Titration curve A plot of the

In a typical acid-base titration (Section 3.10), a solution containing a known concentration of base (or acid) is added slowly from a buret to a second solution containing an unknown concentration of acid (or base). The progress of the titration is monitored, either by using a pH meter (Figure 16.6a) or by observing the color of a suitable acid-base indicator. With a pH meter, you can record data to produce a pH titration curve, a plot of the pH of the solution as a function of the volume of added titrant (Figure 16.6b). 

Derivative titration curve A plot of the change in the quantity measured per unit volume against the volume of titrant added a derivative curve displays a maximum where there is a point of inflection in a conventional titration curve. See also. second derivative curve. 

Acid-base titration curve a plot of the pH of a solution of acid (or base) against the volume of added base (or acid). (17.7)... 

Titration curve A plot of the pH of a solution as a function of the amount of strong acid or strong alkali added to it. 

Titration curve—A plot of pH vs. milliliter of titrant showing the manner in which pH changes vs. milliliter of titrant during an acid-base titration. 

Titration curve — A plot of a variable or function, usually linearly or logarithmically related to the concentration (- activity) of the analyte, versus the volume of - titrant added or the degree of titration. Two kinds of titration curves are commonly found, the first type is called -> linear titration curve while the second one is denominated logarithmic titration curve. These curves are helpful in judging the feasibility of a - titration and in selecting the proper indicator [i]. 

Periodic table a chart showing all the elements arranged in columns with similar chemical properties. (2.8) pH curve (titration curve) a plot showing the pH of a solution being analyzed as a function of the amount of titrant added. (8.5)... 

Fig. 9 shows the titration results for the following samples chloroplast lamellae and TSF-1 particles, both measured at 820 nm, and the CPI complex measured at 820 as well as 703 nm. Each sample was titrated oxidatively (starting with 100 pM ferrocyanide and adding ferricyanide to a maximum concentra tion of 10 mM) and reductively (starting with 1-5 mM ferricyanide and adding ferrocyanide to a maximum concentration of 10 mM). The titration is a plot of the light-induced AA V5. the actual redox-potential of the medium or the ferri-/ferrocyanide ratio as shown in Fig. 9. The plot of the data points clearly show that the titration was completely reversible and that P700 was in redox equilibrium with the ferri-/ferro-cya-nide couple. The solid line is the theoretical Nernst curve for a one-electron transition and the data points agree well with the theoretical course. The titration curve for both the chloroplast lamellae and the TSF-1, as well as D144 (data not shown here), yielded an value of+492 mV.

The data obtained will allow the plotting of what is called a titration curve, a plot of pH on the y-axis and the volume of NaOH added (in mL) on the x-axis. There are some unique features of this curve for each of the two acids in question and these will be the basis for the identification. What I suggest you do is create such a curve for both sulfuric acid and phosphoric acid. You can then create the same curve for the unknown waste acid and then match the curve for the unknown to that of one of the two acids and thereby identify it. Additional details are given in my attached procedure. 

In Chapter 4, we discussed the acid-base titration as an analytical method. Let s re-examine it, this time tracking the change in pH with an acid-base titration curve, a plot of pH vs. volume of titrant added. The behavior of an acid-base indicator and its role in the titration are described first. To better understand the titration process, we apply the principles of the acid-base behavior of salt solutions (Section 18.7) and, later in the section, the principles of buffer action. 

Titration curve (pH curve) a plot of the pH of a given solution versus the volume of titrant added to the solution. 

The pK of a compound is thus a description of the tendency of a compound to donate its titratable proton. A plot of the fractional proton occupancy of an acid or a base versus pH is called a titration curve and has the familiar sigmoid shape typical of binding reactions. 

Prei itation curve, Heidelberger curve a plot of the quantity of predpitate formed during titration of an antibody with an antigen, or vice versa. The antibody must be at least bivalent. The P.c. attains a max... 

Titration is the analytical method used to determine the amount of acid in a solution. A measured volume of the acid solution is titrated by slowly adding a solution of base, typically NaOH, of known concentration. As incremental amounts of NaOH are added, the pH of the solution is determined and a plot of the pH of the solution versus the amount of OH added yields a titration curve. The titration curve for acetic acid is shown in Figure 2.12. In considering the progress of this titration, keep in mind two important equilibria ... 

A plot of the pH of the analyte solution against the volume of titrant added during a titration is called a pH curve. The shape of the pH curve in Fig. 11.4 is typical of titrations in which a strong acid is added to a strong base. Initially, the pH falls slowly. Then, at the stoichiometric point, there is a sudden decrease in pH through 7. At this point, an indicator changes color or an automatic titrator responds electronically to the sudden change in pH. Titrations typically end at this point. However, if we were to continue the titration, we would find that the pH... 

In most cases, a curve is not drawn and the end point is taken as the milliliters (mL) used just when the color change takes place. There should be a half-drop of titrant difference between the change from one color to the next. In many cases, the color change is very light but distinctive. If the titration curve is plotted, then the end point can be determined by inspection or by taking the first or second derivative of the data to find the point of maximum slope. 

