How to measure the density of a material?

[EL AALLAOUI Najla]

Homework Statement

how to measure the density of material

Relevant Equations

please I want to know how the measure the density of material considering that I have idea just about molar mass and mass thank you in advance

ohh

 

[berkeman]

What kind of material? If you have a solid sample, first weigh it and then use volume displacement in a graduated water beaker to measure its volume?

 

[EL AALLAOUI Najla]

yes I have a powder . thank you

 

[EL AALLAOUI Najla]

but for powder this technique that you told me is useful !

 

[epenguin]

This sort of thing is covered in the most elementary school physics textbooks, or used to be.

School physics labs have 'density bottles', bottles made to exactly e.g. 50 ml with a capillary stopper to make a precise volume.

Your liquid needs to be one that has no interaction with the solid, i.e. does not adsorb it nor dissolve in it. You don't want the solid floating on the liquid either.

 

[Lord Jestocost]

Your liquid needs to be one that has no interaction with the solid, i.e. does not adsorb it nor dissolve in it. You don't want the solid floating on the liquid either.

To determine the true density of solid powder particles, one therefore generally uses a helium gas pycnometer.

 

[Bystander]

uses a helium gas pycnometer.

Helium? Not heavy inert gases; small/fixed volumes times low densities equal small masses?

 

[symbolipoint]

yes I have a powder . thank you

Easier if you can just accept Bulk Density. Weigh the volume measurement container with and without your material. Note the volume measurement. Density, or in such a case, bulk density, is mass (which in your case might need to be "weight") divided by volume.

 

[Lord Jestocost]

Helium? Not heavy inert gases; small/fixed volumes times low densities equal small masses?

"The problem with volume measurement is that object or substance isn't usually in a form of a regular shape but as a deformerd object or as a powder. Using classical method such as water diplacement isn't usually good enough since water could interact and become stuck on the sample surface. Gas pycnometry solves this by utilizing an inert gas and Boyle's gas law."

from: https://wiki.aalto.fi/display/SSC/Gas+pycnometry#cite-summary-2-1

 

[Bystander]

Looks like, but isn't a modified Burnett apparatus; will wonders never cease. http://uolab.groups.et.byu.net/files/compress/hints/BurnettMethodTheory&Apparatus.pdf