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Unformatted text preview: mpose as they absorb ultraviolet (UV) radiation, as shown
by the equation below. Ozone serves to block harmful ultraviolet radiation that comes from the Sun.
O3(g) æUV Æ O2(g) + O(g) A molecule of O3(g) absorbs a photon with a frequency of 1.00 × 1015 s−1.
(i) How much energy, in joules, does the O3(g) molecule absorb per photon? E = hν = 6.63 × 10−34 J s × 1.00 × 1015 s−1
= 6.63 × 10 −19 J per photon One point is earned
for the correct answer. (ii) The minimum energy needed to break an oxygen-oxygen bond in ozone is 387 kJ mol−1. Does a photon
with a frequency of 1.00 × 1015 s−1 have enough energy to break this bond? Support your answer with a
calculation. 6.63 × 10 −19 J 6.022 × 1023 photons 1 kJ
× 3 = 399 kJ mol −1
10 J 399 kJ mol−1 > 387 kJ mol−1, therefore the bond can be broken. One point is earned for
calculating the energy.
One point is earned for the
comparison of bond energies. © 2007 The College Board. All rights reserved.
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This note was uploaded on 10/01/2009 for the course OC 9876 taught by Professor Dq during the Spring '09 term at UC Merced.
- Spring '09