Question

if light has a wavelength of 725nm, what is the energy of this light expressed with the units of kj/mol

01 Question (1 point) G Se 1st attempt Part 1 (0.5 point) Jad See Periodic Table If light has a wavelength of 725 nm, what is the energy of this light expressed with units of kJ/mol? kJ/mol Part 2 (0.5 point) A beam of radiation has an enerrgy of 2.75x102 kJ/mol. What is the wavelength of this light? nm

Answer 1

The energy expression of Light is -

hxc XNA J mol-1 E =-

h is planck's constant

= 6.626 X 10-31 1 s

c is velocity of light

= 3 x 108 m

N_A is Avogadro number

= 6.023 x 1023

$\lambda$ is the wavelength of light...

Part A

E= 6.626 x 10-31 x 3 x 108 x 6.023 x 1023 - Imol-1 = 165.14 x 10'Jmol-1 725 x 10-9

[ANSWER]

:: E= 165.14 kJ mol-1

Part B

hxcXNA X=

:: = 6.626 X 10-34 x 3 x 108 x 6.023 x 1023 2.75 X 102 x 103 —m = 435.36 x 10-9 m

[ANSWER]

= 435.36 nm