Give two examples of a chemical system and define the ‘universe’ in terms of those examples.

Example 1:

Example 2:

Explanation:

In general, in science, a system is the specific part of the universe that is being studied. Everything that is not the system is considered the surroundings.

So, the universe is the system plus the  surroundings:

Chemistry is the science of the chemical reactions, so a chemical system is the chemical reaction.

Expample 1:

A simple example of a system is the reaction of  solid sodium and water to produce sodium hydroxide solution plus hydrogen:

The surroundings, in this case, is the beaker that contains the reactants (sodium and water) and the aqueous product (sodium hydroxide), such as tha apparatus used to collect the hydrogen (gas). Also, the surroundings contains the air or atmosphere with which the reaction exchanges heat. If you are holding the beaker with your hands, your hands will feel (and absorb part of) the heat, so your hands would be part of the surroundings.

Summarizing, for the reaction of sodium and water, to produce sodium hydroxide and hydrogen gas, the system is the reactants and products, and the universe are the reaction plus the containers, the air , and your hands.

Example 2:

Other example of a chemical system is the photosynthesis reaction:

c

explanation: