1. Foundations

Material Balances — Quiz

Test your understanding of material balances with 5 practice questions.

Practice Questions

Question 1

In a continuous steady-state process involving a reactor with a recycle stream, if an inert component is introduced with the fresh feed and is not consumed in the reactor or removed in the product, what is the most effective strategy to prevent its continuous buildup in the system?

Question 2

Consider a continuous reactor where a reactant A converts to product B. The fresh feed to the process is $150 \text{ mol/h}$ of pure A. The conversion of A per pass through the reactor is $60\% $. A recycle stream returns unreacted A to the reactor inlet. If the total feed to the reactor (fresh feed + recycle) is $300 \text{ mol/h}$ of A, what is the molar flow rate of the recycle stream in $ \text{mol/h}$?

Question 3

A process unit separates a feed stream of $500 \text{ kg/h}$ containing $30\%$ ethanol and $70\%$ water. The top product stream contains $80\%$ ethanol and $20\%$ water. The bottom product stream contains $5\%$ ethanol and $95\%$ water. What is the mass flow rate of the top product stream in $ \text{kg/h}$?

Question 4

Which of the following scenarios most clearly represents an unsteady-state process in terms of material balances?

Question 5

In a chemical process with a recycle stream, what is the primary reason for sending a portion of the product stream back to an earlier stage of the process?