Question

What is the condensed structural formula for 2, 2 – dimethylbutane?

Answer 1

A condensed structural formula is different from a structural formula. It is more compact and easier to write. It consists of the general formula, but the atoms are placed in a manner that depicts the structural position of the atoms. Condensed form also tells the nature of bonds.

Complete answer:
The condensed formulas of molecules are convenient to study and easy to write in compact spaces. The condensed structural formula for compounds are different from the chemical or molecular formula, as they consist of the atoms according to their positions with the representation of double or triple bonds as in the structural formula, while molecular formula tells the total number of atoms present in the molecule without telling us the positions of atoms.
2,2 – dimethylbutane is a type of alkane that has 4 carbon atoms as identified by the butane. Apart from 4 carbon atoms, it consists of 2 methyl groups at the second carbon atom. So, it is written as 2,2 – dimethylbutane.
For writing its condensed structural formula we will first write the 4 carbons and then beside the second carbon atom we will write the methyl groups in brackets which are 2 in number that would indicate branching of dimethyl, and then we will write the hydrogen atoms according to the carbon positions. Therefore the condensed structural formula will be,
$C{{H}_{3}}C{{(C{{H}_{3}})}_{2}}C{{H}_{2}}C{{H}_{3}}$, the methyl group in the brackets is after the carbon to which they are attached, which is the 2nd carbon atom.
Hence, the condensed structural formula for 2, 2 – dimethylbutane is $C{{H}_{3}}C{{(C{{H}_{3}})}_{2}}C{{H}_{2}}C{{H}_{3}}$

Note:
Through condensed structural formulas we can easily draw the structural formula of any molecule. The molecular formula is different as it tells the exact atoms present in any compound, it does not tell the branching or any other functional group present. The molecular formula for this compound will be ${{C}_{4}}{{H}_{14}}$.