The osmolality of the solution is 304 mOsmol/kg.
An osmole (Osmol) is 1 mol of particles that contribute to the osmotic pressure of a solution.
The problem here is how to convert equivalents to osmoles.
The point to remember is that 1 eq of anything reacts with or produces 1 eq of anything else
We see that
For ions, the rule is,
Now, let's use this relationship to calculate the osmolarity of the solution.
Assume we have 1 L of solution.
We will set up a table for easy calculation.
Note that there are 153 meq of cations and 153 meq of anions, as required.
Since the solution is so dilute, its density is almost the same as that of water, and the mass of the water is approximately 1 kg.
∴ The concentration is also 304 mOsmol/kg.