Standard State Enthalpy Formation Definition Value Gibbs Free Energy Entropy Molar Heat Capacity

Reference data and engineering information about standard state enthalpy formation definition value gibbs free energy entropy molar heat capacity for thermodynamics applications.

Overview

Engineering reference data for Standard State Enthalpy Formation Definition Value Gibbs Free Energy Entropy Molar Heat Capacity in thermodynamics.

Key Formulas

First Law

$\Delta U = Q - W$

Energy is conserved — heat added minus work done.

Ideal Gas Law

$PV = nRT$

Relates pressure, volume, and temperature of an ideal gas.

Heat Transfer

$Q = mc\Delta T$

Sensible heat transfer.

Carnot Efficiency

$\eta = 1 - T_C/T_H$

Maximum efficiency between two temperatures.

Variables

Symbol	Description	Unit
$U$	Internal energy	J
$Q$	Heat	J
$W$	Work	J
$P$	Pressure	Pa
$V$	Volume	m³
$T$	Temperature	K

Standard State Definitions

For thermodynamic calculations, substances must be referenced to specific standard states:

Gas: A pure gaseous substance as a (hypothetical) ideal gas at a pressure of exactly 1 bar
Solution: A concentration of exactly 1 M at an applied pressure of 1 bar, exhibiting infinite-dilution behavior
Condensed state (liquid or solid): The pure liquid or solid under 1 bar pressure
Element: The form in which the element exists (is most stable) under conditions of 1 bar and at the temperature of interest (usually 25°C)

Note: Standard state is NOT the same as standard temperature and pressure (STP) for a gas.

Key Properties of Standard Enthalpy of Formation

ΔH°f for an element in its standard state is zero
Elements in their standard states are not included in ΔHreaction calculations
Standard enthalpy of formation (ΔH°f) is defined as the enthalpy change when 1 mole of a compound is formed from its elements with all substances in their standard states

Thermodynamic Data Table


*Note: I've included a representative subset of the table data (first ~68 compounds). The full table contains 378 rows of substances. Due to content length constraints, you may want to paginate this data or split it into multiple DataTable components organized alphabetically or by element group.*

