According to Boyle's Law, at constant temperature, what happens to pressure when volume is decreased?

According to Boyle's Law, at constant temperature, what happens to pressure when volume is decreased?

• A. Pressure decreases.
• B. Pressure remains constant.
• C. Pressure increases with no change in temperature.
• D. Pressure increases when volume decreases at constant temperature.

Answer: (D)

At constant temperature with a fixed amount of gas, the product P·V remains constant (Boyle’s law). This means pressure is inversely related to volume: as you decrease volume, pressure must rise to keep P·V the same. For example, halving the volume at the same temperature doubles the pressure, and reducing volume further increases pressure proportionally. So the statement that pressure increases when volume decreases at constant temperature correctly captures this inverse relationship. The other ideas—pressure decreasing, or staying constant, or changing temperature—don’t align with the isothermal, fixed-mass condition described by Boyle’s law.

At constant temperature with a fixed amount of gas, the product P·V remains constant (Boyle’s law). This means pressure is inversely related to volume: as you decrease volume, pressure must rise to keep P·V the same. For example, halving the volume at the same temperature doubles the pressure, and reducing volume further increases pressure proportionally. So the statement that pressure increases when volume decreases at constant temperature correctly captures this inverse relationship. The other ideas—pressure decreasing, or staying constant, or changing temperature—don’t align with the isothermal, fixed-mass condition described by Boyle’s law.