Class 11 Chemistry - Chapter Environmental Chemistry NCERT Solutions | What do you mean by ozone hole? What are
What do you mean by ozone hole? What are its consequences?
In Polar Regions, stratospheric clouds provide the surface for chlorine nitrate and hypochlorous acid, which react further to give molecular chlorine. Molecular chlorine and HOCl are photolysed to give chlorine-free radicals.
Hence, a chain reaction is initiated. The chlorine-free radical is continuously regenerated, thereby depleting the ozone layer. This phenomenon is known as the 'Ozone hole'.
Effects of depletion of ozone layer
The ozone layer protects the Earth from the harmful UV radiations of the sun. With the depletion of the layer, more radiation will enter the Earth's atmosphere. UV radiations are harmful because they causes the ageing of skin, cataract, skin cancer, and sunburns. They cause death of many phytoplanktons, which leads to decrease of fish productivity. Excess exposure may even cause mutation in plants.
Increase in UV radiations, decreases the moisture content of the soil and damages both plants and fibres.
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:-
A large number of fish are suddenly found floating dead on a lake. There is no evidence of toxic dumping but you find an abundance of phytoplankton. Suggest a reason for the fish kill.
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:-
Give reasons:
(i) Conc. HNO3 can be transported in aluminium container.
(ii) A mixture of dilute NaOH and aluminium pieces is used to open drain.
(iii) Graphite is used as lubricant.
(iv) Diamond is used as an abrasive.
(v) Aluminium alloys are used to make aircraft body.
(vi) Aluminium utensils should not be kept in water overnight.
(vii) Aluminium wire is used to make transmission cables.
- Q:-
Balance the following redox reactions by ion – electron method :
(a) MnO4 – (aq) + I – (aq) → MnO2 (s) + I2(s) (in basic medium)
(b) MnO4 – (aq) + SO2 (g) → Mn2+ (aq) + HSO4– (aq) (in acidic solution)
(c) H2O2 (aq) + Fe 2+ (aq) → Fe3+ (aq) + H2O (l) (in acidic solution)
(d) Cr2O7 2– + SO2(g) → Cr3+ (aq) + SO42– (aq) (in acidic solution)
- Q:-
The pH of 0.1M solution of cyanic acid (HCNO) is 2.34. Calculate the ionization constant of the acid and its degree of ionization in the solution.
- Q:-
Explain the principle of paper chromatography.
- Q:-
The reaction,
CO(g) + 3H2(g) ↔ CH4(g) + H2O(g)
is at equilibrium at 1300 K in a 1L flask. It also contain 0.30 mol of CO, 0.10 mol of H2 and 0.02 mol of H2O and an unknown amount of CH4 in the flask. Determine the concentration of CH4 in the mixture. The equilibrium constant, Kc for the reaction at the given temperature is 3.90.
- Q:-
Describe the effect of :
a) addition of H2
b) addition of CH3OH
c) removal of CO
d) removal of CH3OH on the equilibrium of the reaction: 2H2(g) + CO (g) ↔ CH3OH (g)
- Q:-
Calculate the amount of carbon dioxide that could be produced when
(i) 1 mole of carbon is burnt in air.
(ii) 1 mole of carbon is burnt in 16 g of dioxygen.
(iii) 2 moles of carbon are burnt in 16 g of dioxygen.
- Q:-
Which one of the following alkali metals gives hydrated salts?
(a) Li (b) Na (c) K (d) Cs
- Q:-
Suggest the name of a Lewis acid other than anhydrous aluminium chloride which can be used during ethylation of benzene.
- Q:-
(a) How many sub-shells are associated with n = 4?
(b) How many electrons will be present in the sub-shells having ms value of –1/2 for n = 4?
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