Density of Magnesium Strontium Alloy (MgSr) in BCC Structure

[JulianA2]

Hi!

I am a freshman in college on my first week of an intro chemistry course. I think the professor may have made a mistake with the software that generates the problem sets, but I'm giving it a shot regardless.

One of the questions is: An alloy with a 1:1 ratio of magnesium and strontium crystallizes in the bcc CsCl structure. The unit-cell edge of MgSr is 390 pm. What is the density of MgSr?

So I looked in my textbook (in the last chapter...) and found an example of how to do this with a fcc unit cell. I followed that example and got the wrong answer, so the amount of atoms in a bcc cell must be different.

Could you please help me with this problem?

Thanks,
Julian

 

[SteamKing]

Hi!

I am a freshman in college on my first week of an intro chemistry course. I think the professor may have made a mistake with the software that generates the problem sets, but I'm giving it a shot regardless.

One of the questions is: An alloy with a 1:1 ratio of magnesium and strontium crystallizes in the bcc CsCl structure. The unit-cell edge of MgSr is 390 pm. What is the density of MgSr?

So I looked in my textbook (in the last chapter...) and found an example of how to do this with a fcc unit cell. I followed that example and got the wrong answer, so the amount of atoms in a bcc cell must be different.

Could you please help me with this problem?

Thanks,
Julian

Yes, different crystal structures contain different numbers of atoms.

Check out this article (at the bottom where it discusses unit cells):

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch13/unitcell.php

 

[Borek]

Could you please help me with this problem?

Please read the forum rules. The best approach is to post the problem and your attempt at solution in the homework section, and we will start from there. At the moment there is not much that we can help you with.