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प्रश्न
Assertion (A): In a homologous series of alcohols, the formula for the second member is C2H5OH and the third member is C3H7OH.
Reason (R): The difference between the molecular masses of the two consecutive members of a homologous series is 144.
विकल्प
Both A and R are true and R is the correct explanation of the Assertion.
Both A and R are true but R is not the correct explanation of the Assertion.
A is true but R is false.
A is false but R is true.
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उत्तर
A is true but R is false.
Explanation:
In a homologous series of alcohols, the formula for the second member is C2H5OH and the third member is C3H7OH. The difference between the molecular masses of the two consecutive members of a homologous series is 14.
Hence, the correct answer is the assertion is true and Reason is false.
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संबंधित प्रश्न
Classify the following carbon compounds into two homologous series and name them.
C3H4, C3H6, C4H6, C4H8, C5H8, C5H10
Give the structural formula for 1, 2-dichloroethane
The molecular formula of an organic compound is C18H36. Name its homologous series.
The molecular formula of a homologue of butane is:
(a) C4H8
(b) C3H6
(c) C4H6
(d) C3H8
An organic compound having the molecular formula C3H6O can exist in the form of two isomers A and B having different functional groups. The isomer A is a liquid which is used as a solvent for nail polish. The isomer B is also a liquid. An aqueous solution of one of the lower homologues of B is used for preserving biological specimens in the laboratory
(a) What is compound A?
(b) Write the electron-dot structure of A.
(c) What is compound B?
(d) Write the electron-dot structure of B.
(e) Name the lower homologue of compound B which is used in preserving biological specimens.
Give the dot diagram of the first member of the alcohol.
What is homologous series ?
Why homologous series of carbon compounds are so called? Write chemical formula of two consecutive members of a homologous series and state the part of these compounds that determines their (i) physical properties, and (ii) chemical properties.
Complete the following table for homologous series of alcohols.
| Name | Molecular formula | Condensed structural formula | Number of carbon atom | Number of -CH2- units | Boiling point °C |
| Methanol | CH4O | CH3-OH | 1 | 1 | 63 |
| Ethanol | C2H6O | CH3–CH2-OH | 2 | 2 | 78 |
| Propanol | C3H8O | CH3–CH2–CH2-OH | ______ | ______ | 97 |
| Butanol | C4H10O | CH3–CH2–CH2–CH2–OH | ______ | ______ | 118 |
A carbon compound ‘A’ having melting point 156K and boiling point 351K, with molecular formula C2H6O is soluble in water in all proportions.
- Identify ‘A’ and draw its electron dot structure.
- Give the molecular formulae of any two homologues of ‘A’.
