You-iggy
  1. Home
  2. Chemical reactions
  3. 8HCN + 12HNO3 → 5N2H4 + 10NO2↑ + 8CO2↑

8HCN + 12HNO3 → 5N2H4 + 10NO2↑ + 8CO2↑

Last updated:
Reaction of hydrogen cyanide and nitric acid
8HCNHydrogen cyanide + 12HNO3Nitric acid
⟶
5N2H4Hydrazine + 10NO2↑Nitrogen dioxide + 8CO2↑Carbon dioxide

The reaction of hydrogen cyanide and nitric acid yields hydrazine, nitrogen dioxide, and carbon dioxide (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 cyanide and nitric acid
8HCNHydrogen cyanide + 12HNO3Nitric acid
⟶
5N2H4Hydrazine + 10NO2↑Nitrogen dioxide + 8CO2↑Carbon dioxide

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 cyanide and nitric acid

Reactants

Chemical formulaNameCoefficientTypeType in general
equation
HCNHydrogen cyanide8
Reducing
Reducing
HNO3Nitric acid12
Oxidizing
Oxidizing

Products

Chemical formulaNameCoefficientTypeType in general
equation
N2H4Hydrazine5
Redoxed product
–
NO2Nitrogen dioxide10
Reduced
–
CO2Carbon dioxide8
Oxidized
–

Thermodynamic changes

Changes in standard condition

Reaction of hydrogen cyanide and nitric acid
◆
ΔrG−1926.31 kJ/mol
K2.98 × 10337
pK−337.47
8HCNLiquid + 12HNO3Liquid
⟶
5N2H4Liquid + 10NO2↑Gas + 8CO2↑Gas
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
−1344.88−1926.311946.65−720.25
per 1 mol of
−168.110−240.789243.331−90.031
per 1 mol of
−112.073−160.526162.221−60.021
per 1 mol of
−268.976−385.262389.330−144.05
per 1 mol of
−134.488−192.631194.665−72.025
per 1 mol of
−168.110−240.789243.331−90.031

Changes in aqueous solution (1)

Reaction of hydrogen cyanide and nitric acid
◆
ΔrG−2045.5 kJ/mol
K2.27 × 10358
pK−358.36
8HCNIonized aqueous solution + 12HNO3Ionized aqueous solution
⟶
5N2H4Un-ionized aqueous solution + 10NO2↑Gas + 8CO2↑Gas
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
−1361.2−2045.52291–
per 1 mol of
−170.15−255.69286.4–
per 1 mol of
−113.43−170.46190.9–
per 1 mol of
−272.24−409.10458.2–
per 1 mol of
−136.12−204.55229.1–
per 1 mol of
−170.15−255.69286.4–

Changes in aqueous solution (2)

Reaction of hydrogen cyanide and nitric acid
◆
ΔrG−1978.4 kJ/mol
K3.99 × 10346
pK−346.60
8HCNIonized aqueous solution + 12HNO3Ionized aqueous solution
⟶
5N2H4Un-ionized aqueous solution + 10NO2↑Gas + 8CO2↑Un-ionized aqueous solution
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
−1523.5−1978.41522–
per 1 mol of
−190.44−247.30190.3–
per 1 mol of
−126.96−164.87126.8–
per 1 mol of
−304.70−395.68304.4–
per 1 mol of
−152.35−197.84152.2–
per 1 mol of
−190.44−247.30190.3–

Changes in aqueous solution (3)

Reaction of hydrogen cyanide and nitric acid
◆
ΔrG−1623.9 kJ/mol
K3.13 × 10284
pK−284.49
8HCNUn-ionized aqueous solution + 12HNO3Ionized aqueous solution
⟶
5N2H4Un-ionized aqueous solution + 10NO2↑Gas + 8CO2↑Gas
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
−1013.2−1623.92046–
per 1 mol of
−126.65−202.99255.8–
per 1 mol of
−84.433−135.33170.5–
per 1 mol of
−202.64−324.78409.2–
per 1 mol of
−101.32−162.39204.6–
per 1 mol of
−126.65−202.99255.8–

Changes in aqueous solution (4)

Reaction of hydrogen cyanide and nitric acid
◆
ΔrG−1556.8 kJ/mol
K5.49 × 10272
pK−272.74
8HCNUn-ionized aqueous solution + 12HNO3Ionized aqueous solution
⟶
5N2H4Un-ionized aqueous solution + 10NO2↑Gas + 8CO2↑Un-ionized aqueous solution
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
−1175.5−1556.81277–
per 1 mol of
−146.94−194.60159.6–
per 1 mol of
−97.958−129.73106.4–
per 1 mol of
−235.10−311.36255.4–
per 1 mol of
−117.55−155.68127.7–
per 1 mol of
−146.94−194.60159.6–

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
HCN (l)108.87[1]124.97[1]112.84[1]70.63[1]
HCN (g)135.1[1]124.7[1]201.78[1]35.86[1]
HCN (ai)150.6[1]172.4[1]94.1[1]–
HCN (ao)107.1[1]119.7[1]124.7[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]
* (l):Liquid, (g):Gas, (ai):Ionized aqueous solution, (ao):Un-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
N2H4 (l)50.63[1]149.34[1]121.21[1]98.87[1]
N2H4 (g)95.40[1]159.35[1]238.47[1]49.58[1]
N2H4 (ao)34.31[1]128.1[1]138[1]–
NO2 (g)33.18[1]51.31[1]240.06[1]37.20[1]
CO2 (g)-393.509[1]-394.359[1]213.74[1]37.11[1]
CO2 (ao)-413.80[1]-385.98[1]117.6[1]–
* (l):Liquid, (g):Gas, (ao):Un-ionized aqueous solution

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)