What Is the Volume of a Gas Bubble Just Beneath the Surface of Mercury?

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Homework Help Overview

The problem involves determining the volume of a gas bubble just beneath the surface of mercury in a container, taking into account the depth of the mercury and the temperature difference between the top and bottom of the container.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the application of the ideal gas law and hydrostatic pressure equations. There is a focus on clarifying which labels correspond to the top and bottom of the container. Questions arise regarding unit conversions for depth and volume, as well as the implications of the bubble's position in the fluid.

Discussion Status

The discussion is ongoing, with participants providing feedback on each other's calculations and clarifying misunderstandings about the problem setup. There is no explicit consensus yet, but some productive guidance has been offered regarding unit conversions and the interpretation of the problem.

Contextual Notes

Participants are working under the constraints of homework rules, which may limit the information they can share or the methods they can use. There are noted discrepancies between the original poster's calculations and expected answers, prompting further exploration of the problem.

greyknight
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Homework Statement


A gas bubble with a volume of 0.10 cm^3 is formed at the bottom of a 10.0 cm deep container of mercury. If the temperature is 27C at the bottom of the container and 37C at the top of the container, what is the volume of the bubble just beneath the surface of the mercury? assume that the surface is at atmospheric pressure.


Homework Equations


P1V1/T1=P2V2/T2
P=Po+pgh

The Attempt at a Solution



P2=Po+pgh
P2= 1.01x10^5Pa + (13.6x10^3kg/m3)(9.81m/s)(1.0x10^-3m)
P2= 101130Pa

P1V1/T1=P2V2/T2 > V2=P1V1T2/T1P2

V2=(1.01x10^5Pa)(1.0X10^-3 m^3)(300K)/(310K)(101130Pa)

V2=9.66x10^-4 m^3

The answer in the back differs with mine and I have tried to redo the problem many times.
 
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Hi greyknight, welcome to PF :smile:

Firstly, What do your labels 1 and 2 refer to? Which is bottom and which is top?

Secondly,

greyknight said:
P2= 1.01x10^5Pa + (13.6x10^3kg/m3)(9.81m/s)(1.0x10^-3m)

What is 1.0x10^-3 m?

Finally,
V2=(1.01x10^5Pa)(1.0X10^-3 m^3)(300K)/(310K)(101130Pa)

What is 1.0x10^-3 m^3?
 
Label 1 is the top and label 2 is the bottom.

1.0x10^-3 m is the depth of the container. Originally 10.0 cm but I converted it to meters.

1.0x10^-3 m^3 is the volume of the bubble on top converted from 0.10 cm^3.
 
greyknight said:
Label 1 is the top and label 2 is the bottom.

Well, in that case you are trying to find the volume V2 at the bottom, but the question asks you for the volume at the surface. Bubbles rise up! :smile:

1.0x10^-3 m is the depth of the container. Originally 10.0 cm but I converted it to meters.

Check this conversion. 1x10^-3 m = 1/1000 m = 1mm.

1.0x10^-3 m^3 is the volume of the bubble on top converted from 0.10 cm^3.

Check this conversion also. How do you convert cm^3 to m^3?
 
greyknight said:
1.0x10^-3 m is the depth of the container. Originally 10.0 cm but I converted it to meters.

10 cm = 0.1 m

greyknight said:
1.0x10^-3 m^3 is the volume of the bubble on top converted from 0.10 cm^3.

0.1 cubic centimeter = 1.0e-7 cubic meter

I divided 0.10 by 100x100x100 or 0.10/100^(3)
 
Wow, that was just a lot of sloppy math by me. Thanks, naresh. :)
 
do you get the answer?
 

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