Class 11 Chemistry - Chapter Environmental Chemistry NCERT Solutions | Have you ever observed any water polluti

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 are the reactions involved for ozone layer depletion in the stratosphere?

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?

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?

Saline hydrides are known to react with water violently producing fire. Can CO₂, a well known fire extinguisher, be used in this case? Explain.

Write the atomic number of the element present in the third period and seventeenth group of the periodic table.

Which of the following carbocation is most stable ?

Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor.

For an isolated system, ΔU = 0, what will be ΔS?

Explain the reason for the fusion of an organic compound with metallic sodium for testing nitrogen, sulphur and halogens.

Use the periodic table to answer the following questions.
(a) Identify an element with five electrons in the outer subshell.
(b) Identify an element that would tend to lose two electrons.
(c) Identify an element that would tend to gain two electrons.
(d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature.

Considering the elements B, C, N, F, and Si, the correct order of their non-metallic character is:
(a) B > C > Si > N > F
b) Si > C > B > N > F
(c) F > N > C > B > Si
d) F > N > C > Si > B

Convert the following into basic units:

(i) 28.7 pm

(ii) 15.15 pm

(iii) 25365 mg

Which of the following reactions will get affected by increasing the pressure?

Also, mention whether change will cause the reaction to go into forward or backward direction.

(i) COCl₂ (g) ↔ CO (g) + Cl₂ (g)

(ii) CH₄ (g) + 2S₂ (g) ↔ CS₂ (g) + 2H₂S (g)

(iii) CO₂ (g) + C (s) ↔ 2CO (g)

(iv) 2H₂ (g) + CO (g) ↔ CH₃OH (g)

(v) CaCO₃ (s) ↔ CaO (s) + CO₂ (g)

(vi) 4 NH₃ (g) + 5O₂ (g) ↔ 4NO (g)  +  6H₂O(g)