JIZZ
Enthalpy can be zero for a pure substance at its standard state, where it is defined as the enthalpy of formation. This typically occurs at a reference temperature and pressure specified for the substance.
pure substance, propanone
Pure substance
it is a pure substance.... not
Methane is a pure substance.
pure substance
pure substance
Pure Substance
A pure substance is classified by having a definite and constant composition. The substance can be either an element or a compound, but what makes the substance pure, is that it does not vary.
Neon is a pure substance. Elements and compounds are pure substances; mixtures are not.
CH3COOH is a pure substance. It is the chemical formula for acetic acid.