Question

The quantum efficiency for the formation of ethene from di-n-propylketone (heptan-4-one) with 313 nm light is 0.21. How many molecules of ethene per second, and moles per second, are formed when the sample is irradiated with a 313 nm light operating at 50W at that wavelength, and under conditions such that all light is absorbed by the sample

Answer 1

1.66×10^15

Step-by-step explanation:

Energy= power×time

Power= 50W

Time= 1s

Energy= 50×1= 50J

Number of photons absorbed=Eλ/hc

E= energy of photon

λ= wavelength of photons

h= planks constant

c= speed of light

n= 50×313×10^-9/6.6×10^-34×3×10^8

n= 7.9×10^19

But quantum yield ( Ф)= number of reaction events/ number of photons absorbed

Hence:

Number of reaction events= 0.21 ×7.9×10^19= 1.66×10^15