Home
Class 11
CHEMISTRY
Calculate the wavelength of the radiatio...

Calculate the wavelength of the radiation that would cause photo dissociation of chlorine molecule if the `Cl-Cl` bond energy is `243kJ//mol`.

Text Solution

Verified by Experts

The correct Answer is:
`4.9xx10^(-7)m`
`(243)/(96.368)=(1240)/(lambda(nm))`
`lambda=(1240xx96.368)/(243)=491.75xx10^(-9)m~~4.9xx10^(-7)m`
Promotional Banner

Similar Questions

Explore conceptually related problems

The ionization energy of hydrogen atom in the ground state is 1312 kJ "mol"^(-1) . Calculate the wavelength of radiation emitted when the electron in hydrogen atom makes a transition from n = 2 state to n = 1 state (Planck’s constant, h = 6.626 xx 10^(-34) Js , velocity of light, c = 3 xx 10^8 m s^(-1) , Avogadro’s constant, N_A = 6.0237 xx 10^23 "mol"^(-1) ).

The stopping potential for the photo-electrons emitted from a metal surface of work-function 1.7 eV is 10.4 eV. Find the wavelength of the radiation used. Also identify the energy-levels in hydrogen atom which will emit this wavelength.

A point source is emitting 0.2 W of ultravio- let radiation at a wavelength of lambda = 2537 Å . This source is placed at a distance of 1.0 m from the cathode of a photoelectric cell. The cathode is made of potassium (Work function = 2.22 eV ) and has a surface area of 4 cm^(2) . (a) According to classical theory, what time of exposure to the radiation shall be required for a potassium atom to accumulate sufficient energy to eject a photoelectron. Assume that radius of each potassium atom is 2 Å and it absorbs all energy incident on it. (b) Photon flux is defined as number of light photons reaching the cathode in unit time. Calculate the photon flux. (c) Photo efficiency is defined as probability of a photon being successful in knocking out an electron from the metal surface. Calculate the saturation photocurrent in the cell assuming a photo efficiency of 0.1. (d) Find the cut – off potential difference for the cell.

A monochromatic point source radiating wavelength 6000Å with power 2 watt, an aperture A of diameter 0.1 m and a large screen SC are placed as shown in fig, A photoemissive detector D of surface area 0.5 cm^(2) is placed at the centre of the screen . The efficiency of the detector for the photoelectron generation per incident photon is 0.9 (a) Calculate the photon flux at the centre of the screen and the photo current in the detector. (b) If the concave lens L of focal length 0.6 m is inserted in the aperture as shown . find the new values of photon flux and photocurrent Assume a uniform average transmission of 80% from the lens . (c ) If the work function of the photoemissive surface is 1eV . calculate the values of the stopping potential in the two cases (within and with the lens in the aperture).

Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom .Calculate the ionisation energy of sodium in Kj mol^(-1)

A 100 W sodium lamp radiates energy uniformly in all directions .The lamp located at the centre of a large sphere the absorbs all the sodium light which is incident on it.The wavelength of the sodium light 589 nm.(a) what is the energy per photo assosciated with the sodium light? (b)At what rate are the photons delivered to the sphere.