Class 11 Chemistry - Chapter Structure of Atom NCERT Solutions | A photon of wavelength 4 × 10&ndas

The mass of an electron is 9.1 × 10^–31 kg. If its K.E. is 3.0 × 10^–25 J, calculate its wavelength.

Calculate the wavelength of an electron moving with a velocity of 2.05 × 10⁷ ms^–1.

Using s, p, d notations, describe the orbital with the following quantum numbers.

(a) n = 1, l = 0;

(b) n = 3; l =1

(c) n = 4; l = 2;

(d) n = 4; l =3.

Which of the following are isoelectronic species i.e., those having the same number of electrons?

Na⁺, K⁺, Mg²⁺, Ca²⁺, S^2–, Ar

Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 × 10^–10 s.

How many electrons in an atom may have the following quantum numbers?

(a) n = 4,

(b) n = 3, l = 0

Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (ν) and wave number () of the yellow light.

Indicate the number of unpaired electrons in: (a) P, (b) Si, (c) Cr, (d) Fe and (e) Kr.

Calculate the wave number for the longest wavelength transition in the Balmer series of atomic hydrogen.

Find energy of each of the photons which

(i) correspond to light of frequency 3× 1015 Hz.

(ii) have wavelength of 0.50 Å.

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?

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.

Write down the products of ozonolysis of 1,2-dimethylbenzene (o-xylene). How does the result support Kekule structure for benzene?

Arrange the following

(i) CaH₂, BeH₂ and TiH₂ in order of increasing electrical conductance.

(ii) LiH, NaH and CsH in order of increasing ionic character.

(iii) H-H, D-D and F-F in order of increasing bond dissociation enthalpy.

(iv) NaH, MgH₂ and H₂O in order of increasing reducing property.

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

An alkene ‘A’ contains three C – C, eight C – H σ bonds and one C – C π bond. ‘A’ on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write IUPAC name of ‘A’.

Write chemical reactions to show the amphoteric nature of water.

Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.

What causes the temporary and permanent hardness of water?

Describe the bulk preparation of dihydrogen by electrolytic method. What is the role of an electrolyte in this process?

At 700 K, equilibrium constant for the reaction:

H2 (g) + I2 (g) ↔ 2HI (g)

is 54.8. If 0.5 mol L^–1 of HI(g) is present at equilibrium at 700 K, what are the concentration of H₂(g) and I₂(g) assuming that we initially started with HI(g) and allowed it to reach equilibrium at 700K?