Assume each reaction is carried out in a open container. For which reaction Δ H=Δ E ?

Question

Assume each reaction is carried out in a open container. For which reaction Δ H=Δ E ? (A) H 2(g)+ Br 2(g) longrightarrow 2 HBr (g) (B) C ( s )+2 H 2 O (g) longrightarrow 2 H 2(g)+ CO 2(g) (C) PCl 5(g) longrightarrow PCl 3(g)+ Cl 2(g) (D) 2 CO (g)+ O 2(g) longrightarrow 2 CO 2(g)

Tardigrade Admin · Accepted Answer

Δ H=Δ E+p Δ V Δ H=Δ E+Δ n R T open container, therefore Δ H=Δ E So, for the reaction (a). Δ n=2-2=0 Hence, for the reaction, Δ H=Δ E.

Q. Assume each reaction is carried out in a open container. For which reaction $Δ H = Δ E$ ?

$H_{2} (g) + B r_{2} (g) ⟶ 2 H B r (g)$

$C (s) + 2 H_{2} O (g) ⟶ 2 H_{2} (g) + C O_{2} (g)$

$PC l_{5} (g) ⟶ PC l_{3} (g) + C l_{2} (g)$

$2 CO (g) + O_{2} (g) ⟶ 2 C O_{2} (g)$

$Δ H = Δ E + p Δ V$
$Δ H = Δ E + Δ n RT$
open container, therefore $Δ H = Δ E$
So, for the reaction (a). $Δ n = 2 - 2 = 0$
Hence, for the reaction, $Δ H = Δ E$ .

Q. Assume each reaction is carried out in a open container. For which reaction ΔH=ΔE ?

H2​(g)+Br2​(g)⟶2HBr(g)

C(s)+2H2​O(g)⟶2H2​(g)+CO2​(g)

PCl5​(g)⟶PCl3​(g)+Cl2​(g)

2CO(g)+O2​(g)⟶2CO2​(g)