Question

long Answer Type Questions :
The wave number of a radiation is 500 cm. Find ou
(i) Wavelength
(ii) Frequency .
(iii) Time period
(iv) Energy in terms of joule per photon
(v) Energy in terms of kcal per mol of photon
Discuss photoelectric effect in detail.​

Answer 1

The correct question is:

The wave number of a radiation is 500 cm-1

Given:

The wave number of a radiation is 500 cm-1

To find:

Find out (i) Wavelength (ii) Frequency (iii) Time period

(iv) Energy in terms of joule per photon

(v) Energy in terms of kcal per mol of photon

Discuss photoelectric effect in detail.

Solution:

From given, we have,

Wave number  

v− = 500 cm-1 = 5 m-1

Wavelength

λ = 1/v− = 1/5 = 0.2 m

Wavelength in Angstrom

= 0.2 m × 10^{10} = 2^9 A°

Frequency

υ = c/λ = 3 × 10^{10}/0.2 = 1.5 × 10^{11} s^{-1}

Time period

1/υ = 1/1.5 × 10^{11}  = 6.66 × 10^{-12} s

Energy in terms of joule per photon

E = hυ = 6.626×10^{−34} × 1.5×10{11} = 9.939×10^{−23} J

Energy in terms of kcal per mol of photon (1 kcal = 4.18×10³ J )

= 9.939×10^{−23} J × 1/4.18×10³ = 2.36×10^{-26} kcal

The photoelectric effect is the process that involves the ejection or release of electrons or other free carriers from the surface of materials when light falls on them.

Answer 2

Answer:

wavelength=1/wavenumber

frequency=c/v

E=hv