Boyle's Law in Isothermal Expansion

Steps:

• Boyle's Law states that for a fixed mass of gas at constant temperature, pressure times volume is constant: P × initial volume = P1 × V1.
• This implies pressure is inversely proportional to volume: P1 / P = initial volume / V1.
• Rearranging gives V1 / initial volume = P / P1.
• Test each option against this law to find the mismatched statement.

Why A is correct:

• Pressure is measured in N/m² (pascals) per SI unit definitions, but volume is measured in m³; however, A addresses general units rather than the specific inverse relationship between V1 and P1 during expansion.

Why the others are wrong:

• B: Matches Boyle's Law exactly, as P × volume remains constant.
• C: Incorrectly states direct proportionality; law shows inverse proportionality.
• D: Correctly reflects V1 / initial volume = P / P1 from the law.

Final answer: A