23-Photochemistry - Photochemistry Introduction ENERGY Heat...

This preview shows page 1 - 10 out of 26 pages.

The preview shows page 8 - 10 out of 26 pages.
Photochemistry
IntroductionHeatElectricityElectromagneticirradiation (light)ENERGY
PhotochemistryChemical reactions accompanied with light.1.Action of lightchemical change(light induced reactions)2. Chemical reactionlight emission(chemiluminescence)
- Chemiluminescence:P4 (g)+ O2 (g)+H2O(g)® ® ®P4O10+ hngreen- Bioluminescence:- mushrooms- insects- fishesLuminescence:
Definitions and termsLight:electromagnetic field vibrationspreading in quanta(photons)Photon:the smallest amount of lightcarrying energy
Energy of photons (A. Einstein)E =clhnh=h = Planck’s constant (6.6 · 10-34Js)c = speed of light (3 · 108ms-1)l= wavelengthn= frequency
Einstein’s Equivalency PrincipleOne particleof a chemical substance can absorb onlyone photonfrom a light beam:DE = hnFor one mole:DE = NhnN = Avogadro’s number (6.02 · 1023)
Chemical bond energies:from 100 – 1000 kJ/molLight energies:604 kJ/mol302151200 nm400 nm800 nmULTRAVIOLETVISIBLEINFRAREDSo UV – and VIS region is expected to induce chemicalreactions.
Laws of Photochemistry1.

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 26 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
N/A
Tags
Chemistry, pH, Reaction, Photon, Light, Chemical reaction, Hn

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture