Class 11 Chemistry - Chapter Structure of Atom NCERT Solutions | If the photon of the wavelength 150 pm s

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.

A photon of wavelength 4 × 10^–7 m strikes on metal surface, the work function of the metal being 2.13 eV. Calculate

(i) the energy of the photon (eV),

(ii) the kinetic energy of the emission, and

(iii) the velocity of the photoelectron (1 eV= 1.6020 × 10^–19 J).

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?

In what ways lithium shows similarities to magnesium in its chemical behaviour?

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)

What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4 g of carbon dioxide contained in a 9 dm³ flask at 27 °C ?

What do you understand by the term “non-stoichiometric hydrides”? Do you expect this type of the hydrides to be formed by alkali metals? Justify your answer.

How much time would it take to distribute one Avogadro number of wheat grains, if 10¹⁰ grains are distributed each second?

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

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

The enthalpies of all elements in their standard states are:

(i) unity

(ii) zero

(iii) < 0

(iv) different for each element

For the process to occur under adiabatic conditions, the correct condition is:
(i) ΔT = 0
(ii) Δp = 0
(iii) q = 0
(iv) w = 0

Predict which of the following reaction will have appreciable concentration of reactants and products:

a) Cl₂ (g)  ↔  2Cl (g)                             Kc = 5 ×10^–39

b) Cl₂ (g) + 2NO (g)  ↔  2NOCl (g)         Kc = 3.7 × 10⁸

c) Cl₂ (g) + 2NO₂ (g)  ↔  2NO₂Cl (g)      Kc = 1.8