The order of stability of the alkenes
`underset(I)(R_(2)C=CR_(2)') underset(II)(R_(2)C=CHE) underset(III)(R_(2)C=CH_(2)')underset(IV)(RCH=CHR,) "and" underset(V)(RCH=CH_(2))`
is -

Options

A. `I gt II gt III gt IV gt V`
B. `I = II gt III gt IV gt V`
C. `II gt I gt IV gt III gt V`
D. `V gt IV gt III gt II gt I`

Answer

To determine the order of stability of the given alkenes, we need to analyze the degree of substitution of each alkene. The stability of alkenes is influenced by the number of alkyl groups attached to the carbon atoms involved in the double bond. More substituted alkenes are generally more stable due to hyperconjugation and the inductive effect of alkyl groups.

Let's analyze each option:

1. **(I) R₂C=CR₂'**: This alkene has two alkyl groups on each carbon of the double bond, making it a tetrasubstituted alkene. This is the most stable configuration.

2. **(II) R₂C=CHE**: This alkene has two alkyl groups on one carbon and one hydrogen on the other carbon, making it a trisubstituted alkene. This is less stable than the tetrasubstituted alkene.

3. **(III) R₂C=CH₂'**: This alkene has two alkyl groups on one carbon and two hydrogens on the other carbon, making it a disubstituted alkene. This is less stable than the trisubstituted alkene.

4. **(IV) RCH=CHR**: This alkene has one alkyl group on each carbon of the double bond, making it a disubstituted alkene as well. Its stability is similar to that of (III).

5. **(V) RCH=CH₂**: This alkene has one alkyl group on one carbon and two hydrogens on the other carbon, making it a monosubstituted alkene. This is the least stable configuration.

Now, we can summarize the order of stability based on the degree of substitution:

**Order of Stability:**
1. (I) R₂C=CR₂' (Tetrasubstituted)
2. (II) R₂C=CHE (Trisubstituted)
3. (III) R₂C=CH₂' (Disubstituted)
4. (IV) RCH=CHR (Disubstituted)
5. (V) RCH=CH₂ (Monosubstituted)

Thus, the final order of stability is:
**I > II > III = IV > V**