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प्रश्न
The general molecular formula for the homologous series of alkynes is _______.
विकल्प
CnH2n
`"C"_"n""H"_("2n" + 2)`
`"C"_"n""H"_("2n" - 2)`
`"C"_"n""H"_("2n" - 1)`
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उत्तर
The general molecular formula for the homologous series of alkynes is `underline("C"_"n""H"_("2n" - 2))`.
संबंधित प्रश्न
State any four characteristics of a homologous series
Write the next homologue of the following: C2H4
Write the next homologue of the following: C4H6
Write the name and formula of the 2nd member of homologous series having general formula CnH2n + 2.
Write the name and formula of the 2nd member of homologous series having general formula CnH2n – 2.
What is a homologous series? Explain with an example.
The molecular formula of the third member of the homologous series of ketones is:
(a) C4H8O
(b) C3H6O
(c) C5H10O
(d) C6H12O
Write the name and molecular formula of the first member of the homologous series of alkynes.
Distinguish between homologous organs and analogous organs. In which category would you place wings of a bird and wings of a bat? Justify your answer giving a suitable reason.
Copy and complete the following table, which relates to the three homologous series of hydrocarbons:
| General formula | CnH2n | CnH2n-2 | CnH2n+2 |
| IUPAC name of the homologus series | |||
| Characteristic bond type | Single bonds | ||
| IUPAC name of the first member of the series | |||
| Type of reaction with chlorine | Addition |
What is the difference in the molecular formula of any two adjacent homologues:
(i) In terms of molecular mass
(ii) In terms of number and kind of atoms per molecule?
The unsaturated hydrocarbons containing a carbon-carbon double bond are called _______.
Write a short note.
Homologous series
Complete the following table for the homologous series of alkanes.
| Name | Molecular formula | Condensed structural formula | Number of carbon atom | Number of -CH2- units | Boiling point °C |
| Methane | CH4 | CH4 | 1 | 1 | -162 |
| Ethane | C2H6 | CH3–CH3 | 2 | 2 | -88.5 |
| Propane | C3H8 | CH3–CH2–CH3 | 3 | 3 | -42 |
| Butane | C4H10 | CH3–CH2–CH2–CH3 | ______ | ______ | 0 |
| Pentane | C5H12 | CH3–CH2–CH2–CH2–CH3 | ______ | ______ | 36 |
| Hexane | C6H14 | CH3–CH2–CH2–CH2–CH2–CH3 | ______ | ______ | 69 |
Complete the following chart by using examples given in brackets.
(isobutylene, cyclohexane, propane, cyclohexene, cyclopentane, benzene, propyne, isobutane, propene)
| Straight chain hydrocarbons | Branched chain hydrocarbons | Cyclic hydrocarbons |
Which of the following does not belong to the same homologous series?
Name the following organic compound:
The first homologue whose general formula is CnH2n.
Study and complete the following table:
| Homologous series | Alkane | Alkyne |
| General formula | CnH2n+2 | 1. ______ |
| IUPAC name | 2. ______ | Ethyne |
| Common name | Marsh gas | 3. ______ |
Consider the following molecular formulae of carbon compounds:
(i) CH3COOH (ii) CH3OH (iii) C2H6 (iv) C3H4 (v) C4H8
- Which one of these compounds belongs to homologous series of alcohols?
- Identify the compound having triple bond between carbon-carbon atoms.
- Write the molecular formula of the first member of the homologous series to which CH3COOH belongs.
- Write the general formula of the series to which the compound C4H8 belongs.
