# Chemical Forums

## Chemistry Forums for Students => High School Chemistry Forum => Topic started by: calejone on February 13, 2020, 11:55:48 AM

Title: Calc volume given mass of object floating/sinking in 2 solutions w dif densities
Post by: calejone on February 13, 2020, 11:55:48 AM
I can't figure out how to set up this problem:

"An object floats in a solution whose density is 1.05 g/mL and it sinks in a solution whose density is 0.950 g/mL. Suppose that the mass of the object is 5.55 g. Which of the following could be its volume?

A.) 5.00mL
B.) 5.10mL
C.) 5.20mL
D.) 5.40mL
E.) 5.90mL

I chose D just kind of making my best guess but I'd really love to understand how to logically figure this out step by step. Any help would be greatly appreciated.
Title: Re: Calc volume given mass of object floating/sinking in 2 solutions w dif densities
Post by: AWK on February 13, 2020, 12:17:47 PM
definition of density d=m/V
You can easily calculate range of possible volumes.
Title: Re: Calc volume given mass of object floating/sinking in 2 solutions w dif densities
Post by: MNIO on February 13, 2020, 03:41:51 PM
some hints
(1) if the object floats on a liquid with density = 1.05g/mL... is the objects
density < 1.05 g/mL or > 1.05 g/mL?
(2) if the object sinks in a liquid with density = 0.950 g/mL...
is the objects density > or < 0.950 g/mL??
(3) if the objects density is between 0.950 g/mL and 1.05 g/mL,
and if the objects mass = 5.55g
can you use d = mass / V to calculate a range of V's for the object?
(4) can you sort through the list of possibilities and spot which ones fall in that range?