Class 11 Chemistry - Chapter Hydrocarbons NCERT Solutions | In the alkane H3C – CH2 – C(

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.

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?

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.

What do you mean by green chemistry? How will it help decrease environmental pollution?

The ionization constant of dimethylamine is 5.4 x 10^-4. Calculate its degree of ionization in its 0.02 M solution. What percentage of dimethylamine is ionized if the solution is also 0.1 M in NaOH?

Kp = 0.04 atm at 899 K for the equilibrium shown below. What is the equilibrium concentration of C₂H₆ when it is placed in a flask at 4.0 atm pressure and allowed to come to equilibrium?

C₂H₆ (g) ↔ C₂H₄ (g) + H₂ (g)

Consider the reactions:

(a) H₃PO_2(aq) + 4 AgNO_3(aq) + 2 H₂O_(l) → H₃PO_4(aq) + 4Ag_(s) + 4HNO_3(aq)

(b) H₃PO_2(aq) + 2CuSO_4(aq) + 2 H₂O_(l) → H₃PO_4(aq) + 2Cu_(s) + H₂SO_4(aq)

(c) C₆H₅CHO_(l) + 2 [Ag (NH₃)₂]⁺_(aq) + 3OH^-_(aq) → C₆H₅COO^-_(aq) + 2Ag_(s) + 4NH_3(aq) + 2 H₂O_(l)

(d) C₆H₅CHO_(l) + 2Cu²⁺_(aq) + 5OH^-_(aq) → No change observed.

What inference do you draw about the behaviour of Ag⁺and Cu²⁺from these reactions?

In the estimation of sulphur by Carius method, 0.468 g of an organic sulphur compound afforded 0.668 g of barium sulphate. Find out the percentage of sulphur in the given compound.

Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in C₂H₄ and C₂H₂ molecules.

(i) Calculate the number of electrons which will together weigh one gram.
(ii) Calculate the mass and charge of one mole of electrons.

In a reaction A + B2 → AB2 Identify the limiting reagent, if any, in the following reaction mixtures.

(i) 300 atoms of A + 200 molecules of B

(ii) 2 mol A + 3 mol B

(iii) 100 atoms of A + 100 molecules of B

(iv) 5 mol A + 2.5 mol B

(v) 2.5 mol A + 5 mol B

Write down the reactions involved during the formation of photochemical smog.

Calculate the volume occupied by 8.8 g of CO₂ at 31.1°C and 1 bar pressure.

R = 0.083 bar L K^–1 mol^–1.