B Calculate length of side of cube

[Omsin]

How can I calculate the length L of each side of a cubic simulation box with 500 molecules (in Ångstrøm) when I want molar volumes of V1 = 0.6 l/mol?

 

[sophiecentaur]

How many molecules in 1 mol? What fraction of 1 mol is 500molecules? That gives you the volume of the cube in l.
V=l² will give you the length of a side of the cube.
All you need to do is the Arithmetic -get the units right, of course,

 

[Omsin]

1 mole is 6.002e+23 molecules. 500 molecules have 8.3e-22 moles. I am not really sure what you meant after that. Volume = (liter)^2? Isn't Volume[m^3] = [1000* Liter]

 

[sophiecentaur]

1 mole is 6.002e+23 molecules. 500 molecules have 8.3e-22 moles. I am not really sure what you meant after that. Volume = (liter)^2? Isn't Volume[m^3] = [1000* Liter]

My bad. Of course volume is cubed. But the sums are easy, no?

 

[Omsin]

My bad. Of course volume is cubed. But the sums are easy, no?

Sorry, but I am not really sure how to do this.

 

[DoItForYourself]

You have already calculated how many moles will be in your cube (8.3e-22 moles as you previously said).

You want molar volume of 0.6 Liters/mol, so if you multiply this number with the moles, you will get the volume of the cube (V) in Liters. Then you can divide by one thousand to get the Volume in m³.

So, your cube's side will have length $l = \sqrt[3] V$ meters.

The last step is to change meters to Angstroms.

 

[sophiecentaur]

Sorry, but I am not really sure how to do this.

Sorry. I was busy and couldn't get back to you quickly. But @DoItForYourself has sorted you out I think.