Where Do Chemical and Bioengineers Work?
which lists the percentages of all chemical engineers by employment sector between 1996 and 2007, shows that the percentage of chemical engineers in these developing industries (pharmaceutical, biomedical, and microelectronics…
The Chemical Reaction Equation and Stoichiometry
Stoichiometry: When chemical reactions occur, in contrast with physical changes of material such as evaporation or dissolution, you want to be able to predict the mass or moles required for…
Material Balances for a System
with More than One Component Almost all real systems involve multicomponent mixtures that require a slightly different approach for solving material balance problems than a system with a single component.…
Characteristics of Systems
By system we mean any arbitrary portion of or a whole process you want to consider for analysis. You can define a system such as a reactor, a section of…
Material Balances for a Single Component
To begin our discussion of the material balance equation, let’s consider a system composed of a single component for which there are no chemical reactions occurring. Then, the general equation,…
Concept of a Material Balance
You can get a good idea of what is involved in making a material balance by examining a bank statement such as the following one that illustrates the changes in…
Pressure and Hydrostatic Head
In Florentine Italy in the seventeenth century, well diggers observed that when they used suction pumps, water would not rise more than about 10 m. In 1642 they came to…
Temperature
You can hardly go through a single day without noticing or hearing what the temperature is. Believe it or not, considerable controversy exists among some scientists as to what the…
Density and Specific Gravity
In ancient times, counterfeit gold objects were identified by comparing the ratio of the weight to the volume of water displaced by the object, which is a way to measure…
The Mole and Molecular Weight
What is a mole? For our purposes we will say that a mole is a certain amount of material corresponding to a specified number of molecules, atoms, electrons, or other…
