A 15.0 g sample of MgCO₃ is placed in a 1.0 L reaction vessel along with excess HNO₃. The following reaction then occurs at 350 K: MgCO₃(s) + 2 HNO₃(aq) → Mg(NO₃)₂(aq) + H₂O(l) + CO₂(g). Use the van der Waals equation to calculate the pressure of CO₂(g) in the vessel, taking into account the volume of the non-gaseous products. The constants for CO₂(g) are a = 3.607 atm L²/mol² and b = 0.04286 L/mol. Assume the non-gaseous products occupy a total volume of 111.6 mL.