Symbols Used to Denote a Chemical Reactions and Process or Condition
Explanation of symbols used as subscripts or superscripts to tell more about the type of chemical reaction, process or condition. This tool helps identify and understand the meaning of various symbols used in thermodynamic expressions and chemical equations.
Subscript Symbols Used to Denote Chemical Reactions or Process Conditions
| Subscript Symbol | Process |
|---|---|
| ads | adsorption |
| at | atomization |
| c | combustion reaction |
| dil | dilution (of a solution) |
| dpl | displacement |
| f | formation reaction |
| fus | melting, fusion (solid → liquid) |
| imm | immersion |
| mix | mixing of fluids |
| r | reaction in general |
| sol | solution (of solute in solvent) |
| sub | sublimation (solid → gas) |
| trs | transition (between two phases) |
| vap | vaporization, evaporation (liquid → gas) |
Superscript Symbols Used to Denote Chemical Reactions or Process Conditions
| Superscript Symbol | Process |
|---|---|
| app | apparent |
| ≠, ‡ | activated complex, transition state |
| E | excess quantity |
| id | ideal |
| ∞ | infinite dilution |
| * | pure substance |
| °, θ | standard |
Examples of Use
ΔGᵣ : Change in Gibbs free energy by (a given) reaction
ΔHₛₒₗ : Change in enthalpy by (a given) solution
ΔSᵥₐₚ : Change in entropy by (a given) evaporation
pθ : Pressure at standard state (normally 1 bar)