Answer: Henry's law states that the solubility of a gas in a liquid is proportional to the partial pressure of the gas over the solution. The relationship can be represented by the equation:
C = kP
where C is the concentration of the gas (in mol/L), k is the Henry's law constant, and P is the partial pressure of the gas.
Given that the mole fraction of oxygen in water is 0.210, the partial pressure of oxygen in the solution is:
P = 0.210 * 1 atm = 0.210 atm
Since the Henry's law constant for oxygen at 25 ∘C is 1.3 × 10^(-3) M/atm, the concentration of oxygen in water can be calculated as:
C = 1.3 × 10^(-3) M/atm * 0.210 atm = 0.000276 M
Finally, the mass of oxygen dissolved in 120.0 L of water can be calculated as:
mass = C * volume * molecular weight of oxygen
= 0.000276 M * 120.0 L * 32.0 g/mol
= 10.57 g
Step-by-step explanation: