why do we need to use Over-water method to collect the carbon dixode Watch

universalcj
Badges: 1
Rep:
?
#1
Report Thread starter 3 weeks ago
#1
In the book they carry out the practical to measure the volume of carbon dioxide by using Over-water method. Why do we use over water method to collect carbon dioxide gas.
Also, can I ask how can we decide what methods suit the best in the experiment. ( over-water, down ward delivery, upward delivery)
Last edited by universalcj; 3 weeks ago
0
reply
PetitePanda
Badges: 19
Rep:
?
#2
Report 3 weeks ago
#2
So the gas doesn’t go out or react with the atoms in the air.
0
reply
Pigster
Badges: 17
Rep:
?
#3
Report 3 weeks ago
#3
(Original post by universalcj)
In the book they carry out the practical to measure the volume of carbon dioxide by using Over-water method. Why do we use over water method to collect carbon dioxide gas.
Also, can I ask how can we decide what methods suit the best in the experiment. ( over-water, down ward delivery, upward delivery)
CO2 is soluble (a bit) in water, so isn't perhaps the best method (I'd use a gas syringe) as some of the CO2 will be lost (dissolved).

It is a whole load better than upwards delivery (since CO2 is more dense than air, so would just fall out). And quite a lot better than downwards delivery as at least the CO2 would collect in the jar. Both upwards and downwards deliveries are poor as the gas collected will not be pure and you never really know when the jar is full.

Over water is an easy setup requiring no expensive and easy to break equipment (I don't much want to let bottom set year eight near a gas syringe).
0
reply
universalcj
Badges: 1
Rep:
?
#4
Report Thread starter 3 weeks ago
#4
(Original post by Pigster)
CO2 is soluble (a bit) in water, so isn't perhaps the best method (I'd use a gas syringe) as some of the CO2 will be lost (dissolved).

It is a whole load better than upwards delivery (since CO2 is more dense than air, so would just fall out). And quite a lot better than downwards delivery as at least the CO2 would collect in the jar. Both upwards and downwards deliveries are poor as the gas collected will not be pure and you never really know when the jar is full.

Over water is an easy setup requiring no expensive and easy to break equipment (I don't much want to let bottom set year eight near a gas syringe).
oh ya. so out of three methods that I mentioned, Nevertheless CO2 gas collected might dissolve into water, over water is still the best to check the volume of the gas and collect the pure gas. Thank you for kind and informative answer. Have a good day
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • Bournemouth University
    Midwifery Open Day at Portsmouth Campus Undergraduate
    Wed, 16 Oct '19
  • Teesside University
    All faculties open Undergraduate
    Wed, 16 Oct '19
  • University of the Arts London
    London College of Fashion – Cordwainers Footwear and Bags & Accessories Undergraduate
    Wed, 16 Oct '19

How has the start of this academic year been for you?

Loving it - gonna be a great year (131)
17.99%
It's just nice to be back! (197)
27.06%
Not great so far... (263)
36.13%
I want to drop out! (137)
18.82%

Watched Threads

View All