Embibe Experts Solutions for Chapter: Environmental Chemistry, Exercise 2: Level 2

When huge amount of sewage is dumped into a river, the BOD will:
 

The smog is essentially caused by the presence of :

Which of the following is not amongst the components of photochemical smog.

Choose the CORRECT option in the given following statements:

(I) Clean water contains $\mathrm{BOD}$ value more than $5 \mathrm{ppm}$

(II) The soluble ${\mathrm{F}}^{-}$ ion makes the enamel on teeth into much harder as it converts hydroxyapatite into much harder fluorapatite.

(III) When the $\mathrm{pH}$ of the rain water drops below $5.6$, it is called acid rain

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

How many of the following is/are the correct match.

(i) Photochemical smog:

${\mathrm{CF}}_2{\mathrm{Cl}}_2$ (common component )

(ii) Ozone layer: Protects from the Sun's radiation of wavelength $255 \mathrm{nm}$

(iii) Methemoglobinemia : Caused by the presence of greater than $50 \mathrm{ppm}$ of nitrate in drinking water

(iv) Ozone layer depletion:

${\mathrm{ClO}}^{·}\left(\mathrm{g}\right)+\mathrm{O}\left(\mathrm{g}\right)\to {\mathrm{Cl}}^{·}\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$ (one of the reaction involved)

(v) DDT: Biodegradable pollutant

(vi) Green house gas: Methane

Which of the following is not a green house gas?

Drinking water gets contaminated with lead when lead pipes are used for transportation of water. The prescribed upper limit concentration of lead in drinking water is about?