Daily Quiz: UPSC Prelims Marathon – October 6

Photochemical smog is the chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere, which leaves airborne particles and ground-level ozone. It may include the following:

• Aldehydes
• Nitrogen oxides, particularly nitric oxide and nitrogen dioxide
• Peroxyacyl nitrates
• Tropospheric ozone
• Volatile organic compounds

All of these harsh chemicals are usually highly reactive and oxidizing. Photochemical smog is therefore considered to be a problem of modern industrialization.  It is present in all modern cities, but it is more common in cities with sunny, warm, dry climates and a large number of motor vehicles like in Delhi.

All the statements are correct

• When coal is burnt (e.g. in coal fed power plants), two types of ash is produced. One that falls in the bottom of the boiler is called bottom ash. Another is made of fine particles that are driven out along with the flue gases. These fine particles are captured using the electrostatic precipitators or some other filtration equipments when the flue gases reach at Chimney of the plant. This is called Fly Ash
• All fly ash includes substantial amounts of silicon dioxide (SiO2), aluminium oxide (Al2O3) and calcium oxide (CaO).
• Fly Ash was once discarded as a waste but today, it is increasingly emerging as a major input material in several industries including cement, agriculture, construction, Paints etc.

Probable uses of fly ash:

• Concrete production, as a substitute material for Portland cement and sand
• Embankments and other structural fills (usually for road construction)
• Waste stabilization and solidification
• Cement clinkers production – (as a substitute material for clay)
• Mine reclamation
• Stabilization of soft soils
• Road sub-base construction
• As Aggregate substitute material (e.g. for brick production)
• Mineral filler in asphaltic concrete
• Agricultural uses: soil amendment, fertilizer, cattle feeders, soil stabilization in stock feed yards, and agricultural stakes
• Loose application on rivers to melt ice
• Loose application on roads and parking lots for ice control

• Refrigerators in the late 1800s and early 1900s used the toxic gases, ammonia (NH₃), methyl chloride (CH₃Cl), and sulfur dioxide (SO₂), as refrigerants. After a series of fatal accidents in the 1920s when methyl chloride leaked out of refrigerators, a search for a less toxic replacement begun as a collaborative effort of three American corporations- Frigidaire, General Motors, and Du Pont. CFCs were first synthesized in 1928 by Thomas Midgley, Jr. of General Motors, as safer chemicals for refrigerators used in large commercial appilications.
• CFCs are safe to use in most applications and are inert in the lower atmosphere, they do undergo significant reaction in the upper atmosphere or stratosphere.

Hot Winds

• Sirocco – Sahara Desert
• Leveche -Spain
• Khamsin -Egypt
• Harmattan -Sahara Desert
• Santa Ana – USA
• Zonda –  Argentina
• Brick fielder –Australia

Cold Winds

• Mistral – Spain and France
• Bora – Adriatic coast
• Pampero – Argentina
• Buran –  Siberia

Statement 1 is incorrect:

Kimberly Plateau lies in the northern part of Australia

Statement 2 and 3 is correct:

• This plateau is made of volcanic eruption.

Minerals like iron, gold, lead, zinc, silver and diamond are found here.

All the above statements are correct.