00:01
To calculate the energy of the photons, we can use one of two equations dependent on whether or not we have frequency or wavelength.
00:09
For part a, we have frequency, so the energy is going to be equal to planck's constant, which is h6 .626 times 10 to the negative 34 joules seconds, multiplied by the frequency of 5 .90 times 10 to the 19, 1 over 6 .2.
00:33
Seconds and we get 3 .91 times 10 to the negative 14 joules per photon.
00:47
To get kilojoules per mole, we then need to multiply that by a thousand, one kilojoules, sorry, divide by a thousand, one kilojoules is 1 ,000 joules.
01:03
And then to get moles in the denominator, we multiply by avagadro's number.
01:08
One mole is 6 .022 times 10 to the 23rd.
01:17
So we get 2 .35 times 10 to the 7 kilojoules per mole.
01:30
And then for b, we also have a frequency...