regardless of gas type at low to moderate pressures.
- Referencing Charles’s law is incorrect; that pertains to V ∝ T at constant pressure.
Common Pitfalls:Using gauge pressure instead of absolute; gas laws require absolute pressure and temperature for correct proportionalities.
Final Answer:Yes