ppt_mixture {titrationCurves}

Precipitation Titration Curve: Mixture of Analytes

Description

This function calculates and plots the precipitation titration curve for a mixture of two analytes using a titrant that form precipitates with 1:1 stoichiometries. The calculation uses a single master equation that finds the volume of titrant needed to achieve a fixed concentration of titrant, expressed as pTitrant, as outlined in R. de Levie's Principles of Quantitative Chemical Analysis (McGraw-Hill, 1997).

Usage

ppt_mixture(conc.analyte1 = 0.05, conc.analyte2 = 0.05, vol.analyte = 25,
  conc.titrant = 0.05, pksp1 = 16.08, pksp2 = 11.97, plot = TRUE,
  eqpt = FALSE, overlay = FALSE, ...)

Arguments

conc.analyte1

Molar concentration of the first analyte; defaults to 0.050 M.

conc.analyte2

Molar concentration of the second analyte; defaults to 0.050 M.

vol.analyte

The initial olume, in mL, of the solution containing the analyte; defaults to 25.00 mL.

conc.titrant

Molar concentration of the titrant; defaults to 0.050 M.

pksp1

The pKsp value for the first analyte's precipitate; defaults to 16.08, which is the pKsp for AgI.

pksp2

The pKsp value for the second analyte's precipitate; defaults to 11.97, which is the pKsp for AgSCN.

plot

Logical; if TRUE, plots the titration curve.

eqpt

Logical; if TRUE, draws a vertical line at the titration curve's equivalence point.

overlay

Logical; if TRUE, adds the current titration curve to the existing titration curve.

...

Additional arguments to pass to plot() function.

Value

A two-column data frame that contains the volume of titrant in the first column and the solution's pTitrant in the second column. Also produces a plot of the titration curve with options to display the equivalence point and to overlay titration curves.

Author(s)

David T. Harvey, DePauw University. [e-mail]

Examples

### Simple titration curve with equivalence points
ex15 = ppt_mixture(eqpt = TRUE)
head(ex15)

### Overlay mixture titration curves using different pKsp values 
ppt_mixture(pksp1 = 16, pksp2 = 12, eqpt = TRUE)
ppt_mixture(pksp1 = 14, pksp2 = 10, overlay = TRUE)