Question

Calculate the energy in KJ/mol for a radiation having a wavelength of 2500 Ao .

Answer 1

Answer:

Hope this help........

Answer 2

Answer:

478.874 KJ/mol

Explanation:

Given,

$\textrm{Wavelength},\lambda\ = 2500\ A^O$

                                  $=2500\times 10^{-10}\ m$

                                  $=2.5\times 10^{-7}\ m$

Energy of one photon is given by,

           $E\ =\ \dfrac{h.c}{\lambda}$

              where,

                          $h=\textrm{planck's\ constant}=\ 6.626176\times 10^{-34} J-S$

                          $\textrm{c= speed of light}\ =\ 3\times 10^{8}m/s$

  Hence, Energy,

                        $E=\ \dfrac{6.626176\times 10^{-34}\times 3\times 10^{8}}{2.5\times 10^{-7}}$

                         $=7.95\times 10^{-19} J$

                         $=7.95\times 10^{-22} KJ$

$\textrm{Since, one mole}\ =\ 6.022\times 10^{23}$

Hence, energy of one mole of radiation,

                    $E=7.95\times 10^{-22}\times 6.022\times 10^{23}\ KJ/mol$

                              =478.874 KJ/mol

Hence, the total energy in one mole of radiation of given wavelength is 478.874 KJ.