Class 11 Chemistry - Chapter Chemical Bonding and Molecular Structure NCERT Solutions | Draw diagrams showing the formation of 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.

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.

List gases which are responsible for greenhouse effect.

For the following bond cleavages, use curved-arrows to show the electron flow and classify each as homolysis or heterolysis. Identify reactive intermediate produced as free radical, carbocation and carbanion.

Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.

(a) P_4(s) + OH ^– _(aq)  →  PH_3(g) + HPO^{2 –} _(aq)

(b) N₂H_4(l) + ClO^{3 –} _(aq)  →  NO_(g)  +  Cl^–_(g)

(c) Cl₂O_{7 (g)}  +  H₂O_2(aq)  →  ClO ^– _2(aq)   +  O_2(g)  +  H ⁺ _(aq)

Calculate the entropy change in surroundings when 1.00 mol of H₂O(l) is formed under standard conditions. Δ_fH⁰ = –286 kJ mol^–1.

For the reaction

2 A(g) + B(g) → 2D(g)

ΔU⁰ = –10.5 kJ and ΔS⁰ = –44.1 JK^–1.

Calculate ΔG⁰ for the reaction, and predict whether the reaction may occur spontaneously.

Which one of the following statements is incorrect in relation to ionization enthalpy?
(a) Ionization enthalpy increases for each successive electron.
(b) The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration.
(c) End of valence electrons is marked by a big jump in ionization enthalpy.
(d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.

Calculate the enthalpy change for the process

CCl₄(g) → C(g) + 4 Cl(g)

and calculate bond enthalpy of C – Cl in CCl₄(g).

Δ_vapH⁰(CCl₄) = 30.5 kJ mol^–1.

Δ_fH⁰ (CCl₄) = –135.5 kJ mol^–1.

Δ_aH⁰ (C) = 715.0 kJ mol^–1 , where Δ_aH⁰ is enthalpy of atomisation

Δ_aH⁰ (Cl₂) = 242 kJ mol^–1

Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous?

Complete the following chemical reactions.

(i) PbS_(s)  +  H₂O_2(aq)   → 

(ii)  MnO^-_4(aq)  +  H₂O_2(aq)   →

(iii)  CaO_(s)  +  H₂O_(g)  →

(iv) AlCl_3(g)   +   H₂O_(I)   →

(v) Ca₃N_2(s)   +  H₂O_(I)  →

Classify the above into (a) hydrolysis, (b) redox and (c) hydration reactions.