Estimate the mole fraction of dissolved CO2 in an ordinary s

Estimate the mole fraction of dissolved CO_2 in an ordinary soft drink at 4.0 degree C. Assume that the partial pressure of CO_2 in the gas phase is 2 atm. Neglect the reaction between CO_2 and water. We will revisit this approximation and find that it is safe to neglect. Approximate answer: 0.002.

Solution

According to Henry law,

k=(concentration of Co₂ in air) /(concentration of Co₂ in solution state)

where k is called Henry constant

at 25 ^O C ,k for Co₂and water is 1640 atm_.

_{at 4}^O C,k for Co₂and water is 1058 atm

(from standard table )

1058=2 /(concentration of Co₂in solid state)

concentration of Co₂in solid state = (2/1058) =0.0018

approximately 0.002atm