The cylinder contains two liquids that do not mix with one another: water (density = 1.0 g/mL) and vegetable oil (density = 0.93 g/mL). Four different pieces of plastic are added to the cylinder. Which type of plastic is at the position indicated by the square object in the figure? (LO 1.10) (a) Polyvinyl chloride (density = 1.26 g/mL) (b) Polypropylene (density = 0.90 g/mL) (c) High-density polyethylene (density = 0.96 g/mL) (d) Polyethylene terephthalate (density = 1.38 g/mL)

Video transcript

Hi everyone. This problem reads a flask contains hexane with the density equal to 0.66 g per middle leader and water density equals one g per milliliter. These liquids do not mix together. Different materials are added to the flask, identify the material indicated by the square object in the figure below. Okay, so our goal here is to identify the material of the square object. So here is our square object in our in our diagram or a figure here. Okay, so let's recall that density is equal to mass over volume. Okay. And based on the figure, the square object is floating on the top of the flask. So when we're looking at the densities that were given in the problem, we're told the density of hexane is 0.66 g per middle liter. And the density of water is point or one g per middle liter. Okay, so that means hexane is less dense than water. So we can assume that the top liquid is hexane. So let's go ahead and write that here. So hexane. Let's write it in black. So it's clearer. So we have hex ain is going to be this top Um liquid and it has a density of 0.66 g Per mil liter and the water will be below. Okay. And it has a density of one gram per mil leader. Okay, so foreign object to float on top of the hexane as in our square object here, it must have a lower density than hexane. And we know what the density of hexane is. And so this square object should have a lower density of hexane, since it's floating on top of it. So based off of the answer choices, given the only one that has a lower density than hexane is going to be answer choice C. Okay. So the material is poly poly urethane, with a density of .06 g per mil leader. Okay, and that is going to be the answer to this problem, and that is the end of this problem. I hope this was helpful.