Free Gases MCQs with Answers
443 Gases MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Gas behaviour is explained through the kinetic molecular theory and the relationships among pressure, volume and temperature. Work includes STP, Boyle's and Charles's laws, absolute zero, the ideal gas equation, and the distinction between ideal and real gases, especially the effects of intermolecular forces and molecular volume.
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443 questions · page 6 of 23
- A. High temperature
- B. Low temperature
- C. High pressure
- D. B and C
Explanation: Real gases deviate most from ideal behaviour at low temperature and high pressure.
Correct answer: B and C102. A real gas obeying vander waals equation will resemble the ideal gas if_______________________?
- A. Both a and b are small
- B. Both a and b are large
- C. a is small and b is large
- D. a is large and b is small
Explanation: In the van der Waals equation, a represents intermolecular attraction and b represents the volume occupied by gas molecules.
Correct answer: Both a and b are small- A. n2a/v correct for the intermolecular forces.
- B. nb correct for the volume occupied by gas molecules.
- C. at high densities the equation reduces to the ideal gas law
- D. all of the above statements are correct.
Explanation: In the van der Waals equation, the pressure correction n2a/v2 accounts for intermolecular attraction and the volume correction nb accounts…
Correct answer: at high densities the equation reduces to the ideal gas law- A. SO3
- B. SO2
- C. C6H6
- D. C3H8
Explanation: At STP, 1 mol of gas occupies 22.4 dm3. The amount of gas is 8.4 dm3/22.4 dm3 mol-1 = 0.375 mol, so its molar mass is 24 g/0.375 mol = 64…
Correct answer: SO2- A. Pascal
- B. Torricelli
- C. Newton
- D. Huygen
Explanation: Evangelista Torricelli invented the mercury barometer by showing that atmospheric pressure could support a column of mercury.
Correct answer: Torricelli- A. 1 atm
- B. 760 Torr
- C. 76cm of Hg
- D. All of these
Explanation: Standard atmospheric pressure at sea level and 0 °C is 1 atm, which is equivalent to 760 torr and a 76 cm column of mercury.
Correct answer: All of these- A. 0.1526 atm
- B. 116 mm of Hg
- C. 116 torr
- D. 1 atm
Explanation: A partial pressure is only the pressure contributed by one gas, so oxygen cannot have a partial pressure of 1 atm in the lungs because…
Correct answer: 1 atm- A. 2.24 dm3
- B. 22.4 dm3
- C. 1.12 dm3
- D. 112 dm3
Explanation: The molar mass of N2 is 2 x 14 g mol^-1 = 28 g mol^-1, so 2.8 g represents 2.8 g / 28 g mol^-1 = 0.10 mol.
Correct answer: 2.24 dm3- A. 0.5
- B. 4
- C. 1
- D. 2
Explanation: The balanced chemical equation for the reaction is:Q(s) + O2(g) → QO2(g)According to the problem, 2 moles of O2(g) are used to produce 1…
Correct answer: 1- A. 0°C
- B. 4°C
- C. -273.16˚C
- D. -173.16 ˚C
Explanation: This point, with a temperature of -273.15 ˚C, is the theoretical point where the samples would have "zero volume".
Correct answer: -273.16˚C111. A graph between volume and temperature gives a straight line which cuts the temperature axis at:
- A. 0 oC
- B. 273 oC
- C. 546 oC
- D. -273 oC
Explanation: The graph of temperature with volume should be a straight line passing through the origin (0,0), given the temperature is measured in…
Correct answer: -273 oC- A. 500 mm of Hg
- B. 900 mm of Hg
- C. 1,100 mm of Hg
- D. 1,270 mm of Hg
Explanation: Since the temperature is constant, this follows Boyle's Law: P₁V₁ = P₂V₂. We have P₁ = 760 mmHg, V₁ = 500 cm³, and V₂ = 300 cm³.
Correct answer: 1,270 mm of Hg- A. Isobaric
- B. Adiabatic
- C. Isochoric
- D. Isothermal
Explanation: Pressure and volume are said to be inversely proportional only when the temperature is kept constant.
Correct answer: Isothermal- A. variable
- B. constant
- C. discreet
- D. decreasing
Explanation: According to Boyle's Law, 'for a fixed amount of gas at a constant temperature, the product of pressure and volume remains constant.'
Correct answer: constant- A. Both are independent of each other
- B. Indirect
- C. Direct
- D. Dynamic
Explanation: According to the Boyle's law, an increase in the pressure of an ideal gas causes a proportionate decrease in its volume.
Correct answer: Direct- A. 1 atm
- B. 3 atm
- C. 6 atm
- D. 9 atm
Explanation: Since the pressure of a gas is inversely proportional to volume based on "Boyle's Law", therefore if volume increases by a factor of…
Correct answer: 1 atm- A. Charles's law
- B. Boyle's Law
- C. Avogadro's law
- D. Pascal's law
Explanation: This is correct as according to Boyle's law " The volume of the given mass of a gas is inversely proportional to the pressure applied to…
Correct answer: Boyle's Law- A. Curved
- B. Straight line
- C. Zigzag
- D. None of these options are correct
Explanation: If a chart is plotted between 1/V on the x-axis and the pressure P on the y-axis then a straight line is acquired.
Correct answer: Straight line- A. Pressure
- B. Temperature
- C. Volume
- D. Density
Explanation: Boyle's Law is a basic law in chemistry describing the behavior of a gas held at a constant temperature.
Correct answer: Temperature- A. 5%
- B. 10%
- C. 5.26%
- D. 4.26%
Explanation: Solution of the question: P1 V1 = P2 V2 ....(eq1) V2 = 5% decrease in the original volume ∴ V2 = 95 / 100 V1 Put this in eqn 1: P1 V1 = P2…
Correct answer: 5.26%