Question

I think O2 is nonpolar and its soluble in water, but can you explain why its soluble in water?

Answer 1

O2 is considered to have a VERY low solubility in water

Solubilty of gases depend on:

- Temperature, normally, the higher temperature, the least gas in solution, and backwards

- Pressure, the more pressure (partial pressure) of the gas, the higher solubility it will have on solution

For O2

H = 1.3*10^-3 M/atm

P°O2 in atm = 0.21 atm

then

M = H*P

M = (1.3*10^-3)*0.21 = 0.000273 mol of O2 per liter;

mas S= mol*MW = 0.000273*32 = 0.008736 g per liter = 8.73 mg per liter or 8.73 ppm!

NOTE that in general, "not soluble" and "soluble" are expressions used for convenience

in real life all substnaces are soluble for a certain extent,

it is an equilibrium descirbed mathematically as

AB <--> A+ and B-

Ksp = [A+][B-]

for pretty low value of Ksp, this will be non soluble for convinence puropose