(a) Explain the term 'isomers'. Give one example of isomers.
(b) Write (i) structural formula, and (ii) electron-dot structure, of any one isomer of n-heptane (C7H16).
(c) Write IUPAC name of the compound having the formula n−C4H10.
(d) Give the IUPAC names for the following :
(a) Explain the term 'isomers'. Give one example of isomers.
(b) Write (i) structural formula, and (ii) electron-dot structure, of any one isomer of n-heptane (C7H16).
(c) Write IUPAC name of the compound having the formula n−C4H10.
(d) Give the IUPAC names for the following :
(a) Isomers: Isomers are compounds with the same molecular formula but different arrangements of carbon atoms in them. The existence of two or more organic compounds with the same molecular formula but a different arrangement of carbon atoms is called isomerism. Isomerism can only exist in hydrocarbons comprising 4 or more carbon atoms.
An example of an isomer is the compound Butane (C4H10). As the number of carbon atoms is four, two isomers of butane are possible, and they are n-butane (normal butane with a straight chain arrangement) and iso-butane (three carbon atoms put in a straight chain, and the fourth carbon atom is joined in the side chain to form a different structure).
The structural formula for the isomers of butane are as follows:
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(b) (i) Heptane (C7H16) has 7 carbon atoms in its molecule. An isomer other than n-heptane will be 2-methyl hexane. The structural formula is shown below :
_i.png)
(ii) The electronic dot structure is as follows:
_ii.png)
(c) The IUPAC name of n−C4H10 is butane.
This is because the compound is a saturated hydrocarbon and has 4 carbon atoms in its molecule. If it has four carbon atoms in a single chain, it is represented by the word "but", and as it comprises all single bonds, it is represented by the ending "ane". Again, as the carbon atoms are in a single continuous chain, it is represented by n-Butane (where n is normal).
(d) (i) 2-methyl propane
(ii) 2-methyl butane
(iii) Propene
(iv) Propyne
(a) Isomers: Isomers are compounds with the same molecular formula but different arrangements of carbon atoms in them. The existence of two or more organic compounds with the same molecular formula but a different arrangement of carbon atoms is called isomerism. Isomerism can only exist in hydrocarbons comprising 4 or more carbon atoms.
An example of an isomer is the compound Butane (C4H10). As the number of carbon atoms is four, two isomers of butane are possible, and they are n-butane (normal butane with a straight chain arrangement) and iso-butane (three carbon atoms put in a straight chain, and the fourth carbon atom is joined in the side chain to form a different structure).
The structural formula for the isomers of butane are as follows:
(b) (i) Heptane (C7H16) has 7 carbon atoms in its molecule. An isomer other than n-heptane will be 2-methyl hexane. The structural formula is shown below :
(ii) The electronic dot structure is as follows:
(c) The IUPAC name of n−C4H10 is butane.
This is because the compound is a saturated hydrocarbon and has 4 carbon atoms in its molecule. If it has four carbon atoms in a single chain, it is represented by the word "but", and as it comprises all single bonds, it is represented by the ending "ane". Again, as the carbon atoms are in a single continuous chain, it is represented by n-Butane (where n is normal).
(d) (i) 2-methyl propane
(ii) 2-methyl butane
(iii) Propene
(iv) Propyne
