Question

The energy of light calculated using the formulas below tell you the energy per photon of light. If light has a wavelength of 645 m, what is the energy of this light expressed in kJ/mol? A beam of radiation has an energy of 2.06×10? kJ/mol. What is the wavelength of this light?

Answer 1

The energy of light with a wavelength of 645 m is 9.82518 × 10^-19 J. To convert the energy to kJ/mol, divide it by Avogadro's number.

Step-by-step explanation:

The energy of light can be calculated using the formula E = hc/λ, where E is the energy of the light, h is Planck's constant (6.626 × 10^-34 J · s), c is the speed of light in a vacuum (3.00 × 10^8 m/s), and λ is the wavelength of the light. To find the energy of light with a wavelength of 645 m, we can substitute the given values into the formula:

E = (6.626 × 10^-34 J · s)(3.00 × 10^8 m/s) / 645 m

E = 9.82518 × 10^-19 J

To convert the energy from joules to kilojoules per mole, we need to divide the energy by Avogadro's number (6.022 × 10^23). This gives us:

Energy in kJ/mol = (9.82518 × 10^-19 J) / (6.022 × 10^23)

Energy in kJ/mol = 1.63123 × 10^-42 kJ/mol