Hasok Chang on the nature of acids

Abstract For a period of several years the philosopher science Hasok Chang has promoted various inter-related views including pluralism, pragmatism, and an associated view natural kinds. He also argued for what he calls persistence everyday terms in scientific view. claims that like phlogiston were never truly abandoned but became transformed into different concepts remain useful. On other hand, argues some such as acidity have suffered form “rupture”, especially case modern Lewis definition acids. complains degree acid cannot be measured using pH meter seems to regard this serious problem. The present paper examines these views, rupture acidity. It is suggested there been no genuine generalization, on moving from Brønsted-Lowry theory will shown how quantification measurement can easily realized through use equilibrium stability constants.