Class 11 Chemistry - Chapter Chemical Bonding and Molecular Structure NCERT Solutions | Considering x-axis as the internuclear a

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?

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

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

BeCl₂, BCl₃, SiCl₄, AsF₅, H₂S, PH₃

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.

Neon gas is generally used in the sign boards. If it emits strongly at 616 nm, calculate

(a) the frequency of emission,

(b) distance traveled by this radiation in 30 s

(c) energy of quantum and

(d) number of quanta present if it produces 2 J of energy.

The ionization constant of acetic acid is 1.74 x 10^-5. Calculate the degree of dissociation of acetic acid in its 0.05 M solution. Calculate the concentration of acetate ion in the solution and its pH.

The first ionization constant of H₂S is 9.1 × 10^–8. Calculate the concentration of HS^– ion in its 0.1M solution. How will this concentration be affected if the solution is 0.1M in HCl also ? If the second dissociation constant of H₂S is 1.2 × 10^–13, calculate the concentration of S^2– under both conditions.

Nitrogen laser produces a radiation at a wavelength of 337.1 nm. If the number of photons emitted is 5.6 × 10²⁴, calculate the power of this laser.

The ionization constant of phenol is 1.0 × 10^–10. What is the concentration of phenolate ion in 0.05 M solution of phenol? What will be its degree of ionization if the solution is also 0.01M in sodium phenolate?

Arrange the following type of radiations in increasing order of frequency:

(a) radiation from microwave oven

(b) amber light from traffic signal

(c) radiation from FM radio

(d) cosmic rays from outer space and

(e) X-rays.

The reaction:

CH₃CH₂I + KOH(aq) → CH₃CH₂OH + KI

is classified as :

(a) electrophilic substitution

(b) nucleophilic substitution

(c) elimination

(d) addition

The ionization constant of HF, HCOOH and HCN at 298K are 6.8 × 10^–4,  1.8 × 10^–4  and  4.8 × 10^–9 respectively.

Calculate the ionization constants of the corresponding conjugate base.

An ion with mass number 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. Assign the symbol to this ion.

The best and latest technique for isolation, purification and separation of organic compounds is:

(a) Crystallisation

(b) Distillation

(c) Sublimation

(d) Chromatography