# Density conversion from ounces and L to g per mL

Submitted by Yazzy368 on Sun, 02/08/2009 - 20:10

:-\

I am confused about a problem - it's so easy & hard @ the same time.

An object has a mass of 3.15 oz and a volume of 0.1173 L.  What is the density (g/mL) of the object?

The answer key states the following:
#1) 442.5 mL total - 325.2 mL water = 117.3 mL = volume of object

#2) 3.15 oz objects/117.3 mL object x 1 lb/16 oz x 454 g/ 1 lb = 0.762 g/mL

I understand #2, but not #1.  Could you provide an explanation for #1?

Thank you!

water displacement is a technique used to measure the volume of usually irregular shaped objects like rocks

say you have 50 mL in a graduated cylinder and you add a rock, what do you expect to happen?

the water level to rise

the difference is the volume of the stone

what is the density, in grams per mililiter, of a salt solution if 75.0 mL has a mass of 87.5 g? I kinda understand how to solve it but I'm confused on where or how to find how many grams are in mililiter

Density = 87.5g / 75.0mL = 1.17g/mL