Choose the reaction with negative Δ S value.

Question

Choose the reaction with negative Δ S value. (A) 2 NaHCO 3( s ) arrow Na 2 CO 3( s )+ CO 2( g )+ H 2 O ( g ) (B) Cl 2 (g) arrow 2 Cl ( g ) (C) 2 SO 2( g )+ O 2( g ) arrow 2 SO 3( g ) (D) 2 KClO 3( s ) arrow 2 KCl ( s )+3 O 2( g )

Tardigrade Admin · Accepted Answer

Δ S has negative value if number of gaseous moles decreases during a reaction, Δ ng=- ve For the reaction 2 SO 2+ O 2 longrightarrow 2 SO 3 Δ ng=2-3=-1

Q. Choose the reaction with negative $Δ S$ value.

$2 N a H C O_{3} (s) \to N a_{2} C O_{3} (s) + C O_{2} (g) + H_{2} O (g)$

$C l_{2} (g) \to 2 Cl (g)$

$2 S O_{2} (g) + O_{2} (g) \to 2 S O_{3} (g)$

$2 K Cl O_{3} (s) \to 2 K Cl (s) + 3 O_{2} (g)$

$Δ S$ has negative value if number of gaseous moles decreases during a reaction, $Δ n_{g} = -$ ve
For the reaction
$2 S O_{2} + O_{2} ⟶ 2 S O_{3}$
$Δ n_{g} = 2 - 3 = - 1$

Q. Choose the reaction with negative ΔS value.

2NaHCO3​(s)→Na2​CO3​(s)+CO2​(g)+H2​O(g)

Cl2​(g)→2Cl(g)

2SO2​(g)+O2​(g)→2SO3​(g)

2KClO3​(s)→2KCl(s)+3O2​(g)