Question

The absorption of light of frequency 1.16 × 1011 Hz is required for CO molecules to go from the lowest rotational energy level to the next highest rotational energy level. Determine the energy for this transition in kJ/mol. h = 6.626 × 10-34 J · s ?

Answer 1

I think that you can do this:
Use the Einstein's Relationship: `E=h*nu` where `nu` is the frequency (given as `1.16xx10^11 Hz` ).
`E=1.16xx10^11*6.626xx10^-34=7.686xx10^-23 J=7.686xx10^-26 kJ`.
One mole contains an Avogadro's Number `N_A=6.022xx10^23 mol^-1` of entities (in this case CO molecules each one requiring the above energy to change level);
so finally the energy per mole will be:
`E_(mol)=E*N_A=7.686xx10^-26*6.022xx10^23=4.628xx10^-2 (kJ)/(mol)`.