# Introduction to Chemical Engineering Processes/General chemistry review

## Stoichiometry

### Mole

The mole is a measure of the amount of substance. A mole is the amount of material which contains the same number of elementary entities as there are atoms in 12g of Carbon-12.

There are Avogadro number of atoms in 12g of Carbon-12, i.e. 6.023 x 10^23 atoms.

Thus a mole of cars implies there are 6.023 x 10^23 cars and so on.

## Acid-Base

There are two major ways to classify acids and bases: the Brønsted-Lowry definition, and the Lewis definition. A chemical species that donates protons is a Brønsted-Lowry acid, and a species that accepts protons is a Brønsted-Lowry base. Typically, the proton is written as an H+ ion, though they do not in isolation exist in solution and are instead exchanged between molecules. In water, the proton on an acid will often bond to the H2O molecules to form the conjugate base and H3O+ (hydronium) ions, and the proton-accepting base will take an H+ from the water to form the conjugate acid and OH- (hydroxide) ions. This is the most familiar situation for those who have taken general chemistry, but any species that loses an H+ (proton) to another molecule is considered a Brønsted-Lowry acid, and likewise any H+-taking species is considered a Brønsted-Lowry base.

The second and broader classification is the Lewis acids and bases. Lewis acids and bases are defined by their electron lone pair behavior. A Lewis acid is an electron acceptor (called an electrophile in organic chemistry), a Lewis base is an electron donor (a nucleophile in organic chemistry). In a Lewis acid-base reaction, the negatively charged electron lone pair in the base will bond to the positive or partially positive segment of the acid to form what is called a Lewis adduct. Unlike Brønsted-Lowry acids and bases, the exchange of protons is not required.

## Ideal Gas Law

${\displaystyle PV=nRT}$

P = Pressure; V = Volume; n = moles; R = Ideal gas constant; T = Temperature

## Enthalpy

The enthalpy content of a substance is given by

\hat{H} = U + pV

where

H is the enthalpy (SI units: J/kg) U is the internal energy and p is the pressure V is the volume

## Branches of Chemistry

• Inorganic Chemistry - The study of the synthesis and behavior of inorganic and organometallic compounds. This field covers all chemical compounds except the myriad organic compounds.
• Organic Chemistry - The study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.
• Physical Chemistry - The study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of laws and concepts of physics. It applies the principles, practices and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics and dynamics, equilibrium.
• Analytical Chemistry -
• Biochemistry -
• Organometallic chemistry -