ANALYTICAL CHEMISTRY FINAL- ACS EXAM QUESTIONS
AND ANSWERS A+ GRADED. BUY Quality Materials!
Selectivity
measure of freedom a method has of interferent
Sample Standard Deviation
measures the dispersion of a selected amount of data points in select set of points in a
population in regards to the mean
Systemmatic error
biases in experiment caused by the instrumentation. systemmatic error leads to less
accuracy
null hypothesis
statement that compares the significance of 2 values. Accepting the null hypothesis
means that the difference between the two data points can be explained by
indeterminate error
formality
concentration of a species without regards to its chemical form
Explain the difference between the sensititivity of an analytical method and the
limit of detection of a method
accuracy is how close a tested value is to the actual accepted value. Precision is how
close multiple tested values are relative to each other
What is the digestion of precipitates? If the AgCl precipitate mentioned above
was not digested, what problem(s) might have occurred?
Digestion is where you maintain equilibrium with the precipitate and its supernatant
solution for an extended period of time. If degestion had not occurred, then occlusions
and adsorbates might have formed. Also, it makes the precipitate less filterable
Why is EDTA, or other similar complexing agents, used for compleximetric
titrations rather than simpler monodenate ligands?
It is used because it is very stable, creates distinct endpoints, and does not form a
series of metal-ligand complexes
What are auxiliary reagents and how are they used in redox titrations?
auxiliary reagents are pretreatments. They are used in redox titrations to oxidize/reduce
the titrand into a single oxidiation state
What are control charts and why are they used in analytical labs?
a tool that provides a continuous record of quality assessment
results. They are used in order to tell if an analysis is in a state of statistical control
Describe a generic ISE
An ionic selector electode generally has 2 electrodes with an internal solution and an
outside solution. A membrane is used as the point at which electrons and ions can pass
through the membrane
Describe 2 reasons that can lead to incorrect results when using ISE's
contribution to the potential due to interferent ions, unsteady current passing through
the cell, differences in the analytes selectivity coefficient in the sample and the
standard, and junction potentials
AND ANSWERS A+ GRADED. BUY Quality Materials!
Selectivity
measure of freedom a method has of interferent
Sample Standard Deviation
measures the dispersion of a selected amount of data points in select set of points in a
population in regards to the mean
Systemmatic error
biases in experiment caused by the instrumentation. systemmatic error leads to less
accuracy
null hypothesis
statement that compares the significance of 2 values. Accepting the null hypothesis
means that the difference between the two data points can be explained by
indeterminate error
formality
concentration of a species without regards to its chemical form
Explain the difference between the sensititivity of an analytical method and the
limit of detection of a method
accuracy is how close a tested value is to the actual accepted value. Precision is how
close multiple tested values are relative to each other
What is the digestion of precipitates? If the AgCl precipitate mentioned above
was not digested, what problem(s) might have occurred?
Digestion is where you maintain equilibrium with the precipitate and its supernatant
solution for an extended period of time. If degestion had not occurred, then occlusions
and adsorbates might have formed. Also, it makes the precipitate less filterable
Why is EDTA, or other similar complexing agents, used for compleximetric
titrations rather than simpler monodenate ligands?
It is used because it is very stable, creates distinct endpoints, and does not form a
series of metal-ligand complexes
What are auxiliary reagents and how are they used in redox titrations?
auxiliary reagents are pretreatments. They are used in redox titrations to oxidize/reduce
the titrand into a single oxidiation state
What are control charts and why are they used in analytical labs?
a tool that provides a continuous record of quality assessment
results. They are used in order to tell if an analysis is in a state of statistical control
Describe a generic ISE
An ionic selector electode generally has 2 electrodes with an internal solution and an
outside solution. A membrane is used as the point at which electrons and ions can pass
through the membrane
Describe 2 reasons that can lead to incorrect results when using ISE's
contribution to the potential due to interferent ions, unsteady current passing through
the cell, differences in the analytes selectivity coefficient in the sample and the
standard, and junction potentials
