.A value of -390 k] mol“1 is calculated, which is substantially
exothermic and therefore an increase in temperature should be
expected. In fact, an increase in temperature would be expected
even in reactions with chemiluminescent quantum yields close
to unity. To see why this is so, the energy available from each
reacting phenyl oxalate molecule can be compared with the
energy released by each photon emitted. Assuming that the
lightstick reaction enthalpy (-390 k] moi“) is a good estimate
for the energy available for light emission, one can calculate that
6.5 X 10-19] (0.65 a]) of energy is released for each phenyl