In an acid-base titration, 45.78 ml of HCl solution is titrated to the end point by 37.15ml of 0.4388M NaOH solution. What is the molarity of the HCl solution? 1. 0.1780M
2. 0.3561M
3. 0.4388M
4.0.7122M
5. 0.7430M​

20 atm / (R . 321 K . i) = M

Explanation:

Osmotic pressure is a colligative property which is determined by the solute.

Solutes over solutions, can increase the osmotic pressure which is calculated like this:

P = M . R . T

where P is pressure, M is molarity, R the Universal Constant Gases and T, the absolute Temperature. We also have to consider the Van't Hoff factor, i, numbers of ions dissolved. Ionic salts determine more osmotic pressure than organic compounds, where i = 1. Then, the complete formula is:

π =  M . R . T . i

To determine molarity, osmotic pressure divide all the terms:

20 atm / (R . 321 K . i) = M

R = 0.082 L.atm/mol.K

If you see all the units in R, they will be cancelled, so finally the answer will be mol/L, which is molarity. The i term has no unit!.