It is globally accepted standard nomenclature for chemical compounds. By IUPAC system we can easily do the study and communicate globally.If nomenclature is local for each country then we can't do chemistry communication throughout the world.
A measure of acidity or alkalinity of water soluble substances (pH stands for 'potential ofHydrogen'). A pH value is a number from 1 to 14, with 7 as the middle (neutral) point. Values below 7 indicate acidity which increases as the number decreases, 1 being the most acidic and 14 being the most basic.