In the titration of a solution of weak monoprotic acid with a 0.1975 M solution of NaOH, the pH half way to the equivalence point was 4.30 . In the titration of a second solution of the same acid, exactly twice as much of a 0.1975 M solution of NaOH was needed to reach the equivalence point. What was the pH half way to the equivalence point in this titration

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.