• Support PF! Buy your school textbooks, materials and every day products Here!

Confused about the volume of a rigid (glass) container

  • Thread starter sp3sp2sp
  • Start date
  • #1
100
4

Homework Statement


This is for a lab report and I am just confused about how I should regard volume because this issue is affecting 3 other questions. If you heat a gas in a closed flask that is connected to a manometer with water in it, the water level goes up (the arm open to atmosphere rises and arm connected to flask goes down). But it now asks about the volume, as I heat the gas. Does it change? Its a glass flask so obviously the volume in flask wont or cant change but the gas excerts pressure through a rubber tube connected to arm of manometer and that causes water level to rise.
So should I consider that the Volume of the gas does change? Because the gas has expanded into the tubing right? ..Or should I say V of gas does not change? Because the gas is in a rigid container that has fixed volu?

I know that increased T will increase P if V kept constant and that if P kept constant V must increase to compensate. But I dont understand how I should regard the gas in this apparatus. Is it constant or not?
Thanks for any help

Homework Equations




The Attempt at a Solution

 

Answers and Replies

  • #2
Ygggdrasil
Science Advisor
Insights Author
Gold Member
2019 Award
2,999
2,453
Generally, you can assume that the change in volume due to the manometer should be negligible compared to the total volume of the flask.
 
  • #3
808
281
Hi ! A couple of thoughts...

A volumetric flask is calibrated at a specific temperature, usually 20'C, due to expansion, resulting flexing etc. There will not be much change around ambient conditions, but be aware and log the temperature for reference.

When we tested 'collapse revival' ampoules and collected the gas in a manometer, beside correcting for ambient temperature and atmospheric pressure, we levelled the menisci to equilibrate internal and external pressures...
 

Related Threads on Confused about the volume of a rigid (glass) container

  • Last Post
Replies
1
Views
3K
Replies
2
Views
9K
Replies
1
Views
2K
  • Last Post
Replies
1
Views
5K
Replies
6
Views
4K
Replies
11
Views
3K
  • Last Post
Replies
3
Views
967
  • Last Post
Replies
3
Views
1K
Replies
3
Views
1K
Replies
2
Views
949
Top