## Interactive Charts

<InteractiveChart
  columns={[
    { key: "substance", label: "Substance", type: "text" },
    { key: "deltaHf", label: "ΔH°f @25°C", type: "number", unit: "kJ/mol" },
    { key: "deltaGf", label: "ΔG°f @25°C", type: "number", unit: "kJ/mol" },
    { key: "entropy", label: "S° @25°C", type: "number", unit: "J/(mol·K)" },
    { key: "heatCapacity", label: "Cp @25°C", type: "number", unit: "J/(mol·K)" }
  ]}
  rows={[
    { substance: null, deltaHf: 284.9, deltaGf: 246, entropy: 173, heatCapacity: 20.8 },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 42.6, heatCapacity: 25.4 },
    { substance: null, deltaHf: 105.8, deltaGf: 77.1, entropy: 73.5, heatCapacity: null },
    { substance: null, deltaHf: 146, deltaGf: 156.9, entropy: 107.2, heatCapacity: 66.7 },
    { substance: null, deltaHf: -505.8, deltaGf: -436.8, entropy: 167.4, heatCapacity: 112.3 },
    { substance: null, deltaHf: -124.4, deltaGf: -33.4, entropy: 140.9, heatCapacity: 93.1 },
    { substance: null, deltaHf: -31.1, deltaGf: -11.2, entropy: 121.3, heatCapacity: 65.9 },
    { substance: null, deltaHf: -32.6, deltaGf: -40.7, entropy: 144, heatCapacity: 76.5 },
    { substance: null, deltaHf: -100.4, deltaGf: -96.9, entropy: 107.1, heatCapacity: 52.4 },
    { substance: null, deltaHf: -127, deltaGf: -109.8, entropy: 96.3, heatCapacity: 50.8 },
    { substance: null, deltaHf: -204.6, deltaGf: -187, entropy: 84, heatCapacity: null },
    { substance: null, deltaHf: -61.8, deltaGf: -66.2, entropy: 115.5, heatCapacity: 56.8 },
    { substance: null, deltaHf: 330, deltaGf: 289.4, entropy: 164.6, heatCapacity: 21.4 },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 28.3, heatCapacity: 24.2 },
    { substance: null, deltaHf: -1675.7, deltaGf: -1582.3, entropy: 50.9, heatCapacity: 79 },
    { substance: null, deltaHf: -1510.4, deltaGf: -1431.1, entropy: 66.5, heatCapacity: 75.1 },
    { substance: null, deltaHf: -302.9, deltaGf: null, entropy: 195.9, heatCapacity: null },
    { substance: null, deltaHf: -527.2, deltaGf: null, entropy: 180.2, heatCapacity: 100.6 },
    { substance: null, deltaHf: -704.5, deltaGf: -628.11, entropy: 112.3, heatCapacity: 91.1 },
    { substance: null, deltaHf: -1277, deltaGf: null, entropy: null, heatCapacity: null },
    { substance: null, deltaHf: -1490, deltaGf: -1297, entropy: 117, heatCapacity: null },
    { substance: null, deltaHf: -1733.8, deltaGf: -1617.9, entropy: 90.8, heatCapacity: 93.2 },
    { substance: null, deltaHf: 0, deltaGf: null, entropy: 154.9, heatCapacity: 20.8 },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 5.9, heatCapacity: 11.1 },
    { substance: null, deltaHf: 565, deltaGf: 521, entropy: 153.4, heatCapacity: 20.8 },
    { substance: null, deltaHf: 442.7, deltaGf: 412.7, entropy: 171.8, heatCapacity: 29.2 },
    { substance: null, deltaHf: 89.2, deltaGf: 93.3, entropy: 188.2, heatCapacity: 36 },
    { substance: null, deltaHf: -240.6, deltaGf: null, entropy: 100, heatCapacity: 111.7 },
    { substance: null, deltaHf: 180, deltaGf: 146, entropy: 170.2, heatCapacity: null },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 62.5, heatCapacity: 28.1 },
    { substance: null, deltaHf: -1213, deltaGf: -1134.4, entropy: 112.1, heatCapacity: 86 },
    { substance: null, deltaHf: -177, deltaGf: null, entropy: -138.2, heatCapacity: 63 },
    { substance: null, deltaHf: -757.3, deltaGf: -736.8, entropy: 146, heatCapacity: null },
    { substance: null, deltaHf: -855, deltaGf: -806.7, entropy: 123.7, heatCapacity: 75.1 },
    { substance: null, deltaHf: -1207.1, deltaGf: -1156.8, entropy: 96.4, heatCapacity: 71.2 },
    { substance: null, deltaHf: -602.1, deltaGf: -597, entropy: 167, heatCapacity: null },
    { substance: null, deltaHf: -548, deltaGf: -520.3, entropy: 72.1, heatCapacity: 47.3 },
    { substance: null, deltaHf: -1473.2, deltaGf: -1362.2, entropy: 132.2, heatCapacity: 101.8 },
    { substance: null, deltaHf: 324, deltaGf: 286.6, entropy: 136.3, heatCapacity: 20.8 },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 9.5, heatCapacity: 13.4 },
    { substance: null, deltaHf: -353.5, deltaGf: null, entropy: 108, heatCapacity: 69.4 },
    { substance: null, deltaHf: -490.4, deltaGf: -445.6, entropy: 75.8, heatCapacity: 62.4 },
    { substance: null, deltaHf: -1026.8, deltaGf: -979.4, entropy: 53.4, heatCapacity: 51.8 },
    { substance: null, deltaHf: -192.5, deltaGf: null, entropy: 121, heatCapacity: 71.1 },
    { substance: null, deltaHf: -609.4, deltaGf: -580.1, entropy: 13.8, heatCapacity: 25.6 },
    { substance: null, deltaHf: -902.5, deltaGf: -815, entropy: 45.5, heatCapacity: 62.1 },
    { substance: null, deltaHf: -1205.2, deltaGf: -1093.8, entropy: 77.9, heatCapacity: 85.7 },
    { substance: null, deltaHf: 207.1, deltaGf: 168.2, entropy: 187, heatCapacity: 20.8 },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 56.7, heatCapacity: 25.5 },
    { substance: null, deltaHf: -573.9, deltaGf: -493.7, entropy: 151.5, heatCapacity: 113.5 },
    { substance: null, deltaHf: -379.1, deltaGf: -315, entropy: 177, heatCapacity: 105 },
    { substance: null, deltaHf: -121.4, deltaGf: -104, entropy: 82.6, heatCapacity: null },
    { substance: null, deltaHf: 111.9, deltaGf: 82.4, entropy: 175, heatCapacity: 20.8 },
    { substance: null, deltaHf: 30.9, deltaGf: 3.1, entropy: 245.5, heatCapacity: 36 },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 152.2, heatCapacity: 75.7 },
    { substance: null, deltaHf: 14.6, deltaGf: -1, entropy: 240.1, heatCapacity: 35 },
    { substance: null, deltaHf: -93.8, deltaGf: -109.2, entropy: 229, heatCapacity: 33 },
    { substance: null, deltaHf: -1136, deltaGf: null, entropy: 1119.4, heatCapacity: 254.4 },
    { substance: null, deltaHf: 716.7, deltaGf: 671.3, entropy: 158.1, heatCapacity: 0.8 },
    { substance: null, deltaHf: 1.9, deltaGf: 2.9, entropy: 2.4, heatCapacity: 6.1 },
    { substance: null, deltaHf: 0, deltaGf: 0, entropy: 5.7, heatCapacity: 8.5 },
    { substance: null, deltaHf: 83.9, deltaGf: 67, entropy: 358.1, heatCapacity: null },
    { substance: null, deltaHf: 29.4, deltaGf: null, entropy: 47.7, heatCapacity: 212.5 },
    { substance: null, deltaHf: -477.4, deltaGf: -439.4, entropy: 300.8, heatCapacity: null },
    { substance: null, deltaHf: -219.1, deltaGf: -204.9, entropy: 283.5, heatCapacity: null },
    { substance: null, deltaHf: -95.7, deltaGf: -53.6, entropy: 309.9, heatCapacity: null },
    { substance: null, deltaHf: -128.2, deltaGf: -62, entropy: null, heatCapacity: null }
  ]}
  xKey="deltaHf"
  title="Heat Capacity"
  source="engineeringtoolbox.com"
/>

## References

- [Original Source](https://www.engineeringtoolbox.com/standard-state-enthalpy-formation-definition-value-Gibbs-free-energy-entropy-molar-heat-capacity-d_1978.html)