Gas Laws Boyles Charles Gay Lussacs - UNSOLVED PRACTICE SET
Chapter: States of Matter | Topic: Gas Laws Boyles Charles Gay Lussacs
GAS LAWS BOYLES CHARLES GAY LUSSACS - UNSOLVED PRACTICE SET
Topic: Gas Laws Boyles Charles Gay Lussacs
Multiple Choice Questions
Q1. Boyle's Law states that at constant temperature:
- V ∝ T
- V ∝ 1/P
- P ∝ T
- V ∝ P
Q2. According to Charles's Law, the volume of a gas at constant pressure:
- Decreases with increasing temperature
- Increases with increasing temperature
- Remains constant with temperature
- Is independent of the amount of gas
Q3. Gay-Lussac's Law relates:
- Volume and temperature at constant pressure
- Pressure and temperature at constant volume
- Volume and pressure at constant temperature
- Mass and volume at constant temperature
Q4. A balloon is taken from a warm room to a cold room. It shrinks because:
- The number of moles of gas decreases
- Charles's Law - volume decreases with decreasing temperature at constant pressure
- Boyle's Law - pressure increases
- The gas leaks out
Q5. If the pressure on a gas is doubled at constant temperature, its volume becomes:
- Double
- Half
- Four times
- Unchanged
Q6. The absolute zero of temperature is:
- 0°C
- –273.15°C
- 273.15°C
- –100°C
Short Answer Questions
Q7. State Boyle's Law mathematically. Draw a graph showing the variation of pressure with volume for a fixed amount of gas at constant temperature.
Q8. State Charles's Law. What is the significance of the temperature –273.15°C in relation to this law?
Q9. State Gay-Lussac's Law. A sealed container contains gas at 27°C and 2 atm pressure. What will be the pressure if the temperature is raised to 327°C? (Volume remains constant)
Q10. Explain why the pressure of a gas in a sealed container increases when heated, using kinetic molecular theory.
Q11. A student plots a graph of V vs T (in °C) for a gas at constant pressure. Will the graph pass through the origin? Explain. What happens if T is in Kelvin?
Q12. A gas occupies 2.0 L at 1.0 atm pressure. If the pressure is increased to 4.0 atm at constant temperature, what will be the new volume? Which law do you use?
Long Answer Questions
Q13. (a) State and explain Boyle's Law with the help of a graph. What is the shape of the P-V graph and the P vs 1/V graph?
(b) A balloon contains 2.0 L of helium at 1.0 atm. If the balloon is compressed to 0.5 L at constant temperature, calculate the new pressure.
(c) Explain why Boyle's Law is not obeyed at very high pressures or very low temperatures.
Q14. (a) State and explain Charles's Law. Derive the relationship V₁/T₁ = V₂/T₂.
(b) A gas occupies 500 mL at 27°C. What volume will it occupy at 77°C if the pressure remains constant?
(c) Draw graphs showing:
(i) V vs T (in °C) at constant pressure
(ii) V vs T (in K) at constant pressure
What is the significance of the point where the line in graph (ii) intersects the temperature axis?
Q15. (a) State and explain Gay-Lussac's Law. Derive the relationship P₁/T₁ = P₂/T₂.
(b) A sealed flask contains a gas at 300 K and 1.5 atm. The flask is heated to 600 K. Calculate the new pressure.
(c) A pressure cooker whistle releases steam when the pressure exceeds a certain limit. Explain how Gay-Lussac's Law is involved in the working of a pressure cooker.
Numerical / Application-Based Problems
Q16. Solve the following problems using the appropriate gas law:
(a) A gas occupies 4.0 L at 2.0 atm pressure. What volume will it occupy at 8.0 atm pressure if the temperature remains constant?
(b) A balloon has a volume of 3.0 L at 300 K. What will be its volume at 450 K if the pressure remains constant?
(c) A gas in a sealed container has a pressure of 2.5 atm at 300 K. What will be the pressure at 450 K if the volume remains constant?
(d) A gas occupies 2.0 L at 300 K and 1.0 atm. What will be its volume at 600 K and 2.0 atm?
Q17. A student performs an experiment to verify Boyle's Law using a syringe:
(a) Initially, the gas in the syringe occupies 20.0 mL at 1.0 atm pressure. The student compresses the gas to 5.0 mL. Calculate the new pressure.
(b) The student then plots a graph of P vs V and another of P vs 1/V. Describe the shape of each graph.
(c) If the student uses 0.5 moles of gas at 300 K, calculate the value of PV at each stage and verify that it remains constant.
(d) The student notices that at very high pressures, the product PV is slightly higher than expected. Explain why real gases deviate from Boyle's Law at high pressures.
Q18. In India, gas laws have many practical applications in daily life:
(a) During a hot summer day in Delhi, a car tyre is inflated to a pressure of 2.0 atm at 30°C. After driving for an hour, the tyre temperature rises to 60°C. Assuming the volume of the tyre remains constant, calculate the new pressure inside the tyre. Is this increase in pressure dangerous? Explain.
(b) A LPG cylinder contains gas at a pressure of 10 atm at 27°C. On a hot day, the temperature rises to 47°C. Calculate the new pressure in the cylinder. Why do LPG cylinders have safety valves?
(c) A hot air balloon works on the principle of Charles's Law. Explain why heating the air inside the balloon causes it to rise.
(d) A student fills a balloon with helium at sea level (1.0 atm, 27°C) where it has a volume of 2.0 L. The balloon is taken to a hill station where the pressure is 0.8 atm and the temperature is 7°C. Calculate the new volume of the balloon.