Question

If the theoretical molecular mass of the compound referred to above is 80.5 g/mol⁻¹, suggest whether it is undergoing association or dissociation.

Answer 1

To determine if a compound is undergoing association or dissociation, you must compare its theoretical molecular mass (80.5 g/mol) to its observed (experimental) molecular mass. If the observed mass is greater than 80.5 g/mol, the compound is undergoing association, as molecules are clustering together to form larger aggregates, thereby reducing the total number of particles in the solution.

Conversely, if the observed mass is less than 80.5 g/mol, the compound is undergoing dissociation, meaning it is breaking apart into smaller ions or molecules, which increases the total particle count.

 This relationship is defined by the van’t Hoff factor (i), where

i = `"Theoretical Mass"/"Observed Mass"`

A value of i > 1 indicates dissociation, while i < 1 indicates association.

To determine whether a compound undergoes association or dissociation, we compare its theoretical molar mass (80.5 g/mol) with the observed molar mass (161 g/mol).