Acid-base titrations (neutralisation titrations)
One of the most accurate and simplest measurement-analytical titration methods is the acid-base titration. As can be seen from the name, an acid and a base are made to react until they are completely neutralised - my homework . The concentrations of acid or base in the analysis solution are calculated from the consumption of the measuring solution up to the equivalence point.
This takes advantage of the fact that the hydrogen ions (hydronium ions) of the acid solution react with the hydroxide ions of the base solution to form water molecules and the pH value of the solution changes accordingly - https://domyhomework.club/same-day-essay-writing-service/ . At the equivalence point, the amounts of acid and base are exactly equal.
NaOH (aq) + HCl(aq) ⇄ NaCl(aq) + H2O(l) Equivalence point: n(NaOH) = n(HCl)
Acid-base indicators are often used to determine the equivalence point (AeP). They indicate the change in pH value by changing colour. The colour change of the indicator characterises the point at which the amount of substance of the added hydroxide ions corresponds to the amount of substance of the hydrogen ions (hydronium ions) present in the analysis solution.
Acid-base titration - Representation of a titration
If you graphically represent the course of an acid-base titration, you get a titration curve. The pH value is plotted on the ordinate and the consumption of measuring solution on the abscissa. With electronic measuring instruments, such as a pH meter, the change in the pH value can be measured and then plotted.
If the curve is viewed mathematically, an inflection point of the function can be calculated - chemistry problem solver . This corresponds to the equivalence point mentioned above, at which the amount of substance of the added measuring solution is equal to the amount of substance of the unknown analysis solution.
The course of such a titration curve depends strongly on the acids and bases involved. The values determined during the titration are used as the basis for the calculation.