Ideal Gases · Paper 1 — Free Chemistry SL Practice Questions

A student investigates the relationship between pressure and volume of a fixed amount of nitrogen gas at constant temperature. A graph of pressure $P$ against $\dfrac{1}{V}$ produces a straight line passing through the origin. Which conclusion is consistent with this observation?

A weather balloon contains $0.50\ \text{mol}$ of helium gas at a pressure of $100\ \text{kPa}$ and a temperature of $300\ \text{K}$. The balloon rises to an altitude where the pressure is $50\ \text{kPa}$ and the temperature is $250\ \text{K}$. Assuming ideal gas behaviour, what is the volume of the balloon at this altitude?

A student investigates the relationship between pressure and temperature for a fixed mass of nitrogen gas at constant volume. Pressure $P$ is plotted against temperature $\theta$ in degrees Celsius, producing a straight line. The line is extrapolated until it intersects the horizontal axis. What does this intersection point represent?

A sealed syringe contains $50.0 \text{ cm}^3$ of dry air at $1.00 \times 10^5 \text{ Pa}$ and $300 \text{ K}$. The plunger is pushed in, compressing the air to $25.0 \text{ cm}^3$, and the temperature rises to $330 \text{ K}$. Assuming ideal gas behaviour, what is the new pressure of the air?