1. How many moles of photons does a laser with an intensity of 0.1 watt at 560 nm produce in 1 hour?

2. A certain photochemical reaction requires an excitation of 126 kJ/mol. What is a) the frequency of the light b) the wavelength of the light.

3. If the energy output of a laser is 68 milliWatts and the radiation is at a l = 320 nm, how many photon are emitted per sec?

4. What does a quantum yield >> 1 indicate about the mechanism of a reaction.

5. The quantum yield for the photolysis of acetone

(CH3)2CO => C2H6 + CO

at 300 nm is 0.2.

How long would you have to irradiate the sample to produce 1 g of CO? The light used is 300 nm radiation and is absorbed at a rate equivalent to 0.01 J of radiation/s?

6. The mechanism of the photochemical reaction

H2 + Cl2 = 2HCl

is

Cl2 + hn => 2 Cl (1)

Cl + H2 => HCl + H (2)

H + Cl2 => HCl + Cl (3)

Cl + Cl = Cl2 (4)

Assuming their is a steady state in H and Cl and that the quantum efficiency of the first step is one and the rate of photon absorption is I, show that the rate equation is of the form:

rate=d[HCl]/2dt = k2[H2] sqr(I[Cl2]/k4)