How do I calculate the volume of an irregular container using styrofoam beads?

[tkettlehut]

I'm trying to find the volume of a irregularly shaped container by using very small styrofoam beads. Things I know: Cylinder A filled with water @ 18 c - net weight - 1231.0 g. Cylinder A filled with beads - net weight - 22.0 g. My unknown volume container holds 1678.7 g of beads. How the heck do I determine the volume of my container with this information?

 

[Werg22]

Of course, you are asked for an inexact solution. You need to make the assumption that the (weight of container filled with water) : (weight of container filled with Styrofoam beads) ratio is unchanged across containers. Are you sure this not a homework question?

 

[tkettlehut]

I wish - I'm 23 years removed from college, (forgot more than I've learned) and I'm trying to get this answer for a problem at my job.

 

[ice109]

huh? i don't understand what information you have? you know how much the water weighs that fills the container?if you do then the volume of your container is that weight divided by the density of water.

 

[CRGreathouse]

I'm trying to find the volume of a irregularly shaped container by using very small styrofoam beads. Things I know: Cylinder A filled with water @ 18 c - net weight - 1231.0 g. Cylinder A filled with beads - net weight - 22.0 g. My unknown volume container holds 1678.7 g of beads. How the heck do I determine the volume of my container with this information?

So you have

A: 22g of beads = 1231g of water
B: 1678.7g of beads

If the bags fill similarly, then we'd expect bag B to hold 1678.7g * (1231 / 22) = 93931g of water. Water is roughly 1 mL/g -- at 18 degrees I think it's a little more, but the error in the bead/water conversion is probably large enough that I wouldn't bother -- making the volume 93931 mL = 93.931 L. This probably has no more than 2 significant decimal places, so I'd report it as 94 liters of capacity.

 

[CRGreathouse]

If the containers are rigid (like a metal box instead of a backpack), then there's little enough error that dealing with the temperature makes sense. http://faculty.uccb.ns.ca/chowley/chem201/dh20vstemp.htm has densities for water based on temperature. In particular, it gives 0.998595 g/mL at 18 degrees C, giving volume per gram 1.00140698 mL/g. That gives a total volume of 94.063 liters.