2.1 Basic terms in thermodynamics -2.1.1 System and surroundings 2.1.2 State and state functions 2.1.3 Process and path 2.1.4 Phase -2.1.5 Stoichiometric equation and extent of reaction§2.1 Basic terms in thermodynamics 2.1.1 System and surroundings 2.1.5 Stoichiometric equation and extent of reaction 2.1.4 Phase 2.1.3 Process and path 2.1.2 State and state functions