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Halfway between each equivalence point, at 7.5 mL and 22.5 mL, the pH observed was about 1.5 and 4, giving the pK a. In weak monoprotic acids , the point halfway between the beginning of the curve (before any titrant has been added) and the equivalence point is significant: at that point, the concentrations of the two species (the acid and ...
The equivalence point, or stoichiometric point, of a chemical reaction is the point at which chemically equivalent quantities of reactants have been mixed. For an acid-base reaction the equivalence point is where the moles of acid and the moles of base would neutralize each other according to the chemical reaction.
Half maximal effective concentration (EC 50) is a measure of the concentration of a drug, antibody or toxicant which induces a biological response halfway between the baseline and maximum after a specified exposure time. [1] More simply, EC 50 can be defined as the concentration required to obtain a 50% [...] effect [2] and may be also written ...
The equivalence point occurs between pH 8-10, indicating the solution is basic at the equivalence point and an indicator such as phenolphthalein would be appropriate. Titration curves corresponding to weak bases and strong acids are similarly behaved, with the solution being acidic at the equivalence point and indicators such as methyl orange ...
The pH at the end-point or equivalence point in a titration may be calculated as follows. At the end-point the acid is completely neutralized so the analytical hydrogen ion concentration, T H, is zero and the concentration of the conjugate base, A −, is equal to the analytical or formal concentration T A of the acid: [A −] = T A.
However, there is disagreement among practitioners as to which data to plot, whether using only data on one side of equivalence or on both sides, and whether to select data nearest equivalence or in the most linear portions: [4] [5] using the data nearest the equivalence point will enable the two x-intercepts to be more coincident with each ...
A suitable pH indicator must be chosen in order to detect the end point of the titration. [10] The colour change or other effect should occur close to the equivalence point of the reaction so that the experimenter can accurately determine when that point is reached. The pH of the equivalence point can be estimated using the following rules:
A graph of potential against volume added can be drawn and the end point of the reaction is halfway between the jump in voltage. E cell depends on the concentration of the interested ions with which the indicator electrode is in contact. For example, the electrode reaction may be + +