Answer:
1M MgCl₂ > 1M KCl > 1M C₁₂H₂₂O₁₁
Explanation:
The osmotic pressure (π) is the pressure needed to impede the osmose, it means that it's the necessary pressure to prevent the solvent to go through a membrane.
It can be calculated by:
π = M*R*T*i
Where M is the molarity of the solution (mol/L), R is the ideal gas constant, T is the temperature, and i the van't Hoff factor.
This factor is a way to correct the number of particles that are dissolved in a solute, and it can be calculated by:
i = 1 + α*(q - 1)
Where α is the degree of dissociation of a substance, and q is the number of moles of each ion released in a solution. Thus, covalent compounds that didn't ionize, such as sugars, have only one particle, and q = 1, and so i =1.
Because all the substances have the same molarity (1 M) and are at the same temperature, let's analyze the value of i, which is directly proportional to π.
C₁₂H₂₂O₁₁ is a sugar that didn't ionize, so π = 1;
Both KCl and MgCl₂ are soluble salts and will dissociate completely (α = 1), but MgCl₂ will have 3 particles (Mg²⁺ + 2Cl⁻), and KCl only one particle (K⁺ and Cl⁻), so qMgCl₂ > 1KCl, and so πMgCl₂ > πKCl, which will be higher than 1.
1M MgCl₂ > 1M KCl > 1M C₁₂H₂₂O₁₁
