Class 11 Chemistry - Chapter Environmental Chemistry NCERT Solutions | What are the major causes of water pollu
What are the major causes of water pollution? Explain.
Water pollution arises as a result of several human activities, which leads to the presence of several undesirable substances in water. Major water pollutants with their sources have been tabulated as follows:
| Pollutant | Source |
| Radioactive substances | Mining of uranium-containing minerals |
| Heat | Water used for cooling in industries |
|
Plant nutrients
|
Chemical fertilizers |
| Toxic heavy metals | Chemical factories and industries |
| Sediments | Strip mining and soil erosion |
| Pesticides | Chemicals used for killing fungi, weed, insects |
|
Micro-organisms |
Domestic sewage |
| Organic wastes | Domestic sewage, decaying animals and plants, animal excreta and waste, discharge from food processing industries |
Roles played by major pollutants are:
1. Pathogens: These water pollutants include bacteria and other organisms. They enter water from animal excreta and domestic sewage. Bacteria present in human excreta (for example, Escherichia coli and Streptococcus faecalis) cause gastrointestinal diseases.
2. Organic wastes: These are biodegradable wastes that pollute water as a result of run off. The presence of excess organic wastes in water decreases the amount of oxygen held by water. This decrease in the amount of dissolved oxygen inhibits aquatic life.
3. Chemical pollutants: These are water soluble chemicals like heavy metals such as cadmium, mercury, nickel, etc. The presence of these chemicals (above the tolerance limit) can damage the kidneys, central nervous system, and liver.
More Questions From Class 11 Chemistry - Chapter Environmental Chemistry
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Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?
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What are the harmful effects of photochemical smog and how can they be controlled?
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Write down the reactions involved during the formation of photochemical smog.
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What are the reactions involved for ozone layer depletion in the stratosphere?
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Explain tropospheric pollution in 100 words.
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What would have happened if the greenhouse gases were totally missing in the earth's atmosphere? Discuss.
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Statues and monuments in India are affected by acid rain. How?
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What is smog? How is classical smog different from photochemical smog?
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What do you mean by ozone hole? What are its consequences?
Popular Questions of Class 11 Chemistry
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How do you account for the formation of ethane during chlorination of methane?
- Q:-
What are hybridisation states of each carbon atom in the following compounds ?
(i) CH2=C=O,
(ii) CH3CH=CH2,
(iii) (CH3)2CO,
(iv) CH2=CHCN,
(v) C6H6
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What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
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What are the common physical and chemical features of alkali metals?
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Calculate the molecular mass of the following:
(i) H2O
(ii) CO2
(iii) CH4 - Q:-
Assign oxidation number to the underlined elements in each of the following species:
(a) NaH2PO4
(b) NaHSO4
(c) H4P2O7
(d) K2MnO4
(e) CaO2
(f) NaBH4
(g) H2S2O7
(h) KAl(SO4)2.12 H2O
- Q:-
What is the basic theme of organisation in the periodic table?
- Q:-
Explain the formation of a chemical bond.
- Q:-
Choose the correct answer. A thermodynamic state function is a quantity
(i) used to determine heat changes
(ii) whose value is independent of path
(iii) used to determine pressure volume work
(iv) whose value depends on temperature only. - Q:-
A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased.
a) What is the initial effect of the change on vapour pressure?
b) How do rates of evaporation and condensation change initially?
c) What happens when equilibrium is restored finally and what will be the final vapour pressure?
Recently Viewed Questions of Class 11 Chemistry
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The species: H2O, HCO–3, HSO-4 and NH3 can act both as Brönsted acids and bases. For each case give the corresponding conjugate acid and base.
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What is the basic difference between the terms electron gain enthalpy and electronegativity?
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Consider the compounds, BCl3 and CCl4. How will they behave with water? Justify.
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What are hybridisation states of each carbon atom in the following compounds ?
(i) CH2=C=O,
(ii) CH3CH=CH2,
(iii) (CH3)2CO,
(iv) CH2=CHCN,
(v) C6H6
- Q:-
Write the formulae for the following compounds:
(a) Mercury(II) chloride
(b) Nickel(II) sulphate
(c) Tin(IV) oxide
(d) Thallium(I) sulphate
(e) Iron(III) sulphate
(f) Chromium(III) oxide - Q:-
What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
- Q:-
A reaction, A + B → C + D + q is found to have a positive entropy change. The reaction will be
(i) possible at high temperature
(ii) possible only at low temperature
(iii) not possible at any temperature
(iv) possible at any temperature
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How can the production of dihydrogen, obtained from ‘coal gasification’, be increased?
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The pH of 0.005M codeine (C18H21NO3) solution is 9.95. Calculate its ionization constant and pKb.
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Which one of the following will have largest number of atoms?
(i) 1 g Au (s)
(ii) 1 g Na (s)
(iii) 1 g Li (s)
(iv) 1 g of Cl2(g)
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