- What is the significance of the constant R in the Ideal Gas Law?
A) It represents the molar mass of the gas.
B) It is the universal gas constant.
C) It is the temperature in Kelvin.
D) It is the pressure of the gas.
Answer: B) It is the universal gas constant.
Explanation: The constant R is the universal gas constant that relates pressure, volume, temperature, and the number of moles in the Ideal Gas Law.
- If two gases have the same volume and temperature, how do their pressures compare?
A) They must have the same pressure.
B) The gas with the higher molar mass will have higher pressure.
C) The gas with the lower molar mass will have higher pressure.
D) Their pressures cannot be determined.
Answer: A) They must have the same pressure.
Explanation: According to the Ideal Gas Law, if volume and temperature are the same, the pressures of the gases must also be equal, regardless of their identities.
- Which of the following describes a process where a gas expands against an external pressure?
A) Isothermal process
B) Adiabatic process
C) Isobaric process
D) Isometric process
Answer: B) Adiabatic process
Explanation: An adiabatic process involves gas expansion or compression without heat exchange with the surroundings.
- The behavior of real gases can deviate from ideal behavior primarily due to:
A) High temperatures
B) Low pressures
C) Intermolecular forces
D) Low molar mass
Answer: C) Intermolecular forces
Explanation: Deviations from ideal behavior occur because real gases have intermolecular forces that are not accounted for in the Ideal Gas Law.
- What happens to the volume of a gas if the number of moles is decreased while keeping pressure and temperature constant?
A) Volume increases
B) Volume decreases
C) Volume remains the same
D) Volume fluctuates
Answer: B) Volume decreases
Explanation: According to Avogadro’s Law, if the number of moles decreases, the volume must also decrease at constant temperature and pressure.
- If a gas mixture contains different gases, what does each gas contribute to the total pressure?
A) Total pressure is the sum of their volumes.
B) Total pressure is the sum of their partial pressures.
C) Total pressure is independent of the individual gases.
D) Total pressure is determined by the heaviest gas only.
Answer: B) Total pressure is the sum of their partial pressures.
Explanation: Dalton’s Law states that in a mixture of gases, each gas contributes to the total pressure according to its partial pressure.
- In a closed system, if the temperature of a gas is raised, what happens to the pressure if the volume is allowed to change?
A) Pressure decreases
B) Pressure remains constant
C) Pressure increases
D) Pressure fluctuates
Answer: C) Pressure increases
Explanation: According to the Ideal Gas Law, if temperature increases and volume is allowed to change, pressure will increase.
- Which of the following is a key characteristic of an ideal gas?
A) Gas particles have significant volume.
B) Gas particles experience strong intermolecular forces.
C) Gas particles collide elastically.
D) Gas particles are at absolute zero temperature.
Answer: C) Gas particles collide elastically.
Explanation: In an ideal gas, all collisions between gas particles and between particles and walls are elastic, meaning no kinetic energy is lost.
- The term “molar volume” is defined as:
A) The volume occupied by one mole of gas at STP.
B) The volume of gas in a closed container.
C) The volume of gas at high pressure.
D) The volume of a gas at low temperature.
Answer: A) The volume occupied by one mole of gas at STP.
Explanation: Molar volume is typically 22.4 L for one mole of an ideal gas at standard temperature and pressure (STP).
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