Gas Laws · Paper 1 — Free Physics HL Practice Questions

A student plots a graph of pressure $P$ against absolute temperature $T$ for a fixed mass of an ideal gas at constant volume. The graph is a straight line that, when extended, passes through the origin. What is the value of $T$ when $P = 0$?

A student traps $20.0 \text{ cm}^3$ of air in a syringe at a pressure of $1.01 \times 10^5 \text{ Pa}$. She seals the tip and pushes the plunger until the volume is $15.0 \text{ cm}^3$. The temperature of the air remains constant. What is the pressure of the trapped air after compression?

A hot air balloon contains $500 \text{ m}^3$ of air at $15 \text{ °C}$. The air is heated to $65 \text{ °C}$ at constant pressure. What is the new volume of the air?

At a pressure of 50 atm and a temperature of 300 K, the measured volume of carbon dioxide gas in an industrial reactor is less than the volume predicted by the ideal gas law. What is the primary reason for this discrepancy?