Question

Henry’s law constant for CO₂ in water is 1.67 × 10⁸ Pa at 298 K. Calculate the number of moles of CO₂ in 540 g of soda water when packed under 3.34 × 10⁵ Pa at the same temperature.

Answer 1

Given: K_H = 1.67 × 10⁸ Pa

`P_(CO_2)` = 3.34 atm = 3.34 × 10⁵ Pa

Mass of water = 540 g

Formula: `P_(CO_2) = K_H chi`

`chi =P_(CO_2)/(K_H)`

= `(3.34 xx 10^5)/(1.67 xx 10^8)`

= 2 × 10³

`n_(H_2O) = 540/18  "mol of water"`

= 30 mol of water

∴ `chi = (n_(CO_2))/(n_(H_2O))`

`n_(CO_2) = chi xx (n_(H_2O))`

`n_(CO_2) = 2 xx 10^-3 xx 30` 

= 60 × 10⁻³

= `60/1000`

= 0.06 moles