Class 11 Chemistry - Chapter Structure of Atom NCERT Solutions | A 25 watt bulb emits monochromatic yello

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?

Propanal and pentan-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene?

A sample of HI_(g) is placed in flask at a pressure of 0.2 atm. At equilibrium the partial pressure of HI_(g) is 0.04 atm. What is K_p for the given equilibrium ?

2HI (g) ↔ H₂ (g) + I₂ (g)

Why is a solution of potassium hydroxide used to absorb carbon dioxide evolved during the estimation of carbon present in an organic compound?

Which of the two: OO₂NCH₂CH₂O-   or   CH₃CH₂O- is expected to be more stable and why?

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?

Explain why alkyl groups act as electron donors when attached to a π system.

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.

Do you expect the carbon hydrides of the type (C_nH_2n+2) to act as 'Lewis' acid or base? Justify your answer.

Write balanced equations for reactions between

(a) Na₂O₂and water

(b) KO₂ and water

(c) Na₂O and CO₂

What does atomic radius and ionic  radius really mean to you?