Q 21 :    

Read the passage given below and answer the following questions from (i) to (v):

Frothing in Yamuna:

 

 

The primary reason behind the formation of the toxic foam is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households. Yamuna’s pollution level is so bad that parts of it have been labelled ‘dead’ as there is no oxygen in it for aquatic life to survive.

 

(i) Predict the pH value of the water of river Yamuna if the reason for froth is high content of detergents dissolved in it.

  • 10–11

     

  • 5–7

     

  • 2–5

     

  • 7

     

(1)

 



Q 22 :    

Read the passage given below and answer the following questions from (i) to (v):

Frothing in Yamuna:

 

 

The primary reason behind the formation of the toxic foam is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households. Yamuna’s pollution level is so bad that parts of it have been labelled ‘dead’ as there is no oxygen in it for aquatic life to survive.

 

(ii) Which of the following statements is correct for the water with detergents dissolved in it?

  • Low concentration of hydroxide ion (OH) and high concentration of hydronium ion (HO)

     

  • High concentration of hydroxide ion (OH) and low concentration of hydronium ion (HO)

     

  • High concentration of hydroxide ion (OH) as well as hydronium ion (HO)

     

  • Equal concentration of both hydroxide ion (OH) and hydronium ion (HO)

     

(2)

 



Q 23 :    

Read the passage given below and answer the following questions from (i) to (v):

Frothing in Yamuna:

 

 

The primary reason behind the formation of the toxic foam is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households. Yamuna’s pollution level is so bad that parts of it have been labelled ‘dead’ as there is no oxygen in it for aquatic life to survive.

 

 (iii) The table provides the pH value of four solutions P, Q, R and S:

Solution pH value
P 2
Q 9
R 5
S 11

 

Which of the following correctly represents the solutions in increasing order of their hydronium ion concentration?

  • P > Q > R > S

     

  • P > S > Q > R

     

  • S < Q < R < P

     

  • S < P < Q < R

     

(3)

 



Q 24 :    

Read the passage given below and answer the following questions from (i) to (v):

Frothing in Yamuna:

 

 

The primary reason behind the formation of the toxic foam is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households. Yamuna’s pollution level is so bad that parts of it have been labelled ‘dead’ as there is no oxygen in it for aquatic life to survive.

 

(iv) High content of phosphate ion in river Yamuna may lead to:

  • decreased level of dissolved oxygen and increased growth of algae.

     

  • decreased level of dissolved oxygen and no effect of growth of algae.

     

  • increased level of dissolved oxygen and increased growth of algae.

     

  • decreased level of dissolved oxygen and decreased growth of algae.

     

(1)

 



Q 25 :    

Read the passage given below and answer the following questions from (i) to (v):

Frothing in Yamuna:

 

 

The primary reason behind the formation of the toxic foam is high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households. Yamuna’s pollution level is so bad that parts of it have been labelled ‘dead’ as there is no oxygen in it for aquatic life to survive.

 

(v) If a sample of water containing detergents is provided to you, which of the following methods will you adopt to neutralise it?

  • Treating the water with baking soda.

     

  • Treating the water with vinegar.

     

  • Treating the water with caustic soda.

     

  • Treating the water with washing soda.

     

(2)

 



Q 26 :    

Read the passage given below and answer the following questions from (i) to (v):

The amount of ozone in the atmosphere has begun to drop sharply from 1980s. This decrease has been linked to synthetic chemicals. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze harmful chemicals production at 1986 levels.

 

(i) At what level of atmosphere ozone layer is found?

  • Troposphere

     

  • Stratosphere

     

  • Biosphere

     

  • Ionosphere

     

(2)

 



Q 27 :    

Read the passage given below and answer the following questions from (i) to (v):

The amount of ozone in the atmosphere has begun to drop sharply from 1980s. This decrease has been linked to synthetic chemicals. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze harmful chemicals production at 1986 levels.

 

(ii) At higher level of atmosphere radiations act upon oxygen molecule to form:

  • oxygen

     

  • ozone

     

  • carbon monoxide

     

  • all of these

     

(2)

 



Q 28 :    

Read the passage given below and answer the following questions from (i) to (v):

The amount of ozone in the atmosphere has begun to drop sharply from 1980s. This decrease has been linked to synthetic chemicals. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze harmful chemicals production at 1986 levels.

 

(iii) What is the major cause of ozone depletion?

  • Chlorofluorocarbons

     

  • Hydrochlorofluorocarbons

     

  • Carbon tetrachloride and methyl chloroform

     

  • All of the above

     

(4)

 



Q 29 :    

Read the passage given below and answer the following questions from (i) to (v):

The amount of ozone in the atmosphere has begun to drop sharply from 1980s. This decrease has been linked to synthetic chemicals. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze harmful chemicals production at 1986 levels.

 

(iv) Which of the following sources is responsible for the depletion of ozone layer?

  •  

  •  

  • All of the above

     

(4)

 



Q 30 :    

Read the passage given below and answer the following questions from (i) to (v):

The amount of ozone in the atmosphere has begun to drop sharply from 1980s. This decrease has been linked to synthetic chemicals. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze harmful chemicals production at 1986 levels.

 

(v) In which of the following countries Ozone hole has appeared?

  • Africa

     

  • North America

     

  • Japan

     

  • Antarctica

     

(4)