Solid Ca ( HCO 3)2 decomposes as Ca ( HCO 3)2( s ) leftharpoons CaCO 3( s )+ CO 2( g )+ H 2 O ( g ) if the total pressure is 0.2 bar at 420 K, what is the standard free energy change for the given reaction (Δr G°) ?

Question

Solid Ca ( HCO 3)2 decomposes as Ca ( HCO 3)2( s ) leftharpoons CaCO 3( s )+ CO 2( g )+ H 2 O ( g ) if the total pressure is 0.2 bar at 420 K, what is the standard free energy change for the given reaction (Δr G°) ? (A) 840 kJ / mol (B) 3.86 kJ / mol (C) 6.98 kJ / mol (D) 16.083 kJ / mol

Tardigrade Admin · Accepted Answer

P text total =0.2 bar At equilibrium P CO 2=P H 2 O =0.1 bar KP=(0.1)2=0.01 Δr G°=-R T ln KP =-8.314 × 420 ln (0.01) =16.083 kJ / mol

Q. Solid $C a (H C O_{3})_{2}$ decomposes as
$C a (H C O_{3})_{2} (s) ⇌ C a C O_{3} (s) + C O_{2} (g) + H_{2} O (g)$
if the total pressure is $0.2$ bar at $420 K$ , what is the standard free energy change for the given reaction $(Δ_{r} G^{\circ})$ ?

$840 k J / m o l$

$3.86 k J / m o l$

$6.98 k J / m o l$

$16.083 k J / m o l$

$P_{total} = 0.2$ bar
At equilibrium
$P_{C O_{2}} = P_{H_{2} O} = 0.1 ba r$
$K_{P} = (0.1)^{2} = 0.01$
$Δ_{r} G^{\circ} = - RT ln K_{P}$
$= - 8.314 \times 420 ln (0.01)$
$= 16.083 k J / m o l$

Q. Solid Ca(HCO3​)2​ decomposes as Ca(HCO3​)2​(s)⇌CaCO3​(s)+CO2​(g)+H2​O(g) if the total pressure is 0.2 bar at 420K, what is the standard free energy change for the given reaction (Δr​G∘) ?

840kJ/mol

3.86kJ/mol

6.98kJ/mol

16.083kJ/mol