A metal crystallizes into two cubic phases , face-centred cubic (fcc) and body -centred cubic (bcc) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratioof the densities of fcc and bcc.

A metal crystallizes into two cubic phases , face-centred cubic (fcc)

1.	A metal crystallizes into two cubic phases , face-centred cubic (fcc) and body -centred cubic (bcc) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratioof the densities of fcc and bcc.
Answer» <html><body><p></p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/density-17451" style="font-weight:bold;" target="_blank" title="Click to know more about DENSITY">DENSITY</a> `(<a href="https://interviewquestions.tuteehub.com/tag/rho-623364" style="font-weight:bold;" target="_blank" title="Click to know more about RHO">RHO</a>)=(ZxxM)/(a^3xxN_0)` <br/> For fcc, Z=4,a=<a href="https://interviewquestions.tuteehub.com/tag/3-301577" style="font-weight:bold;" target="_blank" title="Click to know more about 3">3</a>.5 Å =`3.5xx10^(-8)` cm <br/> `therefore rho_"fcc"=(4xxM)/((3.5xx10^(-8))xxN_0)` <br/> For bcc, Z=2, a=3.0 Å =`3.0xx10^(-8)`cm <br/> `therefore rho_"bcc"=(2xxM)/((3.0xx10^(-8))^3xxN_0) therefore rho_"fcc"/rho_"bcc"=(<a href="https://interviewquestions.tuteehub.com/tag/4xx-1883349" style="font-weight:bold;" target="_blank" title="Click to know more about 4XX">4XX</a>(3.0xx10^(-8))^3)/(<a href="https://interviewquestions.tuteehub.com/tag/2xx-1840186" style="font-weight:bold;" target="_blank" title="Click to know more about 2XX">2XX</a>(3.5xx10^(-8))^3)=1.259`</body></html>