Suppose the total pressure in a bottle of soda water before it is opened is 35 p

Question

Suppose the total pressure in a bottle of soda water before it is opened is 35 psig and that the gas mixture is 75% CO_2and 25% other gases. The temperature is 5degree C. The Henry's Law constant for CO_2 is 29.4 atm.L/mol. If the system is in equilibrium, what is the saturated mass concentration of CO_2 dissolved in the soda? (For this problem, ignore reactions between the CO_2 and the water) Answer about 6500 mg/L. Calculate the new equilibrium concentration when the bottle is opened The volumetric fraction of CO_2 in the normal atmosphere is 400 ppmv. Knowing this, explain why the CO_2 acts as it does when the bottle is opened.

Explanation / Answer

According to the Henerys law,

C=H*p

where C is the concentration of the gas component in the liquid

H is the Henerys constant

p is the partial pressure of the component in gas phase

This partial pressure according to the Raults law is

P = x * p

where P is the total pressure of the gas, x is the mole fraction of the component in gas phase. and p is the partial pressure

a] Here given is H = 29.4 atm L/mol = 10/29.4 mol/atm L = 0.03401 mol/atm L = 3.4031*10^-4 mol/m3 Pa.

And Total pressure = 35 psig and mole fraction of Co2 = 0.75

Thus from Raoults law, p= 0.75* 35 = 26.25 psig = 180987.45 Pa

And from Henerys law, C= 3.4031*10^-4*180987.45 mol/m3 = 58.18 mol/m3

1 mol of CO2 is 44 gms, So, C= 58.18*44 gms/m3 = 2559.92 gm/m3 = 2.559 mg/L

b] Total pressure = 1 atm = 101325 Pa and x = 400 ppmv = 4*10^-4

  

From Raoults law, p = 101325*4*10^-4 = 46.53 Pa

So from Henerys law C= 3.4031* 10^ -4 *46.53 mol/m3 = 0.01379 mol/m3 = 606 ppm

=

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.