Environmental Chemistry Questions — JEE Chemistry

Q1

The maximum prescribed concentration of copper in drinking water is :

A 3 ppm

B 5 ppm

C 0.5 ppm

D 0.05 ppm

Correct Answer

Option A

Solution

Maximum prescribed concentration of Cu in drinking water is 3 ppm.

Q2

The presence of soluble fluoride ion upto 1 ppm concentration in drinking water, is :

A safe for teeth

B harmful to skin

C harmful for teeth

D harmful to bones

Correct Answer

Option A

Solution

Fluoride (F–) ion conc upto 1 ppm makes the enamel of teeth much harder by converting.

Q3

Water sample is called cleanest on the basis of which one of the BOD values given below :

A 11 ppm

B 15 ppm

C 3 ppm

D 21 ppm

Correct Answer

Option C

Solution

BOD is the biological oxygen demand.

Cleanest water sample will have BOD value equal to 3 ppm as clean water could have BOD value of less than 5 ppm whereas highly polluted water could have BOD value of 17 ppm or more.

Q4

Which among the following pairs has only herbicides?

A Aldrin and Dieldrin

B Sodium chlorate and Aldrin

C Sodium arsinate and Dieldrin

D Sodium chlorate and sodium arsinite

Correct Answer

Option D

Solution

Both sodium chlorate and sodium arsenate behave as herbicide.

Q5

The water quality of a pond was analyzed and its BOD was found to be 4. The pond has :

A Very clean water

B Highly polluted water

C Water has high amount of fluoride compounds

D Slightly polluted water

Correct Answer

Option A

Solution

A clean water would have BOD value less than 5 ppm.

Q6

Which of the following are the Green house gases? A. Water vapour B. Ozone C. I

_2

D. Molecular hydrogen Choose the most appropriate answer from the options given below :

A A and D only

B A and B only

C B and C only

D C and D only

Correct Answer

Option B

Solution

Green house gases are $\mathrm{CO}_2, \mathrm{CH}_4$ , water vapour, nitrous oxide, $\mathrm{CFC}_8$ and ozone.

Q7

Match with . .tg .tg Pollutant Source

List - I		List - II
(A)	Microorganisms	(I)	Strip mining
(B)	Plant nutrients	(II)	Domestic sewage
(C)	Toxic heavy metals	(III)	Chemical fertilizer
(D)	Sediment	(IV)	Chemical factory

A A-II, B-III, C-IV, D-I

B A-II, B-I, C-IV D-III

C A-I, B-IV, C-II, D-III

D A-I, B-IV, C-III, D-II

Correct Answer

Option A

Solution

Pollutant Source

\begin{array}{ll} \text{ Microorganisms } & \rightarrow \text{ Domestic sewage } \\ \text{ Plant nutrients } & \rightarrow \text{ Chemical fertilizers } \\ \text{ Toxic heavy metals } & \rightarrow \text{ Chemical factory } \\ \text{ Sediment } & \rightarrow \text{ Strip mining } \end{array}

Q8

Peroxyacetyl nitrate (PAN), an eye irritant is produced by :

A classical smog

B acid rain

C photochemical smog

D organic waste

Correct Answer

Option C

Solution

Photochemical smog produce chemicals such as formaldehyde, acrolein and peroxyacetyl nitrate(PAN).

Q9

The concentration of dissolved oxygen (DO) in cold water can go upto :

A 14 ppm

B 16 ppm

C 8 ppm

D 10 ppm

Correct Answer

Option D

Solution

In cold water, dissolved oxygen (DO) can reach a concentration upto 10 ppm.

Q10

On the surface of polar stratospheric clouds, hydrolysis of chlorine nitrite gives A and B while its reaction with its reaction with HCl produces B and C. A, B and C are, respectively :

A HOCl, HNO3, Cl2

B Cl2, HNO3, HOCl

C HClO2, HNO2, HOCl

D HOCl, HNO2, Cl2O

Correct Answer

Option A

Solution

On the surface of polar stratospheric clouds, hydrolysis of chlorine nitrate as

\mathrm{ClONO}_{2}+\mathrm{H}_{2} \mathrm{O} \longrightarrow \underset{\mathrm{A}}{\mathrm{HOCl}}+\underset{\mathrm{B}}{\mathrm{HNO}_{3}}

\mathrm{ClONO}_{2}+\mathrm{HCl} \longrightarrow \underset{\mathrm{C}}{\mathrm{Cl}_{2}}+\underset{\mathrm{H}}{\mathrm{HNO}_{3}}

Hence A, B and C are HOCl, HNO3 and Cl2 respectively.