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प्रश्न
What is a homologous series?
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उत्तर
A homologous series is a group of organic compounds having a similar structure and similar chemical properties in which the successive compounds differ by a CH2 group.
Example:
HCOOH - Methanoic acid
CH3COOH - Ethanoic acid
CH3CH2COOH - Propanoic acid
संबंधित प्रश्न
Classify the following carbon compounds into two homologous series and name them.
C3H4, C3H6, C4H6, C4H8, C5H8, C5H10
Write the name and formula of the 2nd member of homologous series having general formula CnH2n.
Write the name and formula of the 2nd member of homologous series having general formula CnH2n – 2.
Write the molecular formula of two consecutive members of homologous series of aldehydes. State which part of these compounds determines their
- physical and
- chemical properties
Complete the following table which relates to the homologous series of hydrocarbons.
| General formulaе | IUPAC name of the homologous series | Characteristic bond type | IUPAC name of the first member of the series |
| CnH2n−2 | (A) ______ | (B) ______ | (C) ______ |
| CnH2n+1 | (B) ______ | (E) ______ | (F) ______ |
Carbon compounds have usually ______ melting points and boiling points because they are ______ in nature.
Succeeding members of a homologous series differ by ______.
.
Cyclohexane : Cyclic hydrocarbon : : Isobutylene : _______
Complete the following table for homologous series of Alkenes.
| Name | Molecular formula | Condensed structural formula | Number of carbon atom | Number of -CH2- units | Boiling point °C |
| Ethene | C2H4 | CH2 = CH2 | 2 | 0 | -102 |
| Propene | C3H6 | CH3–CH = CH2 | 3 | 1 | -48 |
| 1-Butene | C4H8 | CH3–CH2–CH = CH2 | ______ | ______ | -6.5 |
| 1-Pentene | C5H10 | CH3–CH2–CH2–CH = CH2 | ______ | ______ | 30 |
