Q59

Two ideal cross- current stages operate to extract P from a feed containing P and Q, as shown below. Pure solvent (S) Feed (P+Q)RaffinateRaffinate Stage 1Stage 2 ExtractExtract The mass flow rates of P and Q to stage 1 are 1,000 kg h ⁻¹ and 10,000 kg h⁻¹, respectively. Pure solvent (S) is injected at mas flow rates of 5,000 kg h⁻¹ and 15,000 kg h⁻¹ to stages 1 and 2, respectively. The components Q and S are immiscible. The equilibrium relation is given by Y*=1.5X, where X is the mass of P per unit mass of Q in the raffinate, and Y* is the mass of P per unit mass of S in the extract, which is in equilibrium with the raffinate. The mass flow rate of P (in kg h ⁻¹) in the raffinate from state 2 is ____(round off to nearest integer).

Let x amount left in the Raffinate remaining from stage – 1 then in the extract, it will be (1000−x)

3.5x=2000

Amount of solute x=175.024 In Raffinate = 176 Hence, the correct answer is 176.