Problem — Boyle's law

Problem

An ideal gas at constant temperature goes from volume $V_1 = 4{,}0$ L (with $p_1 = 1{,}5$ atm) to volume $V_2 = 2{,}5$ L. Find the final pressure.

Solution

At constant temperature Boyle’s law holds: $p_1 V_1 = p_2 V_2$ I find the final pressure: $p_2 = p_1 \frac{V_1}{V_2}$ $p_2 = 1{,}5 \cdot \frac{4{,}0}{2{,}5}$ $\ev{p_2 = 2{,}4\ \text{atm}}$ The volume decreases, so the pressure increases: the product $pV$ stays constant along the isotherm.

Links

Topics: Kinetic theory of gases Concepts: Ideal gas law · Pressure Skills: Reading graphs