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Question
Name the third homologue of aldehydes.
Solution
Propanal, which has the chemical formula C3H6O, is an aldehyde's third homologue. Having a carbonyl group (C=O) attached to the second carbon, it consists of a straight chain of three carbon atoms.
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RELATED QUESTIONS
State any four characteristics of a homologous series
Classify the following carbon compounds into two homologous series and name them.
C3H4, C3H6, C4H6, C4H8, C5H8, C5H10
By how many carbon atoms and hydrogen atoms do any two adjacent homologues differ?
What is the difference in the molecular formula of any two adjacent homologues in terms of molecular mass?
Study the different conclusions drawn by students of a class on the basis of observations of preserved/available specimens of plants and animals.
I. Potato and sweet potato are analogous organs in plants.
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IV. Thorns of citrus and tendrils of cucurbita are analogous organs in plants.
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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 |
Name and draw the electron dot structure of first homologue of alkynes series.
