Acid-Base Titrations And Neutralization Methods Flashcards
It is based on a reaction between an analyte and a standard solution called titrant.
Titration
An ultra pure reagent where the solution of unknown concentration is compared to.
Titrant
Common primary standard for NaOH
Potassium Hydrogen Phthalate (KHP)
KHC8H4O4
The _____ of a titration is based upon experimental observation, whereas the ____ is the theoretical point reached when the amount of titrant is equivalent to amount of analyte present
End point, equivalence point
KHP is a weak monoprotic acid, white, soluble solid that is commercially available in highly pure form.
True
Used to observe the end point during titration
Indicator
Common indicator in acid-base titrations which turns pink when the solution becomes basic
Phenolphthalein
Measure of the acid -neutralizing capacity of a water sample
Alkalinity
When sources of alkalinity are limited to carbonates (OH-, HCO3-, CO32-), _____are often employed
Double indicator titrations
Titrations at pH ___ (bromocresol green endpoint) and pH ___ (phenolphthalein end point) can be used to determine which species are present, and their respective co centrations
4.5, 8.3
What are the constituents of the sample if Vphth=Vbcg
OH-
Which are the limitations of the Warder method (direct titration)?
I. Diffused endpoints
II. Possible loss of CO2 from the reaction of HCO3- and acid
III. Possible small errors in calculations of OH- and CO32-
I and II
____ counters the limitations of Wardnder methods
Wrinkler methods (indirect titrations)
Elemental analyses are often performed with _____ as the final step
Acid-base titrations
Used for nitrogen determination.
Kjeldahl analysis
Used to calculate protein content of certain food samples using the %N determined. In kjeldahl method
Jones factor
The identity of an unknown weak acid or weak base can be established by determining the _____ at half equivalence point and the ______ at equivalence point.
Ionization constant, equivalent weight
One way to overcome wardner titration, specifically to precipitate CO32- , ______ is added leaving the other component to be titrated by standard acid.
BaCl2
One way to overcome wardner titration, specifically to avoid large errors in calculations for samples containing OH- and CO32-, back titration of _______ with _______ is done.
Excess NaOH, standard HCl
In what region in titration curve of weak acid/base with strong base/acid titrant does the analyte = conjugate, and pH=pKa
At half equivalence point
In what region in titration curve of weak acid/base with strong base/acid titrant does the conjugate ionize?
At equivalence point
What is the recommended pairing of analyte and titrant?
Strong acid-strong base
