Which of the following is a sink for CO?

• Haemoglobin

• Micro-organisms present in the soil
  
  

• Oceans

• Oceans

Which oxide of nitrogen is not a common pollutant introduced into the atmosphere both due to natural and human activity?

• N₂O₅

• NO₂

• NO

• N₂O

Which of the following region is coldest?

• Stratosphere

• Troposphere

• Mesosphere

• Thermosphere

Which of the following statement(s) is not correct?

• Suspended particulate matter is an important pollutant released by diesel vehicles

• Soot particles (size < 5$\mathrm{\mu }$) cause fibrosis of the lung living

• H₂SO₄ particulates have size of 500- 1000 nm

• Photochemical smog is formed by oxides of sulphur, smoke and dust particles

Green chemistry means such reactions which

• produce colour during reactions

• reduce the use and production of hazardous chemicals

• are related to the depletion of ozone layer

• study the reactions in plants

166.

Which one of the following is present as an active ingredient in bleaching powder for bleaching action?

• Ca(OCl)₂

• CaO₂Cl

• CaCl₂

• CaOCl₂

Eutrophication of a lake means, it

• is low is nutrients

• is high in nutrients

• has a high temperature

• has excess amount of organic matter

Which one of the following is mainly responsible for depletion of ozone layer?

• Methane

• Carbon dioxide

• Water

• Chlorofluorocarbons

Photochemical smog is due to the presence of:

• Oxides of sulphur.

• Oxides of nitrogen.

• Oxides of carbon.

• Chlorofluoro carbons.

Which of the following is secondary pollutant?

• CO₂

• N₂O

• PAN

• SO₂