Exam 2 Flashcards
Titration error is the difference between the end point and the equivalent point.
a. True
b. False
a. True
The smaller the Ksp of a precipitate, the more soluble in water.
a. True
b. False
b. False
The Volhard method involves a back titration of excess reagent silver ions with thiocyanate, as a means to determine concentration of halides such as chlorine that form insoluble precipitates with the silver ions reagent.
a. True
b. False
a. True
Suppose that in a gravimetric analysis, you forget to dry the filter crucibles before collecting precipitate. After filtering the product, you dry the product and crucible thoroughly before weighing them. Is the apparent mass of the product always high or always low?
a. Always high
b. Always low
a. Always high
In comparing two analytical methods, the method with better precision will always be the most accurate method to measure the concentration of a given analyte.
a. True
b. False
b. False
The chemical species C4H3O4- is amphiprotic (can act as both as an acid or base in a reaction)
a. True
b. False
a. True
In gravimetric analysis, the mass of a product is used to calculate:
a. The quantity of the original solvent.
b. The quantity of the original analyte.
c. The quantity of the impurity in solution.
d. The volume of the original solvent.
e. None of the above.
b. The quantity of the original analyte.
In the quality assurance process, the best way to get accuracy on the method:
a. Using calibration checks.
b. Having quality control samples.
c. Using fortification.
d. Employing blanks.
e. All of the above.
e. All of the above.
Which of the following is untrue regarding a blank solution?
a. Solutions containing known concentrations of analyte are called blank solutions.
b. A solution containing all of the reagents and solvents in the analysis and no analyte is called a blank solution.
c. A blank solution measures the response of the analytical procedure to interfering species or impurities in the reagents.
d. A blank solution is used to determine accuracy of the method.
e. None of the above.
a. Solutions containing known concentrations of analyte are called blank solutions.
A ____ is a sample that has been exposed to the site of sampling, containing all components except analyte, and it is taken through all steps of the analytical procedure.
a. Method blank
b. Reagent blank
c. Field blank
d. Spike blank
e. Matrix blank
c. Field blank
The smallest quantity of analyte that is significantly different from the blank expressed as 3 times the standard deviation, divided by the slope of the calibration curve is known as:
a. Lower limit of quantitation
b. Lower limit of detection
c. Upper limit of detection
d. Maximum detectable concentration
e. None of the above
b. Lower limit of detection
Back titration is a procedure in which:
a. Titrant is added to analyte until the reaction is complete.
b. Excess standard reagent is added to the analyte and the former is titrated with second standard reagent.
c. The reaction product is titrated with a second standard reagent.
d. Excess of analyte is titrated with a second standard reagent.
b. Excess standard reagent is added to the analyte and the former is titrated with second standard reagent.
A compound available in high purity, does not decompose under ordinary storage conditions and stable while being dried by heating or vacuum is a:
a. Secondary standard
b. Primary standard
c. Standard solution
d. Indicator
e. None
b. Primary standard
A(n) ___ is a compound with a physical property that changes abruptly near the equivalence point of a titration.
a. Primary standard
b. Titrant
c. Analyte
d. Indicator
e. Acid
d. Indicator
The key step to titration calculations is to relate:
a. Moles of titrant to moles of analyte
b. Volume of titrant to volume of analyte
c. Grams of titrant to grams of analyte
d. Conductivity of titrant to conductivity
a. Moles of titrant to moles of analyte.
