Class 11 Chemistry - Chapter Hydrocarbons NCERT Solutions | How do you account for the formation of

Addition of HBr to propene yields 2-bromopropane, while in the presence of benzoyl peroxide, the same reaction yields 1-bromopropane. Explain and give mechanism.

An alkene 'A' on ozonolysis gives a mixture of ethanal and pentan-3-one. Write structure and IUPAC name of 'A'.

Write IUPAC names of the products obtained by the ozonolysis of the following compounds:

(i) Pent-2-ene

(ii) 3,4-Dimethyl-hept-3-ene

(iii) 2-Ethylbut-1-ene

(iv) 1-Phenylbut-1-ene

How would you convert the following compounds into benzene?

(i) Ethyne         (ii) Ethene          (iii) Hexane

Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

Arrange benzene, n-hexane and ethyne in decreasing order of acidic behaviour. Also give reason for this behaviour.

Explain why the following systems are not aromatic?

Why is Wurtz reaction not preferred for the preparation of alkanes containing odd number of carbon atoms? Illustrate your answer by taking one example.

Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E⁺

(a) Chlorobenzene, 2,4-dinitrochlorobenzene, p-nitrochlorobenzene

(b) Toluene, p-H₃C-C₆H₄-NO₂, p-O₂N-C₆H₄-NO₂.

What are the necessary conditions for any system to be aromatic?

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?

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

Why does boron trifluoride behave as a Lewis acid?

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

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

Explain the difference in properties of diamond and graphite on the basis of their structures.

Write the names of isotopes of hydrogen. What is the mass ratio of these isotopes?

Suggest a list of the substances where carbon can exhibit oxidation states from -4 to +4 and nitrogen from -3 to +5.

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

A sample of pure PCl5 was introduced into an evacuated vessel at 473 K. After equilibrium was attained, concentration of PCl5 was found to be 0.5 × 10^–1 mol L^–1. If value of Kc is 8.3 × 10^–3, what are the concentrations of PCl₃ and Cl₂ at equilibrium?

PCl₅ (g) ↔ PCl₃ (g) + Cl₂(g)

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.

Explain structures of diborane and boric acid.

Pressure of 1 g of an ideal gas A at 27 °C is found to be 2 bar. When 2 g of another ideal gas B is introduced in the same flask at same temperature the pressure becomes 3 bar. Find a relationship between their molecular masses.