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.
Last updated
443 questions · page 5 of 23
- A. Aug - Nov
- B. Sep - Nov
- C. Nov - Dec
- D. Dec - Jan
Explanation: The Antarctic ozone hole reaches its greatest seasonal depletion during the Southern Hemisphere spring, especially from September to…
Correct answer: Sep - Nov- A. Cl2
- B. O3
- C. ClO2
- D. both B & C
Explanation: Ozone and chlorine dioxide are effective water disinfectants and do not produce the chlorinated organic by-products associated with…
Correct answer: both B & C- A. Ammonia
- B. Dissolved oxygen
- C. Carbon dixide
- D. All
Explanation: Ammonia reacts with chlorine to form chloramines, which can be toxic and cause unpleasant odours and irritation.
Correct answer: Ammonia- A. 10
- B. 100
- C. 10000
- D. 100000
Explanation: A chlorine radical is regenerated in catalytic ozone-depletion cycles, allowing one radical to destroy approximately 100,000 ozone…
Correct answer: 100000- A. DO
- B. BOD
- C. COD
- D. all of the above
Explanation: Dissolved oxygen, biochemical oxygen demand and chemical oxygen demand each provide information about water quality: DO indicates…
Correct answer: all of the above- A. CO
- B. NO2
- C. both a & b
- D. none of the above
Explanation: Nitrogen dioxide contributes to acid rain by reacting with atmospheric water and oxygen to form nitric acid and related acids; sulphur…
Correct answer: NO2- A. SO3
- B. CO
- C. NO
- D. H2SO4
Explanation: Sulphuric acid is generally a secondary pollutant because it forms in the atmosphere when sulphur oxides are oxidised and react with…
Correct answer: H2SO4- A. dinitrogen oxide
- B. nitrogen dioxide
- C. chlorine gas
- D. chlorine dioxide
Explanation: Nitrogen dioxide absorbs visible light and gives photochemical smog its characteristic yellow-brown colour.
Correct answer: nitrogen dioxide- A. ozone
- B. carbonic acid
- C. sulphuric acid
- D. carbon dioxide
Explanation: Carbon dioxide is normally classified as a primary pollutant because it is released directly by respiration, combustion and other sources.
Correct answer: carbon dioxide- A. Nox
- B. NO2
- C. N2O3
- D. NO
Explanation: In bacterial nitrogen transformations, nitric oxide, NO, can be produced as an intermediate during reduction of nitrogen oxides.
Correct answer: NO- A. the amount of ozone layer is greater in the region close to the equator
- B. ozone acts as filter for UV radiations
- C. in the equatorial region it acts as pollutant
- D. CFCs play effective role in removing O3 in the stratosphere
Explanation: The ozone layer is generally thinner over the equator than at high latitudes, so the statement that its amount is greater near the equator…
Correct answer: the amount of ozone layer is greater in the region close to the equator- A. CFC
- B. CO2
- C. CO
- D. Oxides of nitrogen
Explanation: CFCs release chlorine radicals in the stratosphere when broken down by ultraviolet radiation, and these radicals catalytically destroy…
Correct answer: CFC- A. troposphere
- B. stratosphere
- C. mesosphere
- D. photosphere
Explanation: Most atmospheric ozone is concentrated in the stratosphere, roughly 15 to 35 km above Earth's surface.
Correct answer: stratosphere- A. sufficient NO
- B. sunlight
- C. less movement of air
- D. winds
Explanation: Smog formation is favoured by sunlight, nitrogen oxides and stagnant air, because pollutants remain concentrated and sunlight drives…
Correct answer: winds- A. High temperature and high pressure
- B. Low temperature and low pressure
- C. High temperature and low pressure
- D. Low temperature and high pressure
Explanation: At low temperature, intermolecular attractions become important, and at high pressure, gas molecules are forced close together so their…
Correct answer: Low temperature and high pressure- A. Clausius
- B. Boltzman
- C. Charles
- D. Vander waal
Explanation: Van der Waals introduced corrections for both intermolecular attraction and the finite volume of gas molecules, which explain deviations…
Correct answer: Vander waal- A. Critical temperature
- B. Standard temperature
- C. Absolute temperature
- D. Upper consulate temperature
Explanation: The critical temperature is the highest temperature at which a gas can be liquefied by applying pressure, or equivalently the highest…
Correct answer: Critical temperature- A. Separation of gases
- B. Expansion of gases
- C. Compression of gases
- D. Liquefaction of gases
Explanation: The Linde process liquefies gases by repeated compression, cooling and expansion, using the Joule-Thomson effect.
Correct answer: Liquefaction of gases- A. Intermolecular attraction and infinite volume
- B. Elastic collisions and finite volume
- C. Intermolecular attractions and finite volume
- D. Intermolecular attraction only
Explanation: Real gases deviate from ideal behaviour because their molecules attract one another and occupy finite volume.
Correct answer: Intermolecular attractions and finite volume- A. Size of molecule
- B. Shape of molecule
- C. Intermolecular attractions
- D. All of the above
Explanation: Critical temperature is the highest temperature at which a gas can be liquefied by pressure.
Correct answer: All of the above