Ncert Solutions Chemistry Class 11th

Wavelength, λ = (3 × 10⁸ ms^-1) / (5 × 10⁹ s^-1) = 6.0 x 10^-2 m

Frequency, ν = 1 / 2.0 × 10^-10 s = 5.0 x 10⁹ s^-1

Wavenumber, (? ) = 1 / (6.0 x 10^-2 m) = 16.66 m^-1

(i) Energy of photon (E) = hν, where h= Plank’s const, ν= Frequency

h= 6.626 × 10^-34 J s ; ν = 3 × 10¹⁵ Hz = 3 × 10¹⁵ s^-1

∴ E = (6.626 × 10^-34 J s) × (3 × 10¹⁵ s^-1) = 1.986 × 10¹⁸ J

(ii) Energy of photon (E) = hν = hc/λ, where λ= wavelength

h = 6.626 × 10^-34 J s ; c

Kindly go through the solution.

Kindly go through the solution 

(i) One mole of methane (CH₄) has = 6.022 × 10²³ molecules
     No. of electrons present in one molecule of CH₄ = 6 + (4 x 1) = 10
     No. of electrons present in 6.022 × 10²³ molecules of CH₄ = 6.022 × 10²³ × 10
     = 6.

43. A process which can take place of its own or initiate under some conditions. For example: Common salt dissolves in water of its own.

42. ?G = ?H – T?S

Where ?G = free energy change.

?H = enthalpy change.

?S = entropy change.

(i) Mass of an electron = 9.10939×10⁻³¹ kg = 9.1 × 10^-28 g
    ⇒ No. of electrons in 9.1 × 10^-28 g = 1 electron

    Therefore, No. of electrons in 1 g = 1/9.1 × 10^-28 = 1.098×10²⁷

(ii) One mole of electrons = 6.022 × 10²³ electrons