Unformatted text preview: ChE 501 Fall 2016 HW Assignment 16 Solution 1. Copper sulfate CuSO4 precipitates from aqueous solution as copper sulfate
pentahydrate CuSO4-5H20. Assume that the solubility limit of copper sulfate is 0.950 M
independent of temperature and that the specific gravity of the saturated solution is 1.10. A saturated solution of copper sulfate in water enters an evaporator at a rate of 50.0 Uh.
In the evaporator it is heated to the boiling temperature, and 30.0 % of the water is
removed and leaves the evaporator as steam. The remainder of the liquid stream leaves
the evaporator carrying precipitated copper sulfate pentahydrate crystals. This stream is
fed to a ﬁlter where all of the crystals are removed in the filter cake. The cake also
contains 10 wt % saturated solution. Finally the wet cake is heated until all of the liquid
water evaporates, leaving only copper sulfate pentahydrate crystals. Find the boiling temperature of the saturated solution. Find the mass flow rate of copper sulfate pentahydrate crystals leaving the process. 2 M4 kglh
0.130 kg Cuso. lkg M2 kg H20 Ih 55.0 kglh
0.130 kg CuSO4 Ikg M3 kg solnlh
0.130 kg CuSO4 Ikg Mc kg CuSO4-5H20 M5 kg solnlh
0.130 kg CuSO4 lkg Mc kg CuSO4-5H20 Convert the volume ﬂow-rate to mass ﬂow-rate and the saturated concentration to mass
fraction. M1: 1.10-kg‘50.0-L=55.0.kg/h L x _0.95-mol-CuS04 0.16O-kg-CuS04 L-soln —0138-k -CuSO /k -soln
s L moi-CuSO4 1.10-kg-soln ‘ g 4 g The mass fraction of copper sulfate in the pentahydrate is, ...
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