Class 11 Chemistry - Chapter Chemical Bonding and Molecular Structure NCERT Solutions | Explain with the help of suitable exampl

What is meant by the term bond order? Calculate the bond order of: N₂, O₂,O₂⁺,and O₂^-.

Use molecular orbital theory to explain why the Be2 molecule does not exist.

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

Compare the relative stability of the following species and indicate their magnetic properties:

O₂,O₂⁺,O₂^- (superoxide), O₂^2-(peroxide)

Describe the hybridisation in case of PCl₅. Why are the axial bonds longer as compared to equatorial bonds?

Which out of NH₃ and NF₃ has higher dipole moment and why?

Discuss the shape of the following molecules using the VSEPR model:

BeCl₂, BCl₃, SiCl₄, AsF₅, H₂S, PH₃

Explain why BeH₂ molecule has a zero dipole moment although the Be–H bonds are polar.

Write Lewis symbols for the following atoms and ions:

S and S2–; Al and Al3+; H and H–

Describe the change in hybridisation (if any) of the Al atom in the following reaction.

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?

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?

Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.

Calculate a) ΔG0 and b) the equilibrium constant for the formation of NO₂ from NO and O₂ at 298K

NO (g) + ½ O₂ (g) ↔ NO₂ (g)

where Δ_fG⁰ (NO₂) = 52.0 kJ/mol

Δ_fG⁰ (NO) = 87.0 kJ/mol

Δ_fG⁰ (O₂) = 0 kJ/mol

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

(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

What is the concentration of sugar (C₁₂H₂₂O₁₁) in mol L^–1 if its 20 g are dissolved in enough water to make a final volume up to 2 L?

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

How does atomic radius vary in a period and in a group? How do you explain the variation?

Dual behaviour of matter proposed by de Broglie led to the discovery of electron microscope often used for the highly magnified images of biological molecules and other type of material. If the velocity of the electron in this microscope is 1.6 × 10⁶ ms^–1, calculate de Broglie wavelength associated with this electron.

Would you expect the second electron gain enthalpy of O as positive, more negative or less negative than the first? Justify your answer.

Symbols can be written, whereas symbols  are not acceptable. Answer briefly.

The pH of a sample of vinegar is 3.76. Calculate the concentration of hydrogen ion in it.