Q161. Detrimental solid waste liberated by a thermal power station is
A. Red mud
B. Fly ash
C. Granulated Slag
D. Carbon black
Answer – B. Fly ash
Explanation- Fly ash is a detrimental solid waste that is released by thermal power stations. It is a fine, powdery residue generated from the combustion of pulverized coal and contains various pollutants, including heavy metals, which can have negative environmental impacts if not properly managed.
Q162. The bed of catalyst used for the conversion of automobile emissions to CO2 is made of
A. Pt (Platinum)
B. MnO2 (Manganese dioxide)
C. MoO (Molybdenum oxide)
D. V2O2 (Vanadium oxide)
Answer – A. Pt (Platinum)
Explanation-Platinum (Pt) is commonly used as a catalyst in the conversion of automobile emissions, such as harmful gases like carbon monoxide (CO) and nitrogen oxides (NOx), into carbon dioxide (CO2). The catalytic converter in vehicles often contains a bed of platinum catalysts to facilitate these chemical reactions.
Q163. An instrument used in industry for purifying air contaminated with dust and smoke:
A. Scrubber
B. Blower
C. Extractor
D. Electrostatic precipitator
Answer – D. Electrostatic precipitator
Explanation-An electrostatic precipitator is an instrument used in industry to remove dust and smoke particles from the air. It works by using high voltage to charge the particles, which are then attracted to oppositely charged plates or electrodes. This process effectively purifies the air by collecting and removing the contaminants.
Q164. CO level in burnt flue gas up to 150 ppm can be monitored by means of
A. Non-dispersive IR spectroscopy
B. UV-Vis spectroscopy
C. Atomic absorption spectroscopy analysis
D. Flame photometry
Answer – A. Non-dispersive IR spectroscopy
Explanation-Non-dispersive IR spectroscopy is a technique used to measure the concentration of carbon monoxide (CO) in gases. It utilizes the characteristic absorption of CO in the infrared region of the electromagnetic spectrum. This method is suitable for monitoring CO levels in burnt flue gas up to 150 parts per million (ppm).
Q165. The permissible limit of Arsenic in drinking water:
A. 5 ppm
B. 7.5 ppm
C. 10 ppm
D. 12.5 ppm
Answer – A. 5 ppm
Explanation-The permissible limit of arsenic in drinking water is 5 parts per million (ppm). Arsenic is a toxic element that can have harmful health effects when present in high concentrations in water. Therefore, it is important to keep the arsenic levels below the permissible limit for safe drinking water.
Q166. The most effective sewage treatment is conducted by
A. Cation-anion exchange method
B. Activated sludge method
C. Incineration technique
D. None of the above
Answer – B. Activated sludge method
Explanation-The most effective sewage treatment method is the activated sludge method. In this process, sewage is mixed with a culture of microorganisms in the presence of air. The microorganisms, known as activated sludge, consume the organic matter in the sewage, breaking it down into harmless byproducts. This method efficiently treats sewage and removes pollutants, making it a widely used technique.
Q167. Monitoring of SO2 gas is done by passing through
A. [HgCl4]-2 solution
B. K- pyrogallate solution
C. Fehlings’ solution
D. Ammoniacal Cuprous Chloride solution
Answer – A. [HgCl4]-2 solution
Explanation-Monitoring of sulfur dioxide (SO2) gas can be done by passing it through a solution of [HgCl4]-2 (mercuric tetrachloride). SO2 reacts with the [HgCl4]-2 solution to form a white precipitate of mercuric sulfite (HgSO3), which can be visually observed and measured. This method is commonly used for detecting and quantifying SO2 gas.
Q168. Desalination of water is performed by
A. Lime-soda method
B. Permutit method
C. Ion-exchange method
D. Reverse Osmosis
Answer – D. Reverse Osmosis
Explanation-Desalination of water, the process of removing salt and other impurities from seawater or brackish water, is commonly performed using the reverse osmosis method. Reverse osmosis involves applying pressure to force water molecules through a semi-permeable membrane, leaving behind dissolved salts and impurities. This method is widely used for producing fresh water from seawater or other saline sources.
Q169. The acidity of normal rainwater is due to
A. CO
B. NO
C. CO2
D. H2S
Answer – C. CO2
Explanation-The acidity of normal rainwater is primarily due to the presence of carbon dioxide (CO2) in the atmosphere. CO2 combines with water in the air to form carbonic acid (H2CO3), which contributes to the acidity of rainwater. Other gases, such as sulfur dioxide (SO2) and nitrogen oxides (NOx), can also contribute to the acidity of rainwater when they react with water to form sulfuric acid (H2SO2) and nitric acid (HNO3), respectively.
Q170. Historical monuments and temples are badly damaged due to the corrosive action of
A. SO2
B. CO2
C. NH3
D. C2H2
Answer – A. SO2
Explanation-The corrosive action on historical monuments and temples is primarily caused by sulfur dioxide (SO2), which is emitted by industrial activities, fossil fuel combustion, and volcanic eruptions. SO2 reacts with moisture in the air to form sulfuric acid, which can corrode and deteriorate the surfaces of buildings and monuments.
While carbon dioxide (CO2) is a greenhouse gas and contributes to climate change, it does not have a direct corrosive effect on historical monuments and temples.
Ammonia (NH3) and acetylene (C2H2) are not typically associated with the corrosive action that damages historical monuments and temples. However, they can have other negative effects on materials and human health in different contexts.
