The solubility of hydrogen under normal conditions is 0.09 g in 1 dm3 of water.

The solubility of hydrogen under normal conditions is 0.09 g in 1 dm3 of water. Calculate how many water molecules are there per hydrogen molecule in such a solution.

The mass of one liter of water is 1000 grams. Let us find how much of a water substance corresponds to this mass:

n (H2O) = m (H2O) / M (H2O) = 1000/18 = 55.56 mol;

Let’s find the amount of hydrogen substance:

n (H2) = m (H2) / M (H2) = 0.09 / 2 = 0.045;

The ratio between the amounts of water substance and dissolved hydrogen will show how many water molecules there are per one molecule of dissolved gas:

n (H2O): n (H2O = 55.56: 0.045 = 1234.7: 1

Answer: There are approximately 1235 water molecules per dissolved hydrogen molecule.