Henry’s law constant for CO2 in water is 1.67x108 Pa at 298 K. Calculate the quantity of CO2 in 500 mL of soda water when packed under 2.5 atmCO2 pressure at 298 K.
According to Henry's law,
"At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid."
Stated as,
p = KHx
Where,
P = partial pressure of the solute above the solution
KH = Henry's constant
x = concentration of the solute in the solution
Given,
KH = 1.67x108 Pa
PCO2 2.5 atm = 2.5 × 1.01325 × 105Pa
According to Henry's law,
p = KHx
x = 0.00152
In 500 ml of soda water there is 500 ml of water (neglecting soda)
Mole of water =
= 27.78 mol
Now,
x =
nCO2 = x nH2O
= 0.00152 × 27.78
= 0.042 mol
Hence, quantity of CO2 in 500mL of soda water 0.042 × 44 = 1.848 g