Material Balances: Example Problems

Try to solve these problems before watching the solutions in the screencasts.

Example Problem 1

A liquid-liquid extraction vessel is used to separate a solute (S) from water (W). The solute is transferred to an organic solvent (O) that is immiscible in water. Given the process diagram below, calculate the following:

  1. The organic solvent required to produce a water product contain 0.5% solute.
  2. The fraction of the solute in the feed that is recovered in the organic solvent product.
Image of a unit operation
Example Problem 2

A mixing tank is used to prepare a solution for a reaction. The concentration and flow rate of stream A is variable i thus a flow meter and a detector are used to ensure a specific concentration leaves the mixing tank. Use the schematic and information below to help an operator determine appropriate equations to use in their control operations for this process.