Question

The following solutions are prepared by dissolving the requisite amount of solute in water to obtain the desired concentrations. Rank the solutions according to their respective osmotic p complete dissociation of ionic compounds. Rank from highest to lowest osmotic pressure. To rank items as equivalent, overlap them. View Available Hint(s) Reset Help Highest osmotic pressure Lowest osmotic pressure 1 M MgCl2 1 M KCI 1 M C12 H22011

Answer 1

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