Question #44723

A globular metalloprotein exists as a tetramer ($M_w = 60,000 \text{ g mol}^{-1}$). In its native folded state, the tetramer completely sequesters $4$ molecules of a non-electrolyte cofactor and $2$ formula units of $\ce{Fe2(SO4)3}$ deep within its hydrophobic core. These sequestered species are tightly bound and do not contribute to the initial osmotic pressure.

An aqueous solution is prepared by dissolving $15.0 \text{ g}$ of this protein in $500 \text{ mL}$ of water at $300 \text{ K}$. Under severe osmotic stress, the protein completely denatures, dissociating into its $4$ monomeric chains and releasing all sequestered species into the aqueous medium. The released $\ce{Fe2(SO4)3}$ undergoes complete ionization.

Assuming the volume remains constant, what is the osmotic pressure of the solution after complete denaturation? (Given: $R = 0.082 \text{ L atm K}^{-1} \text{ mol}^{-1}$)