1.14.68: Surroundings and System
System
The word ‘system’ describes that part of the universe which we have identified for the purpose of studying its chemical properties. The term "universe" in the latter sentence is somewhat pretentious (= implying ‘of enormous importance’ in a way that is doubtful). From the practical point of view, a chemist identifies the system as the contents of the reaction vessel (flask) under investigation.
Surroundings
The rest of the universe comprises the surroundings. We as observers of the properties plus all our measuring equipment including spectrophotometers and calorimeters are part of the surroundings. As far as chemists are concerned the surroundings mean the laboratory (+ chemist!) surrounding the system.