Gas solubility in water

K * 17.5 mbar)= 0.000004 mg/LIn summary, the concentrations of N2, O2, and Ar in air equilibrated water at 1000.9mbar, 20C, and 65% humidity would be 0.000401 mg/L, 0.000076 mg/L, and 0.000004 mg/L, respectively, if 10mL of air is dissolved in excess by hydrostatic pressure.
  • #1
merely
2
0
Hello,

I'm trying to get the concentration (mg/L) of N2, O2 and Ar in air equilibrated water at 1000.9mbar, 20C and 65% humidity (clear water, salinity~0) using the following literature B and k (Bunsen coef and Henry's coef):

N2
B=15.57 cc.liter-1 atm-1.
k=7.97atm*10-4.

O2
B=29.86 cc.liter-1 atm-1.
k=4.15atm*10-4.

Ar
B=34.03cc.liter-1 atm-1.
k=3.65atm*10-4.

I confuse the unities, once and again, and again, and again...

Which would be the conc (mg/L) if I dissolve 10mL of air in excess (by hydrostatic pressure).

thanks a lot,
merely
 
Physics news on Phys.org
  • #2
s

Hello merelys,

Thank you for your question. To calculate the concentration of N2, O2, and Ar in air equilibrated water at 1000.9mbar, 20C, and 65% humidity, we can use the following formula:

Concentration (mg/L) = (Partial Pressure of Gas * Henry's Coefficient * Molar Mass of Gas) / (Bunsen Coefficient * Temperature * Water Vapor Pressure)

For N2:

Partial Pressure of N2 = 1000.9mbar * 0.79 (fraction of N2 in air) = 790.71mbar
Water Vapor Pressure at 20C and 65% humidity = 17.5 mbar
Molar Mass of N2 = 28 g/mol

Substituting these values into the formula, we get:

Concentration (mg/L) = (790.71mbar * 7.97atm*10-4 * 28 g/mol) / (15.57 cc.liter-1 atm-1 * 293.15K * 17.5 mbar)

= 0.000401 mg/L

Similarly, for O2:

Partial Pressure of O2 = 1000.9mbar * 0.21 (fraction of O2 in air) = 210.19mbar
Water Vapor Pressure at 20C and 65% humidity = 17.5 mbar
Molar Mass of O2 = 32 g/mol

Substituting these values into the formula, we get:

Concentration (mg/L) = (210.19mbar * 4.15atm*10-4 * 32 g/mol) / (29.86 cc.liter-1 atm-1 * 293.15K * 17.5 mbar)

= 0.000076 mg/L

And for Ar:

Partial Pressure of Ar = 1000.9mbar * 0.01 (fraction of Ar in air) = 10.009mbar
Water Vapor Pressure at 20C and 65% humidity = 17.5 mbar
Molar Mass of Ar = 40 g/mol

Substituting these values into the formula, we get:

Concentration (mg/L) = (10.009mbar * 3.65atm*10-4 * 40 g
 

1. What is gas solubility in water?

Gas solubility in water is the ability of a gas to dissolve in water. This process occurs due to the attraction between the water molecules and the gas molecules. The amount of gas that can dissolve in water is affected by factors such as temperature, pressure, and the type of gas.

2. Why is gas solubility in water important?

Gas solubility in water is important for various reasons. It plays a crucial role in aquatic ecosystems, as it affects the concentration of gases in the water that is necessary for the survival of aquatic organisms. It is also important in industries such as wastewater treatment, where the solubility of gases like oxygen and carbon dioxide is essential for the treatment process.

3. How does temperature affect gas solubility in water?

Temperature has a significant impact on gas solubility in water. Generally, as temperature increases, the solubility of gases decreases. This is because the increased kinetic energy of the water molecules makes it more difficult for the gas molecules to dissolve and stay dissolved. Additionally, as temperature increases, the density of water decreases, meaning there is less space for gas molecules to dissolve.

4. Can gas solubility in water be affected by pressure?

Yes, pressure also affects gas solubility in water. As pressure increases, the solubility of gases also increases. This is because the increased pressure forces the gas molecules to dissolve and stay dissolved in the water. This is why carbonated drinks, which are under high pressure, have a higher concentration of dissolved carbon dioxide.

5. How is gas solubility in water measured?

Gas solubility in water is typically measured in units of concentration, such as parts per million (ppm) or milligrams per liter (mg/L). One common method of measurement is using a dissolved oxygen probe, which measures the concentration of dissolved oxygen in water. Other methods include titration or gas chromatography.

Similar threads

Replies
8
Views
3K
  • Biology and Chemistry Homework Help
Replies
2
Views
1K
  • Advanced Physics Homework Help
Replies
2
Views
2K
  • Mechanical Engineering
Replies
3
Views
895
  • Biology and Chemistry Homework Help
Replies
6
Views
1K
  • General Math
Replies
2
Views
695
  • Biology and Chemistry Homework Help
Replies
14
Views
2K
  • Biology and Chemistry Homework Help
2
Replies
48
Views
7K
  • Introductory Physics Homework Help
Replies
12
Views
685
Replies
3
Views
954
Back
Top