4 HCl (aq) + 1 MnO2 (s) → 2 H2O (ℓ) + MnCl2 (aq) + 1 Cl2 (g)

Back to reactions list

 

Stoichiometry

Enter a mass or volume in one of the boxes below. Upon hitting submit, the stoichiometric equivalents will be calculated for the remaining reactants and products. All gases are assumed to be at STP.

HCl            Mass: g  or Solution Volume: mL of Concentration: mol/L
MnO2           Mass: g
H2O            Mass: g
MnCl2          Mass: g  or Solution Volume: mL of Concentration: mol/L
Cl2            Mass: g  or Gas Volume: L

Enthalpy of Reaction

[2ΔHf(H2O (ℓ)) + 1ΔHf(MnCl2 (aq)) + 1ΔHf(Cl2 (g))] - [4ΔHf(HCl (aq)) + 1ΔHf(MnO2 (s))]
[2(-285.83) + 1(-555.13) + 1(0)] - [4(-167.15) + 1(-520.03)] = 61.8400000000001 kJ
61.84 kJ     (endothermic)

Entropy Change

[2ΔSf(H2O (ℓ)) + 1ΔSf(MnCl2 (aq)) + 1ΔSf(Cl2 (g))] - [4ΔSf(HCl (aq)) + 1ΔSf(MnO2 (s))]
[2(69.91) + 1(39.32) + 1(222.97)] - [4(56.48) + 1(53.05)] = 123.14 J/K
123.14 J/K     (increase in entropy)

Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(H2O (ℓ)) + 1ΔGf(MnCl2 (aq)) + 1ΔGf(Cl2 (g))] - [4ΔGf(HCl (aq)) + 1ΔGf(MnO2 (s))]
[2(-237.18) + 1(-490.53) + 1(0)] - [4(-131.25) + 1(-465.18)] = 25.2900000000001 kJ
25.29 kJ     (nonspontaneous)

From ΔG = ΔH - TΔS:
25.13 kJ     (nonspontaneous)

Equilibrium Constant, K (at 298.15 K)

3.70797806144421E-05
This process is not favorable at 25°C.

Reference(s):

Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 117.
Silberberg, Martin S. Chemistry: The molecular Nature of Matter and Change 4th ed.; McGraw-Hill: Boston, MA, 2006; p 128.

Back to list of reactions