- A gas occupies a volume of 10 L at a pressure of 1 atm. If the volume is reduced to 5 L, what will the new pressure be at constant temperature?
A) 0.5 atm
B) 1 atm
C) 2 atm
D) 5 atm
Answer: C) 2 atm
Explanation: According to Boyle’s Law, if the volume is halved, the pressure will double, resulting in a new pressure of 2 atm.
- What is the standard temperature and pressure (STP) defined as?
A) 0°C and 1 atm
B) 25°C and 1 atm
C) 0°C and 0.5 atm
D) 25°C and 0.5 atm
Answer: A) 0°C and 1 atm
Explanation: Standard temperature and pressure (STP) is defined as 0°C (273.15 K) and 1 atm pressure, which is often used for calculations involving gases.
- Which gas law would you use to predict the change in volume of a gas when the temperature changes at constant pressure?
A) Boyle’s Law
B) Charles’s Law
C) Ideal Gas Law
D) Avogadro’s Law
Answer: B) Charles’s Law
Explanation: Charles’s Law describes the relationship between volume and temperature at constant pressure, allowing predictions of how volume changes with temperature.
- If a gas is compressed to half its original volume at constant temperature, what will happen to its pressure according to Boyle’s Law?
A) It will remain the same.
B) It will increase by a factor of four.
C) It will double.
D) It will decrease by half.
Answer: C) It will double.
Explanation: Boyle’s Law indicates that if the volume is halved, the pressure will double, given that temperature remains constant.
- Which of the following is a real gas law that applies under high pressure and low temperature conditions?
A) Ideal Gas Law
B) Van der Waals Equation
C) Avogadro’s Law
D) Charles’s Law
Answer: B) Van der Waals Equation
Explanation: The Van der Waals equation accounts for the volume of gas particles and intermolecular forces, providing a more accurate representation of gas behavior under conditions where real gases deviate from ideal gas behavior.
- What happens to the volume of a gas when the temperature is decreased while keeping the pressure constant?
A) It increases.
B) It decreases.
C) It remains constant.
D) It doubles.
Answer: B) It decreases.
Explanation: According to Charles’s Law, if the temperature decreases while pressure remains constant, the volume of the gas will also decrease.
- What is the primary reason gases have low densities compared to solids and liquids?
A) Gas particles are tightly packed.
B) Gas particles are far apart and have high kinetic energy.
C) Gas particles have no volume.
D) Gas particles do not move.
Answer: B) Gas particles are far apart and have high kinetic energy.
Explanation: Gases have low densities because their particles are spaced far apart and are in constant motion, resulting in a lower mass per unit volume compared to solids and liquids.
- According to Graham’s Law of Effusion, which of the following gases would effuse the fastest?
A) Oxygen (O₂)
B) Nitrogen (N₂)
C) Helium (He)
D) Carbon dioxide (CO₂)
Answer: C) Helium (He)
Explanation: Graham’s Law states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass. Helium, being the lightest of the gases listed, will effuse the fastest.
- What is the term for the pressure exerted by a vapor in equilibrium with its liquid?
A) Atmospheric pressure
B) Partial pressure
C) Vapor pressure
D) Total pressure
Answer: C) Vapor pressure
Explanation: Vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its liquid phase at a given temperature. It reflects the tendency of a substance to evaporate.
- In an ideal gas, which of the following properties is directly related to temperature?
A) Pressure
B) Volume
C) Kinetic energy
D) All of the above
Answer: D) All of the above
Explanation: In an ideal gas, the pressure, volume, and kinetic energy are all directly related to temperature. As temperature increases, pressure and volume can also increase, depending on the constraints of the system.
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