NTA Abhyas NEET2020ChemistryChemical KineticsPractice
What is the binding energy (in J/mol or kJ/mol) of an electron in a metal, whose threshold frequency for photon electron is 2.5 × 1 0 14 s - 1 ?
Options
- A99.38 kJ/mol
- B1.66 × 1 0 - 19 J/mol
- C2.75 × 1 0 - 43 J/mol
- D7.22 × 1 0 17 kJ/mol
Correct answer
A. 99.38 kJ/mol
Step-by-step solution
Binding energy of electron = h ν 0 = 6.6 × 1 0 - 34 k g m 2 s - 1 × 2.5 × 1 0 14 s - 1 = 16.5 × 1 0 - 20 J Binding energy of 1 mol e - = 16.5 × 1 0 - 20 J e - 1 × 6.023 × 1 0 23 1 m o l e - = 99.38 × 1 0 3 J/mol = 99.38 kJ/mol