Out of the following compounds, I.Pent-1-ene, II.Pent-2-ene, III.2-Methyl but-1-ene, IV.2-Methyl but-2-ene, Which pair has the lowest and the highest heats of combustion, respectively?

Question

Out of the following compounds, I.Pent-1-ene, II.Pent-2-ene, III.2-Methyl but-1-ene, IV.2-Methyl but-2-ene, Which pair has the lowest and the highest heats of combustion, respectively? (A) (IV) and (I),respectively (B) (I) and(IV), respectively (C) (II) and (III), respectively (D) (III) and (II), respectively

Tardigrade Admin · Accepted Answer

More-stable or more-substituted alkene has the lowest (more negative)

Δ H_{C}^{\circ}, Δ H_{formation}

, and

Δ H^{\circ}_{h}

. The order of stability of alkene
:IV

>

III

>

II

>

I.So the lowest

Δ H_{C}^{\circ}

is of (IV) and the highest is of (I)

Q. Out of the following compounds, I.Pent-1-ene, II.Pent-2-ene, III.2-Methyl but-1-ene, IV.2-Methyl but-2-ene, Which pair has the lowest and the highest heats of combustion, respectively?

(IV) and (I),respectively

(I) and(IV), respectively

(II) and (III), respectively

(III) and (II), respectively

More-stable or more-substituted alkene has the lowest (more negative) ΔHC∘​,ΔHformation ​, and ΔH∘h​. The order of stability of alkene :IV > III > II > I.So the lowest ΔHC∘​ is of (IV) and the highest is of (I)

Q. Out of the following compounds,
I.Pent-1-ene,
II.Pent-2-ene,
III.2-Methyl but-1-ene,
IV.2-Methyl but-2-ene,
Which pair has the lowest and the highest heats of combustion, respectively?

More-stable or more-substituted alkene has the lowest (more negative) $Δ H_{C}^{\circ}, Δ H_{formation}$ , and $Δ H^{\circ}_{h}$ . The order of stability of alkene
:IV $>$ III $>$ II $>$ I.So the lowest $Δ H_{C}^{\circ}$ is of (IV) and the highest is of (I)