Standard conditions are a pressure of 100kPa and a temperature of 298K
Enthalpy changes measured under standard conditions are called standard enthalpy changes.
Enthalpy changes are measured under a set of standard conditions as the enthalpy changes can vary with temperature, pressure or concentration. These are called standard enthalpy changes ΔHθStandard pressure is 100kPa (1 atmosphere of pressure is 101kPa)Standard temperature is 298KStandard concentration is 1 moldm-3The standard state of a substance is the physical state of a substance (solid, liquid or gas) under standard conditions.
Enthalpy changes measured under standard conditions are called standard enthalpy changes.
Enthalpy changes are measured under a set of standard conditions as the enthalpy changes can vary with temperature, pressure or concentration. These are called standard enthalpy changes ΔHθStandard pressure is 100kPa (1 atmosphere of pressure is 101kPa)Standard temperature is 298KStandard concentration is 1 moldm-3The standard state of a substance is the physical state of a substance (solid, liquid or gas) under standard conditions.