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
- Q:-
Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?
- Q:-
What are the harmful effects of photochemical smog and how can they be controlled?
- Q:-
Write down the reactions involved during the formation of photochemical smog.
- Q:-
Explain tropospheric pollution in 100 words.
- Q:-
What are the reactions involved for ozone layer depletion in the stratosphere?
- Q:-
What would have happened if the greenhouse gases were totally missing in the earth's atmosphere? Discuss.
- Q:-
Statues and monuments in India are affected by acid rain. How?
- Q:-
What do you mean by green chemistry? How will it help decrease environmental pollution?
- Q:-
What is smog? How is classical smog different from photochemical smog?
- Q:-
What do you mean by ozone hole? What are its consequences?
Popular Questions of Class 11 Chemistry
- Q:-
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
- Q:-
What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
- Q:-
What are the common physical and chemical features of alkali metals?
- Q:-
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
- Q:-
Describe the usefulness of water in biosphere and biological systems.
- Q:-
Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is bent while that of CO2 is linear. Explain this on the basis of dipole moment.
- Q:-
Arrange the bonds in order of increasing ionic character in the molecules: LiF, K2O, N2, SO2 and ClF3.
- Q:-
What is the minimum volume of water required to dissolve 1g of calcium sulphate at 298 K? (For calcium sulphate, Ksp is 9.1 x 10-6).
- Q:-
(i) Calculate the total number of electrons present in one mole of methane.
(ii) Find
(a) the total number and
(b) the total mass of neutrons in 7 mg of 14C. (Assume that mass of a neutron = 1.675 × 10–27 kg).(iii) Find
(a) the total number and
(b) the total mass of protons in 34 mg of NH3 at STP.Will the answer change if the temperature and pressure are chang
- Q:-
Express the following in the scientific notation:
(i) 0.0048
(ii) 234,000
(iii) 8008
(iv) 500.0
(v) 6.0012 - Q:-
Find the oxidation state of sodium in Na2O2.
- Q:-
Calculate the entropy change in surroundings when 1.00 mol of H2O(l) is formed under standard conditions. ΔfH0 = –286 kJ mol–1.
- Q:-
Calculate the wavelength of an electron moving with a velocity of 2.05 × 107 ms–1.
- Q:-
In Ostwald's process for the manufacture of nitric acid, the first step involves the oxidation of ammonia gas by oxygen gas to give nitric oxide gas and steam. What is the maximum weight of nitric oxide that can be obtained starting only with 10.00 g. of ammonia and 20.00 g of oxygen?
- All Chapters Of Class 11 Chemistry
- All Subjects Of Class 11