Braggs law to work out interplanar spacing d

[strugglin]

hi, I've been bashing my head against the wall for the past few days trying to work this one out!
ive worked out a de broglie wavelength of electrons accelerated from rest by a voltage of 100v to be around (1.23 x 10 ^-10) m.
now using a KCl diffraction , these electrons cause a first diffraction peak at angle of 11.3 degrees...so therefore what is the interplanar spacing of the KCl??

im pretty sure the braggs formula has got to be implemented but unsure how??it couldn't be as simple as rearranging the bragg formula to get the d vaule could it?

2 d sin theta = n lambda

so basic info is that electrons are accelrated by 100v from rest
de broglie wavelength is (1.23 x 10 ^-10) m
and the first diffraction peak is at 11.3 degree angle

please, would apreciate ur ideas and help!

 

[NateD]

Yes, you can use the Bragg's formula to calculate the interplanar spacing of the KCl. The formula is 2d*sin(theta) = n*lambda, where d is the interplanar spacing, theta is the angle of incidence, n is an integer (usually 1 for the first peak), and lambda is the de Broglie wavelength. You can rearrange this equation to solve for d:d = n*lambda / (2*sin(theta))In your case, n = 1, lambda = 1.23 x 10^-10 m, and theta = 11.3 degrees. Plugging these numbers in, we get:d = 1*1.23 x 10^-10 m / (2*sin(11.3)) = 5.21 x 10^-10 m