In: Other
2. A solution of 500 kg of Na2SO4 in 2500 kg water is
cooled from 333 K to 283 K in an
agitated mild steel vessel of mass 750 kg. At 283 K, the solubility
of the anhydrous salt
is 8.9 kg/100 kg water and the stable crystalline phase is
Na2SO4.10H2O. At 291 K,
the heat of solution is −78.5 MJ/kmol and the specific heat
capacities of the solution
and mild steel are 3.6 and 0.5 kJ/kg deg K respectively. If, during
cooling, 2 per cent
of the water initially present is lost by evaporation, estimate the
heat which must be
removed. (use both methods)
I have taken some formula and value from standard textbook which will help you to understand the process.You can go through any standard textbook of crystallisation for getting the derivation of the formula.