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Kinetic Energy and Moles

Posted: Sun Nov 11, 2018 10:26 pm
by Dustin Shin 2I
In Test 2, one of the questions given was to find the total kinetic energy in 5 mol of ejected electrons. I used the Ek = 1/2mV^2 to find the kinetic energy and using the given numbers, my answer came to 1.82 x 10^-24 J. However this answer was wrong. I am wondering if I was supposed to multiply my final answer by 5 because I vaguely remember the textbook stating something about how answers are given in energies per mol. So was I supposed to multiply by 5 or did I do something else wrong?

Re: Kinetic Energy and Moles

Posted: Sun Nov 11, 2018 10:31 pm
by Adriana_4H
Remember that in the equation E=hv, E is the energy of only one photon...in this case photons are equivalent to particles so you would have to find out how many particles are in 5 mol of the substance and multiply that by the answer you got....that way you calculated the amount of energy ejected by 5 mol of photons.

Hope this helps :)