Question

What is an example of a frequency calculations practice problem?

Answer 1

Check the following practice.

Explanation:

The bond energy of fluorine (`F_2`) is 159 kJ/mol.

1. Determine the energy, in J, of a photon of light needed to break an F-F bond.
2. Determine the frequency of this photon, in `s^(-1)`.
3. Determine the wavelength of this photon in nanometers.

Q 1. To determine the energy in J of one photon, we will convert the kJ/mol to J, as follows:

`?E " in "J=(159cancel(kJ))/(1cancel(mol))xx(1000J)/(1cancel(kJ))xx(1cancel(mol))/(6.022xx10^(23)"photon")`

`E=2.64xx10^(-19)J`

Q 2. To find the frequency of this photon, we can use: `E=hcolor(red)(nu)`

`=>color(red)(nu)=E/h=(2.64xx10^(-19)cancel(J))/(6.626xx10^(-34)cancel(J)*s)=3.98xx10^(14)s^(-1)`

Q 3. The wavelength is then calculated by: `color(red)(nu)=c/(lambda)`

`=>lambda=c/nu=(2.998xx10^8m*cancel(s))/(3.98xx10^(14)cancel(s^(-1)))`

`=>lambda=7.52xx10^(-7)m=752nm`