# Chemistry

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Calculate the energy in kJ/mol of a mol of photons in the ultra-violet region of the electromagnetic spectrum that has a wavelength of 2.88 × 10-7 m. Express answer in scientific notation.

I got 4.16 * 10^8

but the correct answer is supposed to be 4.16 * 10^2.

• Chemistry -

You must have just punched in a wrong number.
E = (hc/wavelength)*6.02E23
E = (6.626E-34*3E8/2.88E-7)*6.02E23 in Joules.
Then divide by 1000 to convert to kJ and round to 3 places. I get 415.5 kJ which I would round to 416 kJ.

• Chemistry -

Oh okay. Yeah I did convert wrong. Thank you.

• Chemistry -

Why did you multiply by Avogadro's Number???

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