What are equivalents in chemistry?

Equivalents in chemistry refer to a concept that allows different quantities to be compared or converted based on their chemical activity or properties. This often involves the use of stoichiometric relationships in reactions, where one can express the amounts of reactants and products in ratios that are consistent with their chemical formulas. This makes it possible to use various units to describe the same quantity in different contexts, which is what "units that can measure different quantities" encapsulates.

For example, when working with acids, one might measure solutions in equivalents, which relate to the number of reactive units (such as protons) that the acid can donate. In this way, it establishes a useful conversion factor between different substances based on their reactivity and allows chemists to work efficiently with chemical equations and reactions.

The other choices do not accurately encompass the idea of equivalents in the context of chemistry. Temperature measures are specific to thermodynamics but do not relate to the concept of chemical reactivity. The measurement of liquid volume is important in quantitative analysis but does not include the concept of equivalence. Lastly, while gas mixtures can involve proportional ratios, these ratios do not define the concept of equivalents, which is rooted in the notion of reactant capabilities rather than mixtures alone. Thus