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An acid–base titration is a method of quantitative analysis for determining the concentration of Brønsted-Lowry acid or base (titrate) by neutralizing it using a solution of known concentration (titrant). [1] A pH indicator is used to monitor the progress of the acid–base reaction and a titration curve can be constructed.
Henderson–Hasselbalch equation. In chemistry and biochemistry, the Henderson–Hasselbalch equation relates the pH of a chemical solution of a weak acid to the numerical value of the acid dissociation constant, Ka, of acid and the ratio of the concentrations, of the acid and its conjugate base in an equilibrium. [1]
If one reagent is a weak acid or base and the other is a strong acid or base, the titration curve is irregular and the pH shifts less with small additions of titrant near the equivalence point. For example, the titration curve for the titration between oxalic acid (a weak acid) and sodium hydroxide (a strong base) is pictured.
For example, acetic acid is a weak acid which has a = 1.75 x 10 −5. Its conjugate base is the acetate ion with K b = 10 −14 /K a = 5.7 x 10 −10 (from the relationship K a × K b = 10 −14), which certainly does not correspond to a strong base. The conjugate of a weak acid is often a weak base and vice versa.
A Gran plot (also known as Gran titration or the Gran method) is a common means of standardizing a titrate or titrant by estimating the equivalence volume or end point in a strong acid -strong base titration or in a potentiometric titration. Such plots have been also used to calibrate glass electrodes, to estimate the carbonate content of ...
Titration curves for addition of a strong base to a weak acid with pK a of 4.85. The curves are labelled with the concentration of the acid. where K w represents the self-dissociation constant of water. Since K w = [H +][OH −], the term K w / [H +] is equal to [OH −], the concentration of hydroxide ions. At neutralization, T H is zero.
A typical titration curve of a diprotic acid, oxalic acid, titrated with a strong base, sodium hydroxide.Both equivalence points are visible. Titrations are often recorded on graphs called titration curves, which generally contain the volume of the titrant as the independent variable and the pH of the solution as the dependent variable (because it changes depending on the composition of the ...
Speciation of ions refers to the changing concentration of varying forms of an ion as the pH of the solution changes. [ 1] The ratio of acid, AH and conjugate base, A −, concentrations varies as the difference between the pH and the p Ka varies, in accordance with the Henderson-Hasselbalch equation. The pH of a solution of a monoprotic weak ...