First thing first, we need to know on how to write the general formula. General formula can be divide into two which molecular formula or emprical formula. Molecular formula is the actual number of atoms represent in a molecule.For example, butene C4H8. While, emprical formula is the simplest ratio of atoms in a molecule. For example butene, instead of write as C4H8 we need to write as CH2.
structural formula can be divide into 3 which are expanded structure, condensed structure and skeletal structure. Expanded structure shows every atoms in a molecule.
Condensed structure shows all atoms, but omits some or all of the verticle and horinzontal bonds. it makes it easier to write the formula in a line.
The last structural formula is skeletal structure it shows just the carbon skeleton and the functional group. it does not need to shows carbon atoms and hydrogen atoms that attached directly to carbon atoms.
There are three structural isomers which chain, position and functional group. All of them have same chemical properties but different physical properties.
Chain can be represent as linear or branch. both of them has similar number of atoms but different arrangement that make them be a different molecule.
Next, position of the functional group that be added at the different side also make them be a different molecule.
Last structural isomers is functional group, the different functional group added to the molecule will form different molecule even though total of each atoms are equally.
Stereoisomerism, include geometrical isomers and optical isomers. Geometrical isomers have cis- isomers and trans-isomers. the different between this two isomer just the arrangement of same functional group. cis-isomers will have same functional group in adjacent. while trans- isomers will have the same functional group in opposite site.
Optical isomers has two characteristic which are stereoisomer not superimposible and not mirror image. Chiral carbon is a carbon that has four different functional group attaches to itself. From this optical isomers, we can know how many isomer presence by 2n , n is represent how many chiral carbon in a molecule.
Alkanes soluble in non polar solvent but insoluble in water. the boiling point of alkanes will increase as the number of carbon in a molecule increase. Besides, boiling point of alkanes in the form of branch more higher compare to the linear arrangement. For number of carbon from 1 to 4 it in the form of gasses at normal temperature, while carbon 5-18 in the form of liquids, and number of carbon more than 18 in the form of solid.
That's all for this chapter, hope this will help you💕
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