The volume of titrant added at the equivalence point of a titration can be accurately determined by plotting the first and second derivatives of the titration curve. A first derivative is a plot of the rate of change of the pH, ApH, vs. milliliters of titrant, and the second derivative is a plot of the rate of change of the first derivative, A(ApH), vs. milliliters of titrant. The plot in the center is the first derivative of the titration curve on the left, and the plot on the right is the second derivative. The rate of change of the curve on the left is a maximum at the midpoint of the inflection point, so the maximum on the first derivative coincides with this point, which is the equivalence point of the titration. Similarly, the rate of change is zero at the maximum of the curve in the center, so the equivalence point is also the point where the second derivative crosses zero. Thus, the equivalence point is the milliliters of titrant at the peak of the first derivative and the milliliters of titrant at the point where the line crosses zero for the second derivative. The second derivative provides the most precise measurement of the equivalence point. 

A plot of the pH of the analyte solution as a function of the volume of titrant added during a titration is called a pH curve (Fig. 11.4). The shape of the pH curve in the illustration is typical of titrations in which a... 

A pH titration curve is a plot of the pH of a solution as a function of the volume of base (or acid) added in the course of an acid-base titration. For a strong acid-strong base titration, the titration curve exhibits a sharp change in pH in the region of the equivalence point, the point at which stoichiometri-... 

Potentiometric titration curves normally are represented by a plot of the indicator-electrode potential as a function of volume of titrant, as indicated in Fig. 4.2. However, there are some advantages if the data are plotted as the first derivative of the indicator potential with respect to volume of titrant (or even as the second derivative). Such titration curves also are indicated in Figure 4.2, and illustrate that a more definite endpoint indication is provided by both differential curves than by the integrated form of the titration curve. Furthermore, titration by repetitive constant-volume increments allows the endpoint to be determined without a plot of the titration curve the endpoint coincides with the condition when the differential potentiometric response per volume increment is a maximum. Likewise, the endpoint can be determined by using the second derivative the latter has distinct advantages in that there is some indication of the approach of the endpoint as the second derivative approaches a positive maximum just prior to the equivalence point before passing through zero. Such a second-derivative response is particularly attractive for automated titration systems that stop at the equivalence point. 

As far as the determination of the composition of the complex is concerned, this can be obtained from the variation of electrical conductance of an ionic solution titrated with a solution of the neutral receptor as a result of the different mobilities of the species in solution. Plots of molar conductances, Am, against the ratio of the concentrations of the receptor and anion can provide useful information regarding the strength of anion-receptor interaction. In fact, several conclusions can be drawn from the shape of the conductometric titration curves. 

Table 1 tabulates literature values for acidity constants of seven amine-Ptn complexes with notations on the temperature, ionic strength, total Ptn concentration, method employed, conditions and other remarks, and the reference number. At least six factors enter into comparing determinations of a single complex. First is the purity of the complex under investigation. Because they rely on chemical shifts of an individual species, NMR methods are less dependent on purity than potentiometric titrations, which are interpreted on the basis of equivalents of added base. Rarely is the raw titration data published, but in one case it is evident from a plot of the data that the titration curve reveals up to about 10% impurity [7], Without knowing whether the impurities are acidic, basic, inert, or even forming during... 

Linear titration curve — A type of -> titration curve in which a variable that is directly proportional to the concentration of the titrand and/or -> titrant, and/or a product of their chemical reaction is plotted as a function of the volume of titrant added. Thus, a linear titration curve generally consists of two linear segments that have to be extrapolated to intersect at a point that is associated with the equivalence point. The measurements are performed below and above the zone of the equivalence point and preferably away from this last point where nonlinear behavior is commonly found [i]. Linear titration curves are typical for - amperometric titrations, and - conductometric titrations, whereas - poten-tiometrc titrations yield nonlinear curves (- logarithmic titration curve). 

Fig. 5. Difference between titration curves for a given type of group in two differ ent states of a given protein. The difference lies in the number of groups available for titration. The top figure shows the actual titration curves, the lower figure a plot of the difference between them.

A plot of the dependence of the pH of this solution on the amount of OH added is called a titration curve (Figure 3.61). Note that there is an inflection point in the curve at pH 4.8, which is the pK of acetic acid. In the vicinity of this pH, a... 

Figure 5. A plot of the amount of nuclease complex formed in the continuous variation titration experiments versus mole fraction of the R subunit as determined by densitometry of silver stained gels such as that shown in figure 4. The lines drawn are the theoretical curves expected for the association of 1 (. ..), 2 (-), or 3 (—) R subunits per molecule of MjS, mtase. The error bars are +/- one standard deviation.

Figure 4.12. Sketch of an acidimetric titration curve (a). In (b) the results of (a) are plotted in terms of Gian functions F, is multiplied by scale factors The F, values are defined by Equations 48 and 51-54. Xq, r , and v-i are the volumes of strong acid corresponding to the equivalence points / = 2,/ = 1, and / = 0, respectively.

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