Question

The value of delta for the [C_rF_6]^3- complex is 182 kJ/mol. Calculate the expected wavelength of the absorption corresponding to promotion of an electron from the lower-energy to the higher-energy of orbital set in this complex. (Remember to divide by Avogadro's number.) Should the complex absorb in the visible range?

Answer 1

Answer:  Yes the absorb in the visible range.

Explanation:

The relationship between wavelength and energy of the wave follows the equation:

$E=\frac{Nhc}{\lambda}$

where,

$E$ = energy of the wave  = 182 kJ/mol  = 182000 J/mol

N = avogadro's number =  $6.023\times 10^{23}$

h = plank constant = $6.6\times 10^{-34}Js^{-1}$

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

$\lambda$ = wavelength of the wave = ?

Putting all the values:

$182000=\frac{6.023\times 10^{23}\times 6.6\times 10^{-34}\times 3\times 10^8m/s}{\lambda}$

$\lambda=0.65\times 10^{-6}m=650nm$    $(1nm=10^{-9}m)$

The wavelength range for visible rays is 400 nm to 750 nm, thus the complex absorb in the visible range.