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H2S + 2HNO3 → S + N2O4 + 2H2O

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Reaction of hydrogen sulfide and nitric acid
H2SHydrogen sulfide + 2HNO3Nitric acid
⟶
SSulfur + N2O4Dinitrogen tetraoxide + 2H2OWater

The reaction of hydrogen sulfide and nitric acid yields sulfur, dinitrogen tetraoxide, and water (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:

Table of contents
  1. 1Reaction data
  2. 2Thermodynamic changes
  3. 3References
  4. 4Related reactions
  5. 5Related categories

Reaction data

Chemical equation

Reaction of hydrogen sulfide and nitric acid
H2SHydrogen sulfide + 2HNO3Nitric acid
⟶
SSulfur + N2O4Dinitrogen tetraoxide + 2H2OWater

General equation

Reaction of reducing species and oxidizing species
Reducing speciesReducing agent + Oxidizing speciesOxidizing agent
⟶
ProductOxidation product + ProductReduction product

Oxidation state of each atom

Reaction of hydrogen sulfide and nitric acid

Reactants

Chemical formulaNameCoefficientTypeType in general
equation
H2SHydrogen sulfide1
Reducing
Reducing
HNO3Nitric acid2
Oxidizing
Oxidizing

Products

Chemical formulaNameCoefficientTypeType in general
equation
SSulfur1
Oxidized
–
N2O4Dinitrogen tetraoxide1
Reduced
–
H2OWater2
–
–

Thermodynamic changes

Changes in standard condition (1)

Reaction of hydrogen sulfide and nitric acid
◆
ΔrG−181.74 kJ/mol
K6.91 × 1031
pK−31.84
H2SGas + 2HNO3Liquid
⟶
SCrystalline solidrhombic + N2O4Liquid + 2H2OLiquid
Standard enthalpy
of reaction
ΔrH°
kJ · mol−1		Standard
Gibbs energy
of reaction
ΔrG°
kJ · mol−1		Standard entropy
of reaction
ΔrS°
J · K−1 · mol−1		Standard heat
capacity of reaction
at constant pressure
ΔrCp°
J · K−1 · mol−1
per 1 mol of
Equation
−222.33−181.74−136.262.0
per 1 mol of
−222.33−181.74−136.262.0
per 1 mol of
−111.17−90.870−68.1031.0
per 1 mol of
−222.33−181.74−136.262.0
−222.33−181.74−136.262.0
per 1 mol of
−111.17−90.870−68.1031.0

Changes in standard condition (2)

Reaction of hydrogen sulfide and nitric acid
H2SGas + 2HNO3Liquid
⟶
SCrystalline solidmonoclinic + N2O4Liquid + 2H2OLiquid
Standard enthalpy
of reaction
ΔrH°
kJ · mol−1		Standard
Gibbs energy
of reaction
ΔrG°
kJ · mol−1		Standard entropy
of reaction
ΔrS°
J · K−1 · mol−1		Standard heat
capacity of reaction
at constant pressure
ΔrCp°
J · K−1 · mol−1
per 1 mol of
Equation
−222.00–––
per 1 mol of
−222.00–––
per 1 mol of
−111.00–––
per 1 mol of
−222.00–––
−222.00–––
per 1 mol of
−111.00–––

Changes in aqueous solution

Reaction of hydrogen sulfide and nitric acid
◆
ΔrG−126.39 kJ/mol
K1.39 × 1022
pK−22.14
H2SUn-ionized aqueous solution + 2HNO3Ionized aqueous solution
⟶
SCrystalline solidrhombic + N2O4Liquid + 2H2OLiquid
Standard enthalpy
of reaction
ΔrH°
kJ · mol−1		Standard
Gibbs energy
of reaction
ΔrG°
kJ · mol−1		Standard entropy
of reaction
ΔrS°
J · K−1 · mol−1		Standard heat
capacity of reaction
at constant pressure
ΔrCp°
J · K−1 · mol−1
per 1 mol of
Equation
−136.7−126.39−33–
per 1 mol of
−136.7−126.39−33–
per 1 mol of
−68.35−63.195−17–
per 1 mol of
−136.7−126.39−33–
−136.7−126.39−33–
per 1 mol of
−68.35−63.195−17–

Thermodynamic data of reactants

Chemical formulaStandard enthalpy
of formation
ΔfH°
kJ · mol−1		Standard Gibbs
energy of
formation
ΔfG°
kJ · mol−1		Standard
molar entropy
S°
J · K−1 · mol−1		Standard molar
heat capacity at
constant pressure
Cp°
J · K−1 · mol−1
H2S (g)-20.63[1]-33.56[1]205.79[1]34.23[1]
H2S (ao)-39.7[1]-27.83[1]121[1]–
HNO3 (l)-174.10[1]-80.71[1]155.60[1]109.87[1]
HNO3 (g)-135.06[1]-74.72[1]266.38[1]53.35[1]
HNO3 (ai)-207.36[1]-111.25[1]146.4[1]-86.6[1]
HNO3 (l)
1 hydrate
-473.46[1]-328.77[1]216.90[1]182.46[1]
HNO3 (l)
3 hydrate
-1056.04[1]-811.09[1]346.98[1]325.14[1]
* (g):Gas, (ao):Un-ionized aqueous solution, (l):Liquid, (ai):Ionized aqueous solution

Thermodynamic data of products

Chemical formulaStandard enthalpy
of formation
ΔfH°
kJ · mol−1		Standard Gibbs
energy of
formation
ΔfG°
kJ · mol−1		Standard
molar entropy
S°
J · K−1 · mol−1		Standard molar
heat capacity at
constant pressure
Cp°
J · K−1 · mol−1
S (cr)
rhombic
0[1]0[1]31.80[1]22.64[1]
S (cr)
monoclinic
0.33[1]–––
S (g)278.805[1]238.250[1]167.821[1]23.673[1]
N2O4 (l)-19.50[1]97.54[1]209.2[1]142.7[1]
N2O4 (g)9.16[1]97.89[1]304.29[1]77.28[1]
H2O (cr)––––
H2O (l)-285.830[1]-237.129[1]69.91[1]75.291[1]
H2O (g)-241.818[1]-228.572[1]188.825[1]33.577[1]
* (cr):Crystalline solid, (g):Gas, (l):Liquid

References

List of references

  1. 1
    Janiel J. Reed (1989)
    The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI Units
    National Institute of Standards and Technology (NIST)