Class 11 Chemistry - Chapter Environmental Chemistry NCERT Solutions | What are the reactions involved for ozon

Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?

What are the harmful effects of photochemical smog and how can they be controlled?

Write down the reactions involved during the formation of photochemical smog.

Explain tropospheric pollution in 100 words.

What would have happened if the greenhouse gases were totally missing in the earth's atmosphere? Discuss.

Statues and monuments in India are affected by acid rain. How?

What do you mean by green chemistry? How will it help decrease environmental pollution?

What is smog? How is classical smog different from photochemical smog?

What do you mean by ozone hole? What are its consequences?

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.

How do you account for the formation of ethane during chlorination of methane?

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

What will be the minimum pressure required to compress 500 dm³ of air at 1 bar to 200 dm³ at 30°C?

What are the common physical and chemical features of alkali metals?

Calculate the molecular mass of the following:
(i) H₂O
(ii) CO₂
(iii) CH₄

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

What is the basic theme of organisation in the periodic table?

Explain the formation of a chemical bond.

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.

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?

Calculate the mass of sodium acetate (CH₃COONa) required to make 500 mL of 0.375 molar aqueous solution. Molar mass of sodium acetate is 82.0245 g mol^–1

Fluorine reacts with ice and results in the change:

H₂O_(s) + F_2(g) → HF_(g) + HOF_(g)

Justify that this reaction is a redox reaction.

Compare the structures of H₂O and H₂O₂.

In the organic compound CH₂ = CH – CH₂ – CH₂ – C ≡ CH, the pair of hydridised orbitals involved in the formation of: C₂ – C₃ bond is:

(a) sp – sp²

(b) sp – sp³

(c) sp² – sp³

(d) sp³ – sp³

How can saline hydrides remove traces of water from organic compounds?

What is the total number of sigma and pi bonds in the following molecules?

(a) C₂H₂ (b) C₂H₄

Explain the formation of H₂ molecule on the basis of valence bond theory.

The reaction of cyanamide, NH₂CN (s), with dioxygen was carried out in a bomb calorimeter, and ΔU was found to be –742.7 kJ mol^–1 at 298 K. Calculate enthalpy change for the reaction at 298 K.

NH₂CN(g) + 3/2 O₂(g)  →  N₂(g) + CO₂(g) + H₂O(l)

What happens when

(a) Borax is heated strongly,

(b) Boric acid is added to water,

(c) Aluminium is treated with dilute NaOH,

(d) BF₃ is reacted with ammonia?

Given the standard electrode potentials,

K⁺/K = -2.93V, Ag⁺/Ag = 0.80V,

Hg²⁺/ Hg = 0.79V

Mg²⁺/ Mg = -2.37V. Cr³⁺/ Cr = -0.74V

Arrange these metals in their increasing order of reducing power.