- #1
ghelman
- 14
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Hi all,
I need to solve this problem for my environmental chemistry class. It is supposed to be a "review" problem of concepts from analytical and gen. chem. but I certainly do not know how to do it.
If you work at the wastewater treatment plant, you are exposed to 1,4-dichlorobenzene, which is used in urinal deodorant cakes.
a. If you work in a 500 m3 space with an exposed body of wastewater and can still smell the DCB (smell threshold 500 ppbv) what is the concentration of DCB in the water?
b. In the winter the temperature of the water falls to 5C and you can no longer smell the DCB; what is the maximum concentration of DCB in the water at the new temperature?
V=500 m3
CDCB=500 parts per billion by volume
P=1 atm (assumably)
I assume that the wastewater plant operates at a temperature of 25o C. I am not sure if that is a good assumption or not. Anyone have any insight to that?
I also assumed that the system is in equilibrium. I am not sure if I am allowed to assume that, but it seems reasonable. Doing so gives:
Vapor pressure of DCB = 1.76 mm Hg
At this point I do not know what to do. I have a concentration for DCB in air, but how do I relate that to the concentration of DCB in water at equilibrium?
I know that the fugacities will be equal at equilibrium, but I am not sure whether that will be useful or if it is just a wild goose chase.
Help!
Thanks in advance!
I need to solve this problem for my environmental chemistry class. It is supposed to be a "review" problem of concepts from analytical and gen. chem. but I certainly do not know how to do it.
Homework Statement
If you work at the wastewater treatment plant, you are exposed to 1,4-dichlorobenzene, which is used in urinal deodorant cakes.
a. If you work in a 500 m3 space with an exposed body of wastewater and can still smell the DCB (smell threshold 500 ppbv) what is the concentration of DCB in the water?
b. In the winter the temperature of the water falls to 5C and you can no longer smell the DCB; what is the maximum concentration of DCB in the water at the new temperature?
The Attempt at a Solution
V=500 m3
CDCB=500 parts per billion by volume
P=1 atm (assumably)
I assume that the wastewater plant operates at a temperature of 25o C. I am not sure if that is a good assumption or not. Anyone have any insight to that?
I also assumed that the system is in equilibrium. I am not sure if I am allowed to assume that, but it seems reasonable. Doing so gives:
Vapor pressure of DCB = 1.76 mm Hg
At this point I do not know what to do. I have a concentration for DCB in air, but how do I relate that to the concentration of DCB in water at equilibrium?
I know that the fugacities will be equal at equilibrium, but I am not sure whether that will be useful or if it is just a wild goose chase.
Help!
Thanks in advance!