# Chemistry - test- help

1. Oct 29, 2005

### jewilki1

a. the first ionization energy of aluminum is 578 kJ/mol. How much energy is required to ionize one atom of Al?
I put E= 578 kJ/mol . is this how to start?

b. Write out balanced chemical equation that represents the first ionization of aluminum (you must include the physical states)

c. Calculate the wavelength of a photon that has just enough energy to ionize a single atom of aluminum.

d. how many moles of photons with the wavelength you calculated in part c are required to ionize 1.15 moles of aluminum?

Can you help me set these up. I am studying for a test and we have not been over all of these yet? Thanks.

2. Oct 29, 2005

### mrjeffy321

the energy given is in terms of moles. You are trying to find the energy for a single atom. So how many atoms in a mole....

Remember, Aluminum like to ionize to +3.

Using the equation E = H * C / Lambda,
where E is the energy of a wave, H is planks constant, C is the speed of light in a vacuum, and Lamba is the wavelength of the wave, you can solve for the wavelength since you know Energy and H and C are constants.
H = 6.63 E-34 Js/photon
C =3.0 E8 m/s

I think 1 photon will ionize 1 atom assuming the photon is of the correct energy.