A saturated MgSO4 solution at 130°F is fed to a crystallizer operating at 50°F. The solution leaving the crystallizer is saturated. Magnesium sulfate solubilities are 35 wt% MgSO₄ at 130°F and 23 wt% MgSO₄ at 50°F.

(a) Write the molecular formula for the crystalline product that forms. (See Table 6.5-1)

(b) A production rate of 1000 kg/h of crystalline material is desired. Calculate (i) the required feed rate to the crystallizer (kg/h) and (ii) the rate (kg/h) at which anhydrous MgSO₄ could be recovered from the crystals.