In the complete combustion of butanol textC text4 textH text9 textOH(I) if text ! !Δ ! ! text H is enthalpy of combustion and text ! !Δ ! ! text E is the heat of combustion at constant volume, then:

Question

In the complete combustion of butanol textC text4 textH text9 textOH(I) if text ! !Δ ! ! text H is enthalpy of combustion and text ! !Δ ! ! text E is the heat of combustion at constant volume, then: (A)  Δ H <Δ E  (B)  Δ H =Δ E  (C)  Δ H >Δ E  (D)  Δ H ,Δ E relation cannot to be predicted

Tardigrade Admin · Accepted Answer

Combustion reaction of butanol is: C4H9OH+6O2 xrightarrow4CO2+5H2O Total no. of moles product = 4 + 5 = 9 Total no. of moles reactant =1+ 6 = 7 Δ n= number of moles of products - number of moles of reactants = 9 - 7 = 2means that Δ n have +ve value. From the equation Δ H=Δ E+Δ n RT If Δ n= 0 then Δ H =Δ E If Δ n= -ve then Δ H<Δ E If Δ n=+ve then Δ H>Δ E In the question Δ n has +ve value so, AH>AE. Δ H>Δ E.

Q. In the complete combustion of butanol $C_{4} H_{9} OH(I)$ if $Δ H$ is enthalpy of combustion and $Δ E$ is the heat of combustion at constant volume, then:

$Δ H < Δ E$

$Δ H = Δ E$

$Δ H > Δ E$

$Δ H, Δ E$ relation cannot to be predicted

Q. In the complete combustion of butanol C4​H9​OH(I) if Δ H is enthalpy of combustion and Δ E is the heat of combustion at constant volume, then:

ΔH<ΔE

ΔH=ΔE

ΔH>ΔE

ΔH,ΔE relation cannot to be predicted

Q. In the complete combustion of butanol $C_{4} H_{9} OH(I)$ if $Δ H$ is enthalpy of combustion and $Δ E$ is the heat of combustion at constant volume, then:

$Δ H < Δ E$

$Δ H = Δ E$

$Δ H > Δ E$

$Δ H, Δ E$ relation cannot to be predicted