Question

An alkene ‘A’ contains three C – C, eight C – H σ bonds and one C – C \(\pi\) bond. ‘A’ on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write IUPAC name of ‘A’.

Answer 1

Given:

• Number of C–C σ bonds = 3
• Number of C–H σ bonds = 8
• Number of C–C π bonds = 1
• On ozonolysis, gives two moles of an aldehyde
• Molar mass of aldehyde = 44 u

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Step 1: Identify the aldehyde

An aldehyde with molar mass 44 u is ethanal (CH₃CHO).

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Step 2: Interpret ozonolysis result

Ozonolysis splits the C=C bond of an alkene into carbonyl compounds. Getting two identical molecules of ethanal indicates that the alkene is symmetrical.

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Step 3: Determine the alkene structure

The alkene which on ozonolysis gives two molecules of ethanal is:

CH₃–CH = CH–CH₃

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Step 4: Verify bond count

C–C σ bonds = 3
C–H σ bonds = 8
C–C π bond = 1

All given conditions are satisfied.

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Final Answer:

The IUPAC name of alkene A is but-2-ene.