Chemistry

Inorganic chemistry is based around a huge array of elements, many of which are metals and some of which we are all familiar with. For example iron (Fe), copper (Cu), zinc (Zn), silver (Ag), calcium (Ca), sodium (Na) etc.

The non metals chlorine (C1), iodine (I), sulphur (S), nitrogen (N), oxygen (0) etc. combine with metals to form „salts“.

The most common to most of us is table salt or sodium chloride – NaCl, which of course forms a significant part of sea water. There is approximately 3% or 30,000ppm of sodium chloride in typical sea water as well as many other minerals and salts in smaller concentrations.

For the purpose of this tank cleaning guide Inorganic Chemistry is less important. The vast majority of the cargoes transported on tankers vessels are ORGANIC in nature.

In comparison to inorganic chemistry the number of chemical elements involved in this branch of chemistry is very few, and is in fact largely centred on only two elements:
carbon (C) and hydrogen (H) and some oxygen, nitrogen or sulphur to make it more interesting.
Even though one can narrow down the bulk of organic chemistry to just a handful of elements the range of compounds that can be made from these elements is absolutely enormous!
Apart from mineral acids almost all bulk liquid cargoes are organic compounds, from petroleum products to solvents to vegetable oils to Vodka!
So just what is organic chemistry?

In chemistry, a homologous series is a series of organic compounds with a similar general formula, possessing similar chemical properties due to the presence of the same functional group, and shows a gradation in physical properties as a result of increase in molecular size and mass (see relative molecular mass). For example, ethane has a higher boiling point than methane since it has more intermolecular forces with neighbouring molecules. This is due to the increase in the number of atoms making up the molecule. Organic compounds in the same homologous series vary by a CH2.

Alkanes (paraffins), alkenes (olefins), ethers, and alkynes (acetylenes) form such series in which members differ in mass by 14 atomic mass units. For example, the alkane homologous series begins with methane (CH4), ethane (C2H6), propane (C3H8), butane (C4H10), and pentane (C5H12), each member differing from the previous one by a CH2 group (or 14 atomic mass units).

Similarly, there is the alcohol homologous series that starts with methanol (CH4O), ethanol (C2H6O), as primary alcohols, isopropanol (C3H8O) as a simple secondary alcohol, and a simple tertiary alcohol is tert-butanol (C4H10O).

Even though the general formula remains constant in a homologous series, specific members of the series may have different structures or entirely different properties, though qualitatively, reactivity usually remains the same. Compounds in each series typically have a similar group of atoms called a functional group. Most chemical properties of organic compounds are due to the presence of functional groups.