Question

1. The Henry’s Law constant for O2 is 770 L atm mol-1 at 25 °C. What mass of oxygen would be dissolved in a 40-L aquarium at 25 °C, assuming an atmospheric pressure of 1.00 atm, and that the partial pressure of O2 is 0.21 atm?

2.The carbon dioxide concentration in a bottle of club soda is 0.12 mol L-1 at 25 °C. What is the pressure of carbon dioxide in the headspace? The Henry’s Law constant for CO2 at 25 °C is 3.4 x 10-2 mol L-1 bar-1 .

Answer 1

Ale to Henry's law, at constant temperature, Pgas & C gas Pgas = ke Cgas Igas : partial pressure of gas Cgas : Concentration of gas dissolved in a solvent Ku : Henry's law constant 1. Pgas = 0.21 atin KH = 770 Latu molt : 0.21 atm = 770 Latu mot" x Cgas => Cgas = 2.727 X10-Y molla Cgas = 2.7 = 2.727 x 10-'mof x 322 mean = 8.7264 X10-8914 mas o q in I Lor 1000 ml = 8.7264X10-39 mass & Q in 402 = 8.7264 X10-3 x 40 = 0.349 g Thus, 0.349g Oz would be dissolved in a 40. aquarium. IL . I mol