Class 11 Chemistry - Chapter Chemical Bonding and Molecular Structure NCERT Solutions | Use Lewis symbols to show electron trans

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.

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 are pesticides and herbicides? Explain giving examples.

The enthalpies of all elements in their standard states are:

(i) unity

(ii) zero

(iii) < 0

(iv) different for each element

How will you convert benzene into

(i) p - nitrobromobenzene

(ii) m - nitrochlorobenzene

(iii) p - nitrotoluene

(iv) acetophenone?

How do you expect the metallic hydrides to be useful for hydrogen storage? Explain.

Among NH₃, H₂O and HF, which would you expect to have highest magnitude of hydrogen bonding and why?

Nitric oxide reacts with Br₂ and gives nitrosyl bromide as per reaction given below:

2NO (g) + Br₂ (g) ↔ 2NOBr (g)

When 0.087 mol of NO and 0.0437 mol of Br₂ are mixed in a closed container at constant temperature, 0.0518 mol of NOBr is obtained at equilibrium. Calculate equilibrium amount of NO and Br₂ .

Convert the following into basic units:

(i) 28.7 pm

(ii) 15.15 pm

(iii) 25365 mg

The degree of ionization of a 0.1M bromoacetic acid solution is 0.132. Calculate the pH of the solution and the pK_a of bromoacetic acid.

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